Transition from transperitoneal to retroperitoneal approach in laparoscopic living donor nephrectomy: team-based and individual learning curve: a cross-sectional study

Irfan Wahyudi; Ilham Azka Adriansyah; Kevin Yonathan; Fina Widia; Agus Rizal A Hamid; Chaidir Arif Mochtar

doi:10.12688/f1000research.129479.1

Home Browse Transition from transperitoneal to retroperitoneal approach in laparoscopic...

ALL Metrics

-

Views

-

Downloads

Get PDF

Get XML

Export

▬

✚

Research Article

Transition from transperitoneal to retroperitoneal approach in laparoscopic living donor nephrectomy: team-based and individual learning curve: a cross-sectional study

[version 1; peer review: 2 approved with reservations]

Irfan Wahyudi¹, Ilham Azka Adriansyah¹, Kevin Yonathan¹, Fina Widia¹, Agus Rizal A Hamid¹, Chaidir Arif Mochtar¹

Irfan Wahyudi¹, Ilham Azka Adriansyah¹, [...] Kevin Yonathan¹, Fina Widia¹, Agus Rizal A Hamid¹, Chaidir Arif Mochtar¹

PUBLISHED 04 May 2023

Author details Author details

¹ Department of Urology, University of Indonesia, Jakarta, DKI Jakarta, 10430, Indonesia

Irfan Wahyudi
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

Ilham Azka Adriansyah
Roles: Conceptualization, Data Curation, Formal Analysis, Investigation, Methodology, Project Administration, Resources, Software, Validation, Writing – Original Draft Preparation, Writing – Review & Editing

Kevin Yonathan
Roles: Conceptualization, Data Curation, Methodology, Project Administration, Resources, Writing – Original Draft Preparation, Writing – Review & Editing

Fina Widia
Roles: Conceptualization, Formal Analysis, Resources, Validation, Writing – Review & Editing

Agus Rizal A Hamid
Roles: Conceptualization, Formal Analysis, Resources, Writing – Review & Editing

Chaidir Arif Mochtar
Roles: Conceptualization, Investigation, Methodology, Resources, Writing – Review & Editing

OPEN PEER REVIEW

REVIEWER STATUS

Abstract

Background: Laparoscopic living donor nephrectomy (LLDN) is a standard practice for kidney donor transplantation due to fewer complications associated with the treatment. Retroperitoneal approach to LLDN is thought to be more advantageous in preventing injuries to various abdominal organs. However, the transition process from transperitoneal to retroperitoneal LLDN is important to ensure the best outcome for the patients. The aim of this study was to investigate the learning curve for retroperitoneal approach in LLDN among urologists in an individual and team-based approach
Methods: A retrospective analysis of retroperitoneal LLDN was performed on procedures performed by a kidney donor team consisting of four urologists from January 2019 to January 2022 at Cipto Mangunkusumo National General Hospital, Indonesia. The data were taken from pre-existing medical records. The learning curve for the operation time, warm ischemic time, and estimated blood loss was analyzed using cumulative sum (CUSUM) analysis. Phase 1 represents the initial learning curve, the phase 2 plateau represents the period of proficiency, while phase 3 represents the mastery period.
Results: A total of 127 retroperitoneal LLDN procedures were done during the study period by four operators with various experience. The average procedure needed to achieve proficiency was 16.5 procedures. Meanwhile, the average procedure needed to achieve mastery was 28 procedures. Shorter learning curve was achieved by operators with more experience in other laparoscopic procedures.
Conclusions: The learning curve for transition from transperitoneal to retroperitoneal approach to LLDN is relatively short and feasible for both individuals and teams of urologists. Therefore, transition to retroperitoneal approach is a feasible option to reduce the complication rate of LLDN.

Keywords

kidney donor, laparoscopy, nephrectomy, transplantation

Corresponding author: Irfan Wahyudi

Competing interests: No competing interests were disclosed.

Grant information: The funding for this study was partially fulfilled by Universitas Indonesia with International Indexed Publication Grant Program (PUTI) [grant number NKB-1235/UN2.RST/HKP.05.00/2022]

Copyright: © 2023 Wahyudi I et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

How to cite: Wahyudi I, Adriansyah IA, Yonathan K et al. Transition from transperitoneal to retroperitoneal approach in laparoscopic living donor nephrectomy: team-based and individual learning curve: a cross-sectional study [version 1; peer review: 2 approved with reservations]. F1000Research 2023, 12:464 (https://doi.org/10.12688/f1000research.129479.1) First published: 04 May 2023, 12:464 (https://doi.org/10.12688/f1000research.129479.1) Latest published: 04 May 2023, 12:464 (https://doi.org/10.12688/f1000research.129479.1)

Introduction

Kidney transplantation is the best available option for the management of end stage renal disease (ESRD).¹ Transplantation reduces the risk of cardiovascular and mortality events, while also improving quality of life compared to chronic hemodialysis.² Living donor transplantation is preferred over deceased donor, as it has better survival rates and less delayed graft function.³^,⁴ Laparoscopic living donor nephrectomy (LLDN) is the standard surgical practice due to fewer complications associated with the treatment.⁵ This technique includes standard laparoscopic, hand-assisted laparoscopic, hand-assisted retroperitoneoscopic, pure retroperitoneoscopic, and robot-assisted live donor nephrectomy.⁶^–⁹

Previous studies have shown that the retroperitoneal approach to LLDN has more advantages than the transperitoneal approach; namely shorter access to renal arteries and veins, better visualization during donor nephrectomy, and prevention of injuries of the liver, spleen, and bowel.¹⁰^–¹³ However, some adjustments to the techniques require additional training for the operators performing the technique. Evaluation of surgical practice performances could be done using the learning curve.¹⁴ However, there has only a few studies regarding the learning curve of the retroperitoneal approach of LLDN. Moreover, a previous study only analyzed learning curve on a single operator, although LLDN is usually performed by a team.¹⁵

Therefore, this study aims to investigate the learning curve for retroperitoneal approach in LLDN among urologists in an individual and team-based approach.

Methods

A retrospective analysis of laparoscopic living donor nephrectomy (LLDN) procedures was done on four different urologists (operators) with different levels of experience from January 2019 to January 2022 at Cipto Mangunkusumo National General Hospital, Indonesia. All of the operators in our kidney donor team were included in this study. The date was determined as the first LLDN in our center was performed in January 2019 while the endpoint was the most recent date that the yearly review of the procedure was carried out.

Ethical Approval to conduct this study was issued by the ethics committee of the Faculty of Medicine Universitas Indonesia–Cipto Mangunkusumo Hospital (KET-720/UN2.F1/ETIK/2018). All patients had received detailed preoperative counselling and their decision to undergo the procedure was taken with written informed consent prior to the surgery. Meanwhile, the data used in this study were collected from the medical records of the patients. The written permission was granted by the ethics committee of the Faculty of Medicine Universitas Indonesia–Cipto Mangunkusumo Hospital for the publication of the study results.

Demographical data was collected from the electronic medical record, including age, sex, and body mass index (BMI, calculated as weight in kilograms divided by square of height in meters). Preoperative data included number of arteries involved and side of the donor kidney. Intraoperative data included surgery duration, warm ischemic time (WIT), and estimated blood loss (EBL). Surgery duration was determined as the length of time from the first incision to renal artery clamping, as the final closure was sometimes done by the residents due to the study location being a teaching hospital. WIT was documented as the length of time from clamping to cold ischemic time. Postoperative complication was documented in accordance to the pre-existing data in the medical records.

Operative technique

The operative technique used in this study has been reported in other publications and become the routine technique used in our center, including for the subjects in this study.⁸^,¹⁶ The LLDN was done under general anesthesia and the donor was positioned in the lateral decubitus position. First incision was then made one finger below the 12^th rib with open approach (Hasson technique) to reach access to retroperitoneal space. Retroperitoneal space was created using balloon dilator. Afterward, an 11 mm trocar was then inserted into retroperitoneal space for camera. Other two incisions were made in line: one at the costovertebral angle and one the above anterior superior iliac spine. Pneumoretroperitoneum was created using a carbon dioxide (CO₂) insufflation and the pressure maintained at 12 mmHg. The psoas muscle was identified and the Gerota fascia was incised to expose the ureter. Furthermore, the gonadal vein was identified, and its course was followed upward to find the renal vein. Each renal pedicle was identified individually and dissected. Perirenal fat was then dissected from renal parenchyma and the kidney was mobilized. Further dissection was performed to renal artery until its base at aorta and renal vein until below gonadal and adrenal tributaries. The ureter was dissected until the distal part near its crossing to iliac vessel. Retrieval of the kidney was done via suprapubic access created through a modified Pfannenstiel incision.

Operators

In this study, the procedures were performed by four urologists, namely surgeon 1 (S1), surgeon 2 (S2), surgeon 3 (S3) and surgeon 4 (S4). S1 was a urologist with more than 15 years of laparoscopy experience, S2 was a urologist with more than nine years of laparoscopy experience, S3 was a urologist with more than eight years of experience, while S4 was a urologist with more than four years of experience. All of the urology surgeons had performed more than 100 transperitoneal approach LLDN with limited experiences in retroperitoneal approach for other laparoscopic urology procedures, such as partial nephrectomy, adrenalectomy, unroofing renal cyst and proximal ureterolithotomy.

The learning method for retroperitoneal approaches used was done by viewing the video and visiting urology centers which are familiar with retroperitoneal approach of laparoscopy procedures, either for LLDN or for other nephrectomy procedures. The urology centers visited for the study were The Academic Medical Center, University of Amsterdam (Amsterdam, Netherlands), Radboud University Medical Center (Nijmegen, Netherlands), and SLK Kliniken Heilbronn GmbH (Heilbronn, Germany).

The average of LLDN surgery in our hospital was between two and three surgeries per week. As per the protocol in our center, all the surgeons were arranged to have fair and similar opportunity to perform retroperitoneal approach LLDN regularly, including in the transition process.

Statistical analysis

Cumulative sum (CUSUM) analysis was performed with SPSS version 20 (RRID:SCR_016479)(IBM Corp, 2011)¹⁷ to investigate individual surgeon operative time learning curves to reach optimal performance. Team-based analysis was separately performed to analyze the operative time by all of the four urologists. Three indicators, namely duration of surgery, WIT, and EBL were collected from pre-existing medical records and evaluated to represent the learning process taking place as the surgery repetition occurred. The CUSUM is the running total of differences between the individual data points and the mean of all data points, thus it can be performed recursively. The cases were ordered chronologically from the earliest to the most recent. The surgery duration for each case was defined as x_i and the mean surgery duration of all cases was defined as μ. Therefore, the CUSUM at surgery duration n (CUSUM_SDn) might be calculated as follow:

{CUSUM}_{SDn} = \sum_{i = 1}^{n} x_{i} - μ

The CUSUM_SD1 of the first case was the difference between the duration of surgery for the first case and the μ. The CUSUM_SD2 of the second case was the previous case’s CUSUM_SD added to the difference between the duration of surgery for the second case and the μ. The process then continued until the CUSUM_SD for the last case was calculated.¹⁸

All of the surgeons in this study experienced three learning phases as described in a previous study.¹⁸ The three phases of the learning curve were identified by the inflection point of the CUSUM curve. Phase 1 (learning period) showed an expected incline in CUSUM curve which was the initial learning curve, phase 2 (proficiency) showed a decline in CUSUM curve, with a plateau which was the proficient phase with additional experience obtained leading to the achievement of expert competence. Phase 3 was defined as the post-learning (mastery) period, as seen in typical learning curve studies in which there was steeper decline of the CUSUM curve.

To determine the difference of characteristics and outcomes between phases, the Chi-square test was used to analyze categorical data and Wilcoxon test was used to analyze numerical data. All statistical tests were 2-tailed, and a p-value of < 0.05 was considered to as statistical significance. The statistical analyses were performed with SPSS version 20 (RRID:SCR_016479) (IBM Corp, 2011).

Results

A total of 127 patients underwent LLDN during the three years [30], with 31 operations done by S1, 30 operations by S2, 38 operations by S3, and 28 operations by S4. There was no conversion to open nephrectomy during the surgeries performed in this study.

Individual learning curve of retroperitoneal LLDN operator

CUSUM analysis of LLDN operative time is shown in Figure 1. Based on the analysis of each surgeons, the average number of procedures needed to achieve proficiency (phase 2) was 16.5. Meanwhile, the average number of procedures needed to achieve mastery (phase 3) was 28. However, S4 did not achieve mastery during the study, thus the average number of procedures needed to achieve mastery was calculated only for S1, S2, and S3.

Figure 1. Cumulative SUM (CUSUM) for operation time of Laparoscopic Living Donor Nephrectomy (LLDN).

(a) Surgeon 1 (15+ years of exp), (b) Surgeon 2 (9+ years of exp), (c) Surgeon 3 (8+ years of exp), (d) Surgeon 4 (4+ years of exp).

Team-based learning curve of retroperitoneal LLDN operator

Based on the analysis, it can be assumed that the number of procedures needed as a team to achieve proficiency (phase 2) was 66 procedures, while the number of procedures needed as a team to achieve mastery (phase 3) was 106 procedures (Figure 2).

Figure 2. Team-based learning curve of retroperitoneal Laparoscopic Living Donor Nephrectomy (LLDN) Operator.

Clinical outcome compared to experience

There was a significant reduction in operative time after proficiency and mastery of LLDN (P < 0.001). Meanwhile, intraoperative WIT, EBL, and postoperative complication shows no significant difference between phases (Table 1).

Table 1. Clinical outcome of donors in each phase.

Variables	Phase 1 (n = 66)	Phase 2 (n = 40)	Phase 3 (n = 21)	p
Age (years), median (min-max)	47 (22-71)	41.5 (22-65)	37 (23-68)	0.073
Sex				0.189
Male	26 (39.4%)	19 (47.5%)	13 (61.9%)
Female	40 (60.6%)	21 (52.5%)	8 (38.1%)
BMI (kg/m²), median (min-max)	25.2 (15.6-32.8)	24.3 (17.0-36.1)	24.5 (17.4-32.5)	0.626
Side of donor kidney transplanted				1.000
Left	66 (100%)	40 (100%)	21 (100%)
Right	0	0	0
Arteries				0.347
Single	55 (83.3%)	37 (92.5%)	19 (90.5%)
Multiple	11 (16.7%)	3 (7.5%)	2 (9.5%)
Surgery duration (min), median (min-max)	186 (110-345)	150 (85-289)	140 (90-230)	< 0.001
WIT, median (min-max)	4.05 (2.12-13.32)	4.02 (2.33-11.65)	3.53 (3.07-7.43)	0.315
EBL (mL), median (min-max)	70 (10-340)	50 (30-200)	75 (20-300)	0.876
Complications				0.223
None	62 (93.9%)	34 (85.0%)	20 (95.2%)
Pain	3 (4.6%)	4 (10.0%)	1 (3.6%)
Chylous ascites	1 (1.5%)	2 (5.0%)	0

Discussion

Minimally invasive techniques are the preferred technique for donor nephrectomy compared to open nephrectomy. Studies found that a minimally invasive approach is associated with perioperative lower blood loss, lower morbidity,¹⁹ reduced analgesia use, shorter length of stay, and faster recovery.⁵ Retroperitoneal approach or retroperitoneoscopic provides direct access to renal hilum without moving abdominal organs. Therefore, injury or bleeding of the organs could be avoided and bowel function may return rapidly following the surgery.¹⁰^,²⁰ The crucial disadvantage of this procedure was the difficulty to orient the landmark due to the limited working space of the retroperitoneal approach in LLDN.²¹ In terms of the learning curve, retroperitoneal approach is more technically demanding and has a steeper learning curve than the transperitoneal approach.²²^–²⁴

Learning curves represent the relationship between learning repetition and practice performance.²⁵ There are several methods that can be used to analyze the learning curves other than CUSUM analysis, such as graphical visual inspection, split-group method, and regression techniques. CUSUM method is considered the sensitive method adopted by surgical practice for self-and supervisor assessment. This method uses plotted graph and gives accurate progression and level of performance, thus, it can be used to show a process of achieving and maintaining a surgical technique proficiency.¹⁴

A comparison study of retroperitoneoscopic donor nephrectomy by a single surgeon between a high volume and a low volume hospital by van der Merwe et al. describes the learning curve differences in surgery time and WIT. This study shows the improvement based on the graph decline.¹¹ Meanwhile, a learning curve study of retroperitoneoscopic donor nephrectomy by Pal et al. analyzes the performance changes between three groups using the split-group method. However, this method has several biases based on its arbitrary group size option and uncertain changes.²⁶

In our CUSUM analysis study, on an individual level, an average of 16.5 procedures was needed to achieve proficiency and 28 procedures to acquire mastery in the transition from transperitoneal to retroperitoneal approach. There were some differences between the results of this study and other learning curve studies of the retroperitoneal approach of LLDN. Pal et al.²⁶ found a significantly reduced surgery time after 34 pure laparoscopic retroperitoneal nephrectomies. Chin et al.,¹⁵ though, observed a substantial difference in surgery time after 150 cases, although this study did not use the CUSUM model analysis. The second reduction of operation time or mastery is found after 300 laparoscopic nephrectomies in a study by Nakajima et al.²⁷ However, the procedures needed to achieve both proficiency and mastery in our study differed on each operator. Operator 1 who had more experience in other surgeries only needed 12 procedures before achieving proficiency, while other operators needed more procedures in accordance with their prior experiences.

Based on the CUSUM analysis, it was found that 66 procedure was needed to achieve proficiency (phase 2) and 106 procedures to acquire mastery (phase 3) for team-based approach of the transition from transperitoneal to retroperitoneal LLDN. Team-based analysis shows a more gradual improvement in operation time compared an individual surgeon-based analysis. A study by van der Merwe et al. shows that the subgroup analysis of a single surgeon shows a more graphically evident improvement in operation time than the team-based analysis.²⁴ However, LLDN is usually approached by several operators, as it is technically demanding and require a significant amount of time.

Several variables could affect the learning curve of the retroperitoneal approach of LLDN. The technical skills of each surgeon are related to shorter surgery time and lesser complications. The advantages of the retroperitoneal approach may relate to the surgeon’s experience as the vessel injury, or surgical complications were lower in the more experienced surgeon.¹⁰^,¹⁹ In this study, urologists that have more experience achieve proficiency in operation time in fewer procedures. A study by Zhang et al. showed that senior surgeons had a better learning curve for laparoscopic procedures. Operation time was also significantly faster, with a lower conversion rate to open surgeries.²⁸ Proficiency-based guidance, part-task training, and assigning practice over time might optimize the learning curve.²⁹ There were other problematic factors, such as obese donors prolonged the surgery time then affected the learning curve.⁶ A few millimeters of perinephric fat would significantly prolong the surgery time.³⁰

A limitation of the study is in the methodology as it is a retrospective study based on pre-existing medical records and done in a single center. Therefore, information bias may occur due to the data input, processing, and collection. Moreover, being a teaching hospital, the performance of urology residents as the operative assistant may create another bias, especially for the operative time. However, we have limited the calculated operative time to only from the first incision to renal artery clamping, as the final closure was sometimes done by the residents.

Conclusions

Transition from transperitoneal to retroperitoneal approach in laparoscopic living donor nephrectomy has a certain learning curve time to achieve proficiency and mastery, both on the individual and team-based analysis. Prior experience and focused training may improve the learning process. The transition to retroperitoneal approach is a feasible option to improve the outcome of LLDN.

Authors’ contributions

IW involved in conceptualization, protocol development, administration of the study, data collection, funding, manuscript writing, and manuscript finalization.

IAA involved in conceptualization, protocol development, administration of the study, data collection, and manuscript finalization.

KY involved in conceptualization, protocol development, administration of the study, data collection, and manuscript finalization.

FW involved in protocol development, study conceptualization, patient recruitment, and manuscript editing and finalization.

ARAH contributed in protocol development, study conceptualization, patient recruitment, and manuscript editing and finalization.

CAM contributed in protocol development, study conceptualization, patient recruitment, and manuscript editing and finalization.

All authors read and approved the final manuscript.

Ethics approval and consent to participate

Ethical Approval to conduct this study was issued by the ethics committee of the Faculty of Medicine Universitas Indonesia–Cipto Mangunkusumo Hospital (KET-720/UN2.F1/ETIK/2018). Written informed consent was obtained from the patient for the surgery performed in this study. Written informed consent was obtained from a guardian for participants under 18 years old. Written permission was granted by the ethics committee of the Faculty of Medicine Universitas Indonesia–Cipto Mangunkusumo Hospital for the publication of the study results.

Data availability

Underlying data

The data used in this study were provided from pre-existing medical records of kidney donor patients in Cipto Mangunkusumo National Hospital, Indonesia. The authors obtained the data by submitting the ethical clearance to the research ethics of Faculty of Medicine, University of Indonesia, and requesting the written research permit for the data to the Innovation and Intellectual Property Management Installation of Cipto Mangunkusumo National Hospital, Indonesia.

The access to the same data will be provided following the formal ethical clearance request to the research ethics of Faculty of Medicine, University of Indonesia, and formal research permit request to the the Innovation and Intellectual Property Management Installation of Cipto Mangunkusumo National Hospital, Indonesia.

Extended data

Drayad: Transition from transperitoneal to retroperitoneal approach in laparoscopic living donor nephrectomy: Team-based and individual learning curve: A cross-sectional study https://doi.org/10.5061/dryad.3tx95x6kq.³¹

This project contains the following extended data:

- Dataset.sav (SPSS file containing all aggregated data in this study).

Data are available under the terms of the Creative Commons Zero “No rights reserved” data waiver (CC0 1.0 Public domain dedication).

Acknowledgments

The authors would like to express the greatest gratitude for all the medical staffs and patients of Urology Department, Cipto Mangunkusumo National General Hospital, Indonesia who were willing to support the study.

References

1. Lee L-Y, Pham TA, Melcher ML: Living Kidney Donation: Strategies to Increase the Donor Pool. Surg. Clin. N. Am. 2019; 99: 37–47. PubMed Abstract | Publisher Full Text
2. Tonelli M, Wiebe N, Knoll G, et al.: Systematic Review: Kidney Transplantation Compared With Dialysis in Clinically Relevant Outcomes. Am. J. Transplant. 2011; 11: 2093–2109. Publisher Full Text
3. Gjertson DW, Cecka JM: Living unrelated donor kidney transplantation. Kidney Int. 2000; 58: 491–499. Publisher Full Text
4. Fakhr Yasseri AM, Namdari F, Gooran S, et al.: Living versus deceased kidney transplantation: Comparison of complications. Urologia. 2021; 88: 185–189. PubMed Abstract | Publisher Full Text
5. Wilson CH, Sanni A, Rix DA, et al.: Laparoscopic versus open nephrectomy for live kidney donors. Cochrane Database Syst. Rev. 2011;Cd006124. Publisher Full Text
6. Ozturk SA, Yuksel Y, Erbis H, et al.: Laparoscopic Live Donor Nephrectomy: Experience of High-Volume Center with 2,477 Cases. Urol. Int. 2021; 105: 100–107. PubMed Abstract | Publisher Full Text
7. Jacobs SC, Cho E, Dunkin BJ, et al.: Laparoscopic live donor nephrectomy: the University of Maryland 3-year experience. J. Urol. 2000; 164: 1494–1499. PubMed Abstract | Publisher Full Text
8. Dols LFC, Kok NFM, Ijzermans JNM: Live donor nephrectomy: a review of evidence for surgical techniques. Transpl. Int. 2010; 23: 121–130. Publisher Full Text
9. Takagi K, Kimenai H, Terkivatan T, et al.: Learning curves of minimally invasive donor nephrectomy in a high-volume center: A cohort study of 1895 consecutive living donors. Int. J. Surg. 2021; 86: 7–12. Publisher Full Text
10. He B, Bremner A, Han Y, et al.: Determining the Superior Technique for Living-donor Nephrectomy: the Laparoscopic Intraperitoneal Versus the Retroperitoneoscopic Approach. Exp. Clin. Transplant. 2016; 14: 129–138. PubMed Abstract
11. Van der Merwe A, Heyns CF: Retroperitoneoscopic live donor nephrectomy: review of the first 50 cases at Tygerberg Hospital, Cape Town, South Africa. S. Afr. J. Surg. 2014; 52: 53–56. PubMed Abstract | Publisher Full Text
12. Kohei N, Kazuya O, Hirai T, et al.: Retroperitoneoscopic living donor nephrectomy: experience of 425 cases at a single center. J. Endourol. 2010; 24: 1783–1787. Publisher Full Text
13. Tanabe K, Miyamoto N, Ishida H, et al.: Retroperitoneoscopic live donor nephrectomy (RPLDN): establishment and initial experience of RPLDN at a single center. Am. J. Transplant. 2005; 5: 739–745. Publisher Full Text
14. Valsamis EM, Chouari T, O’Dowd-Booth C, et al.: Learning curves in surgery: variables, analysis and applications. Postgrad. Med. J. 2018; 94: 525–530. PubMed Abstract | Publisher Full Text
15. Chin EH, Hazzan D, Herron DM, et al.: Laparoscopic donor nephrectomy: intraoperative safety, immediate morbidity, and delayed complications with 500 cases. Surg. Endosc. 2007; 21: 521–526. Publisher Full Text
16. Wadström J: The Higher Rates of Ileus, Readmission and Hernia After Laparoscopic Donor Nephrectomy Reported Can Be Mitigated by Using a Retroperitoneal Approach Via a Pfannenstiel Incision. Transplantation. 2016; 100: e104. PubMed Abstract | Publisher Full Text
17. IBM Corp.: IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp; Released 2011.
18. Park JS, Ahn HK, Na J, et al.: Cumulative sum analysis of learning curve for video-assisted mini-laparotomy partial nephrectomy in renal cell carcinoma. Medicine (Baltimore). 2019; 98: e15367. PubMed Abstract | Publisher Full Text | Free Full Text
19. Flowers JL, Jacobs S, Cho E, et al.: Comparison of open and laparoscopic live donor nephrectomy. Ann. Surg. 1997; 226: 483–490. PubMed Abstract | Publisher Full Text | Free Full Text
20. Ng ZQ, Musk G, Rea A, et al.: Transition from laparoscopic to retroperitoneoscopic approach for live donor nephrectomy. Surg. Endosc. 2018; 32: 2793–2799. PubMed Abstract | Publisher Full Text
21. Tay WK, Kesavan A, Goh YSB, et al.: Right Living Donor Nephrectomies: Retroperitoneoscopic vs Laparoscopic Transperitoneal Approach. Transplant. Proc. 2018; 50: 2333–2337. Publisher Full Text
22. Ruszat R, Wyler SF, Wolff T, et al.: Reluctance over right-sided retroperitoneoscopic living donor nephrectomy: justified or not? Transplant. Proc. 2007; 39: 1381–1385. Publisher Full Text
23. Sulser T, Gürke L, Langer I, et al.: Retroperitoneoscopic Living-Donor Nephrectomy: First Clinical Experiences in 19 Operations. J. Endourol. 2004; 18: 257–262. PubMed Abstract | Publisher Full Text
24. van der Merwe A , Ebinger Mundorf NN, van Heerden H , et al.: Evaluating the differences in the early laparoscopic donor nephrectomy learning curves of a Swiss high volume transplant program and a South African low volume transplant program after knowledge transfer. Afr. J. Urol. 2021; 27: 119. Publisher Full Text
25. Pusic MV, Kessler D, Szyld D, et al.: Experience curves as an organizing framework for deliberate practice in emergency medicine learning. Acad. Emerg. Med. 2012; 19: 1476–1480. PubMed Abstract | Publisher Full Text
26. Pal BC, Modi PR, Rizvi SJ, et al.: The Learning Curve of Pure Retroperitoneoscopic Donor Nephrectomy. Int. J. Organ Transplant. Med. 2017; 8: 180–185. PubMed Abstract
27. Nakajima I, Iwadoh K, Koyama I, et al.: Nine-yr experience of 700 hand-assisted laparoscopic donor nephrectomies in Japan. Clin. Transpl. 2012; 26: 797–807. PubMed Abstract | Publisher Full Text
28. Zhang XM, Wang Z, Liang JW, et al.: Seniors have a better learning curve for laparoscopic colorectal cancer resection. Asian Pac. J. Cancer Prev. 2014; 15: 5395–5399. PubMed Abstract | Publisher Full Text
29. Takagi K, Kimenai HJAN, Terkivatan T, et al.: A novel difficulty grading system for laparoscopic living donor nephrectomy. Surg. Endosc. 2021; 35: 2889–2895. PubMed Abstract | Publisher Full Text | Free Full Text
30. Schwartz FR, Shaw BI, Lerebours R, et al.: Correlation of preoperative imaging characteristics with donor outcomes and operative difficulty in laparoscopic donor nephrectomy. American Journal of Transplantation: Official Journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2020; 20: 752–760. PubMed Abstract | Publisher Full Text | Free Full Text
31. Wahyudi I, et al.: Transition from transperitoneal to retroperitoneal approach in laparoscopic living donor nephrectomy: Team-based and individual learning curve: A cross-sectional study, Dryad. Dataset. 2022. Publisher Full Text

Comments on this article Comments (0)

Version 1

VERSION 1 PUBLISHED 04 May 2023

Author details Author details

¹ Department of Urology, University of Indonesia, Jakarta, DKI Jakarta, 10430, Indonesia

Irfan Wahyudi
Roles: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Validation, Visualization, Writing – Original Draft Preparation, Writing – Review & Editing

Ilham Azka Adriansyah
Roles: Conceptualization, Data Curation, Formal Analysis, Investigation, Methodology, Project Administration, Resources, Software, Validation, Writing – Original Draft Preparation, Writing – Review & Editing

Kevin Yonathan
Roles: Conceptualization, Data Curation, Methodology, Project Administration, Resources, Writing – Original Draft Preparation, Writing – Review & Editing

Fina Widia
Roles: Conceptualization, Formal Analysis, Resources, Validation, Writing – Review & Editing

Agus Rizal A Hamid
Roles: Conceptualization, Formal Analysis, Resources, Writing – Review & Editing

Chaidir Arif Mochtar
Roles: Conceptualization, Investigation, Methodology, Resources, Writing – Review & Editing

Competing interests

No competing interests were disclosed.

Grant information

The funding for this study was partially fulfilled by Universitas Indonesia with International Indexed Publication Grant Program (PUTI) [grant number NKB-1235/UN2.RST/HKP.05.00/2022]

Article Versions (1)

version 1

Published: 04 May 2023, 12:464

https://doi.org/10.12688/f1000research.129479.1

Copyright

© 2023 Wahyudi I et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Download

Export To

metrics

	Views	Downloads
F1000Research	-	-
PubMed Central Data from PMC are received and updated monthly.	-	-

Citations

0

SEE MORE DETAILS

CITE

how to cite this article

Wahyudi I, Adriansyah IA, Yonathan K et al. Transition from transperitoneal to retroperitoneal approach in laparoscopic living donor nephrectomy: team-based and individual learning curve: a cross-sectional study [version 1; peer review: 2 approved with reservations]. F1000Research 2023, 12:464 (https://doi.org/10.12688/f1000research.129479.1)

NOTE: If applicable, it is important to ensure the information in square brackets after the title is included in all citations of this article.

track

receive updates on this article

Track an article to receive email alerts on any updates to this article.

Open Peer Review

Version 1

VERSION 1

PUBLISHED 04 May 2023

Views

6

Reviewer Report 12 Oct 2023

Luis Garcia-Covarrubias, Surgery, Hospital de Especialidades Centro Medico Nacional Siglo XXI, Mexico City, Mexico City, Mexico

Approved with Reservations

https://doi.org/10.5256/f1000research.142165.r196411

1. Of the references, only 30% are 5 years old or less, recommending that at least 50% of the references be updated.

2. With respect to the design and in order to allow its reproducibility, I suggest ... Continue reading

1. Of the references, only 30% are 5 years old or less, recommending that at least 50% of the references be updated.

2. With respect to the design and in order to allow its reproducibility, I suggest being explicit in the definitions, as well as in the inclusion and exclusion criteria and performing a sample size calculation based on Cohen's D obtained from previous studies.

I would suggest including the Clavien scale to compare complications or other variables, not just time such as hemorrhage, ischemia time, and whether or not the graft suffered any damage, for example.

3. Mention the limitations of the study before reaching the conclusions, as it is a retrospective study and is limited by the indication for nephrectomy (right or left) and the assignment of surgeons to the cases, which is not commented on.

Furthermore, regardless of whether it was transperitoneal or retroperitoneal, the surgeons had extensive experience in laparoscopic surgery.

Is the work clearly and accurately presented and does it cite the current literature?

Partly
Is the study design appropriate and is the work technically sound?

Partly
Are sufficient details of methods and analysis provided to allow replication by others?

No
If applicable, is the statistical analysis and its interpretation appropriate?

Partly
Are all the source data underlying the results available to ensure full reproducibility?

Yes
Are the conclusions drawn adequately supported by the results?

Partly

Competing Interests: No competing interests were disclosed.

Reviewer Expertise: Methodology , surgical techniques

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.

CITE

Report a concern

Respond or Comment

Views

13

Reviewer Report 29 Jun 2023

Mustafa Suat Bolat, Department of Urology, Atilim University, Ankara, Ankara, Turkey

Approved with Reservations

https://doi.org/10.5256/f1000research.142165.r178114

Abstract
Background

The authors state that the transition process from transperitoneal to retroperitoneal LLDN is important to ensure the best outcome for the patients. I wonder if there is a transition process in real. According

Abstract
Background

The authors state that the transition process from transperitoneal to retroperitoneal LLDN is important to ensure the best outcome for the patients. I wonder if there is a transition process in real. According to their experience and educational program, surgeons use their individual techniques. Therefore they only can state that they decided to convert their technique to Retro. Otherwise, it could be misunderstood that nephrectomy should primarily be managed by transperitoneal and it might be converted to retro.

Methods

How did the authors identify Phase 1, 2 and 3?

Introduction

Second paragraph: Preferentially, l advise the authors to cite paper¹. This citation is about to gain experience of laparoscopy. Thus it may improve quality of the manuscript. If authors read it, they will find data supporting their hypothesis.
Sixth Paragraph: What were the time period for three centers? Were the authors observer or fellow?

Discussion

In second paragraph, CUSUM analysis should be given in detail. The authors should remember that many readers might not know about CUSUM analysis.
Fifth paragraph - What is the reason for higher procedure experience need for team-based surgery compared to individual one? Please support it in the light of literature.
Last paragraph - I supposed this paper should be a prospective one?

Is the work clearly and accurately presented and does it cite the current literature?

Yes
Is the study design appropriate and is the work technically sound?

Yes
Are sufficient details of methods and analysis provided to allow replication by others?

Yes
If applicable, is the statistical analysis and its interpretation appropriate?

I cannot comment. A qualified statistician is required.
Are all the source data underlying the results available to ensure full reproducibility?

Yes
Are the conclusions drawn adequately supported by the results?

Yes

References

1. Gozen AS, Gherman V, Akin Y, Bolat MS, et al.: Evaluation of the complications in laparoscopic retroperitoneal radical nephrectomy; An experience of high volume centre.Arch Ital Urol Androl. 2017; 89 (4): 266-271 PubMed Abstract | Publisher Full Text

Competing Interests: No competing interests were disclosed.

Reviewer Expertise: Urology, andrology

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.

CITE

Report a concern

Respond or Comment

Comments on this article Comments (0)

Version 1

VERSION 1 PUBLISHED 04 May 2023

Open Peer Review

Reviewer Status

Reviewer Reports

	Invited Reviewers
	1	2
Version 1 04 May 23	read	read

Mustafa Suat Bolat, Atilim University, Ankara, Turkey
Luis Garcia-Covarrubias, Hospital de Especialidades Centro Medico Nacional Siglo XXI, Mexico City, Mexico

Comments on this article

All Comments(0)

Add a comment

Sign up for content alerts

Browse by related subjects

Back to all reports

Reviewer Report

6 Views

12 Oct 2023 | for Version 1

Luis Garcia-Covarrubias, Surgery, Hospital de Especialidades Centro Medico Nacional Siglo XXI, Mexico City, Mexico City, Mexico

6 Views Cite this report Responses(0)

Approved With Reservations

1. Of the references, only 30% are 5 years old or less, recommending that at least 50% of the references be updated.

2. With respect to the design and in order to allow its reproducibility, I suggest being explicit in the definitions, as well as in the inclusion and exclusion criteria and performing a sample size calculation based on Cohen's D obtained from previous studies.

I would suggest including the Clavien scale to compare complications or other variables, not just time such as hemorrhage, ischemia time, and whether or not the graft suffered any damage, for example.

3. Mention the limitations of the study before reaching the conclusions, as it is a retrospective study and is limited by the indication for nephrectomy (right or left) and the assignment of surgeons to the cases, which is not commented on.

Furthermore, regardless of whether it was transperitoneal or retroperitoneal, the surgeons had extensive experience in laparoscopic surgery.

Is the work clearly and accurately presented and does it cite the current literature?

Partly
Is the study design appropriate and is the work technically sound?

Partly
Are sufficient details of methods and analysis provided to allow replication by others?

No
If applicable, is the statistical analysis and its interpretation appropriate?

Partly
Are all the source data underlying the results available to ensure full reproducibility?

Yes
Are the conclusions drawn adequately supported by the results?

Partly

Competing Interests

No competing interests were disclosed.

Reviewer Expertise

Methodology , surgical techniques

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.

Respond to this report

Responses (0)

Back to all reports

Reviewer Report

13 Views

29 Jun 2023 | for Version 1

Mustafa Suat Bolat, Department of Urology, Atilim University, Ankara, Ankara, Turkey

13 Views Cite this report Responses(0)

Approved With Reservations

Abstract
Background

The authors state that the transition process from transperitoneal to retroperitoneal LLDN is important to ensure the best outcome for the patients. I wonder if there is a transition process in real. According to their experience and educational program, surgeons use their individual techniques. Therefore they only can state that they decided to convert their technique to Retro. Otherwise, it could be misunderstood that nephrectomy should primarily be managed by transperitoneal and it might be converted to retro.

Methods

How did the authors identify Phase 1, 2 and 3?

Introduction

Second paragraph: Preferentially, l advise the authors to cite paper¹. This citation is about to gain experience of laparoscopy. Thus it may improve quality of the manuscript. If authors read it, they will find data supporting their hypothesis.
Sixth Paragraph: What were the time period for three centers? Were the authors observer or fellow?

Discussion

In second paragraph, CUSUM analysis should be given in detail. The authors should remember that many readers might not know about CUSUM analysis.
Fifth paragraph - What is the reason for higher procedure experience need for team-based surgery compared to individual one? Please support it in the light of literature.
Last paragraph - I supposed this paper should be a prospective one?

Is the work clearly and accurately presented and does it cite the current literature?

Yes
Is the study design appropriate and is the work technically sound?

Yes
Are sufficient details of methods and analysis provided to allow replication by others?

Yes
If applicable, is the statistical analysis and its interpretation appropriate?

I cannot comment. A qualified statistician is required.
Are all the source data underlying the results available to ensure full reproducibility?

Yes
Are the conclusions drawn adequately supported by the results?

Yes

References

1. Gozen AS, Gherman V, Akin Y, Bolat MS, et al.: Evaluation of the complications in laparoscopic retroperitoneal radical nephrectomy; An experience of high volume centre.Arch Ital Urol Androl. 2017; 89 (4): 266-271 PubMed Abstract | Publisher Full Text

Competing Interests

No competing interests were disclosed.

Reviewer Expertise

Urology, andrology

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.

Respond to this report

Responses (0)

[1] 1. Lee L-Y, Pham TA, Melcher ML: Living Kidney Donation: Strategies to Increase the Donor Pool. Surg. Clin. N. Am. 2019; 99: 37–47. PubMed Abstract | Publisher Full Text

[2] 2. Tonelli M, Wiebe N, Knoll G, et al.: Systematic Review: Kidney Transplantation Compared With Dialysis in Clinically Relevant Outcomes. Am. J. Transplant. 2011; 11: 2093–2109. Publisher Full Text

[3] 3. Gjertson DW, Cecka JM: Living unrelated donor kidney transplantation. Kidney Int. 2000; 58: 491–499. Publisher Full Text

[4] 4. Fakhr Yasseri AM, Namdari F, Gooran S, et al.: Living versus deceased kidney transplantation: Comparison of complications. Urologia. 2021; 88: 185–189. PubMed Abstract | Publisher Full Text

[5] 5. Wilson CH, Sanni A, Rix DA, et al.: Laparoscopic versus open nephrectomy for live kidney donors. Cochrane Database Syst. Rev. 2011;Cd006124. Publisher Full Text

[6] 6. Ozturk SA, Yuksel Y, Erbis H, et al.: Laparoscopic Live Donor Nephrectomy: Experience of High-Volume Center with 2,477 Cases. Urol. Int. 2021; 105: 100–107. PubMed Abstract | Publisher Full Text

[7] 7. Jacobs SC, Cho E, Dunkin BJ, et al.: Laparoscopic live donor nephrectomy: the University of Maryland 3-year experience. J. Urol. 2000; 164: 1494–1499. PubMed Abstract | Publisher Full Text

[8] 8. Dols LFC, Kok NFM, Ijzermans JNM: Live donor nephrectomy: a review of evidence for surgical techniques. Transpl. Int. 2010; 23: 121–130. Publisher Full Text

[9] 9. Takagi K, Kimenai H, Terkivatan T, et al.: Learning curves of minimally invasive donor nephrectomy in a high-volume center: A cohort study of 1895 consecutive living donors. Int. J. Surg. 2021; 86: 7–12. Publisher Full Text

[10] 10. He B, Bremner A, Han Y, et al.: Determining the Superior Technique for Living-donor Nephrectomy: the Laparoscopic Intraperitoneal Versus the Retroperitoneoscopic Approach. Exp. Clin. Transplant. 2016; 14: 129–138. PubMed Abstract

[11] 11. Van der Merwe A, Heyns CF: Retroperitoneoscopic live donor nephrectomy: review of the first 50 cases at Tygerberg Hospital, Cape Town, South Africa. S. Afr. J. Surg. 2014; 52: 53–56. PubMed Abstract | Publisher Full Text

[12] 12. Kohei N, Kazuya O, Hirai T, et al.: Retroperitoneoscopic living donor nephrectomy: experience of 425 cases at a single center. J. Endourol. 2010; 24: 1783–1787. Publisher Full Text

[13] 13. Tanabe K, Miyamoto N, Ishida H, et al.: Retroperitoneoscopic live donor nephrectomy (RPLDN): establishment and initial experience of RPLDN at a single center. Am. J. Transplant. 2005; 5: 739–745. Publisher Full Text

[14] 14. Valsamis EM, Chouari T, O’Dowd-Booth C, et al.: Learning curves in surgery: variables, analysis and applications. Postgrad. Med. J. 2018; 94: 525–530. PubMed Abstract | Publisher Full Text

[15] 15. Chin EH, Hazzan D, Herron DM, et al.: Laparoscopic donor nephrectomy: intraoperative safety, immediate morbidity, and delayed complications with 500 cases. Surg. Endosc. 2007; 21: 521–526. Publisher Full Text

[16] 16. Wadström J: The Higher Rates of Ileus, Readmission and Hernia After Laparoscopic Donor Nephrectomy Reported Can Be Mitigated by Using a Retroperitoneal Approach Via a Pfannenstiel Incision. Transplantation. 2016; 100: e104. PubMed Abstract | Publisher Full Text

[17] 17. IBM Corp.: IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp; Released 2011.

[18] 18. Park JS, Ahn HK, Na J, et al.: Cumulative sum analysis of learning curve for video-assisted mini-laparotomy partial nephrectomy in renal cell carcinoma. Medicine (Baltimore). 2019; 98: e15367. PubMed Abstract | Publisher Full Text | Free Full Text

[19] 19. Flowers JL, Jacobs S, Cho E, et al.: Comparison of open and laparoscopic live donor nephrectomy. Ann. Surg. 1997; 226: 483–490. PubMed Abstract | Publisher Full Text | Free Full Text

[20] 20. Ng ZQ, Musk G, Rea A, et al.: Transition from laparoscopic to retroperitoneoscopic approach for live donor nephrectomy. Surg. Endosc. 2018; 32: 2793–2799. PubMed Abstract | Publisher Full Text

[21] 21. Tay WK, Kesavan A, Goh YSB, et al.: Right Living Donor Nephrectomies: Retroperitoneoscopic vs Laparoscopic Transperitoneal Approach. Transplant. Proc. 2018; 50: 2333–2337. Publisher Full Text

[22] 22. Ruszat R, Wyler SF, Wolff T, et al.: Reluctance over right-sided retroperitoneoscopic living donor nephrectomy: justified or not? Transplant. Proc. 2007; 39: 1381–1385. Publisher Full Text

[23] 23. Sulser T, Gürke L, Langer I, et al.: Retroperitoneoscopic Living-Donor Nephrectomy: First Clinical Experiences in 19 Operations. J. Endourol. 2004; 18: 257–262. PubMed Abstract | Publisher Full Text

[24] 24. van der Merwe A , Ebinger Mundorf NN, van Heerden H , et al.: Evaluating the differences in the early laparoscopic donor nephrectomy learning curves of a Swiss high volume transplant program and a South African low volume transplant program after knowledge transfer. Afr. J. Urol. 2021; 27: 119. Publisher Full Text

[25] 25. Pusic MV, Kessler D, Szyld D, et al.: Experience curves as an organizing framework for deliberate practice in emergency medicine learning. Acad. Emerg. Med. 2012; 19: 1476–1480. PubMed Abstract | Publisher Full Text

[26] 26. Pal BC, Modi PR, Rizvi SJ, et al.: The Learning Curve of Pure Retroperitoneoscopic Donor Nephrectomy. Int. J. Organ Transplant. Med. 2017; 8: 180–185. PubMed Abstract

[27] 27. Nakajima I, Iwadoh K, Koyama I, et al.: Nine-yr experience of 700 hand-assisted laparoscopic donor nephrectomies in Japan. Clin. Transpl. 2012; 26: 797–807. PubMed Abstract | Publisher Full Text

[28] 28. Zhang XM, Wang Z, Liang JW, et al.: Seniors have a better learning curve for laparoscopic colorectal cancer resection. Asian Pac. J. Cancer Prev. 2014; 15: 5395–5399. PubMed Abstract | Publisher Full Text

[29] 29. Takagi K, Kimenai HJAN, Terkivatan T, et al.: A novel difficulty grading system for laparoscopic living donor nephrectomy. Surg. Endosc. 2021; 35: 2889–2895. PubMed Abstract | Publisher Full Text | Free Full Text

[30] 30. Schwartz FR, Shaw BI, Lerebours R, et al.: Correlation of preoperative imaging characteristics with donor outcomes and operative difficulty in laparoscopic donor nephrectomy. American Journal of Transplantation: Official Journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2020; 20: 752–760. PubMed Abstract | Publisher Full Text | Free Full Text

[31] 31. Wahyudi I, et al.: Transition from transperitoneal to retroperitoneal approach in laparoscopic living donor nephrectomy: Team-based and individual learning curve: A cross-sectional study, Dryad. Dataset. 2022. Publisher Full Text

Transition from transperitoneal to retroperitoneal approach in laparoscopic living donor nephrectomy: team-based and individual learning curve: a cross-sectional study

Abstract

Keywords

Introduction

Methods

Operative technique

Operators

Statistical analysis

Results

Individual learning curve of retroperitoneal LLDN operator

Figure 1. Cumulative SUM (CUSUM) for operation time of Laparoscopic Living Donor Nephrectomy (LLDN).

Team-based learning curve of retroperitoneal LLDN operator

Figure 2. Team-based learning curve of retroperitoneal Laparoscopic Living Donor Nephrectomy (LLDN) Operator.

Clinical outcome compared to experience

Table 1. Clinical outcome of donors in each phase.

Discussion

Conclusions

Authors’ contributions

Ethics approval and consent to participate

Data availability

Underlying data

Extended data

Acknowledgments

References

Comments on this article Comments (0)

Open Peer Review

Comments on this article Comments (0)

Open Peer Review

Reviewer Status

Reviewer Reports

Comments on this article

Browse by related subjects

Competing Interests Policy

Stay Updated