Comparison between staged laparoscopic technique in children with high intra-abdominal undescended testis: a systematic review and meta-analysis

Introduction

Cryptorchidism is one of the most frequent congenital deformities of male neonates, also known as undescended testis (UDT). The incidence varies according to gestational age, affecting 1.0–4.6% of full-term infants and 1.1–45% of preterm infants.¹ Undescended testis (UDT), also known as cryptorchidism, is a condition in which the testicles are not ordinarily found at the bottom of the scrotum.² For clinical reasons, UDT is usually classified between palpable and non-palpable. The management of UDT is determined by the location and presence of the testes. About 20% of UDT are non-palpable, and about 10-50% of these impalpable testes either vanished or atrophied.³

UDT diagnosis is established by clinical examination, and its diagnosis is supplemented by imaging techniques, for example, B-ultrasound and magnetic resonance imaging; however, laparoscopic exploration remains the gold standard for unpalpable UDT.^4–6 Undescended intra-abdominal testis (IAT) is a type of non-palpable UDT that occur in 40% of laparoscopy findings.¹ Short gonadal arteries typically make it difficult to successfully mobilize the testis to the scrotum without strain, making IAT a technical surgical challenge for pediatric urologists.⁷ Usually, a High IAT that lies more than 2 cm superior to the internal inguinal ring will probably not reach the scrotum and requires a staged procedure.¹

The most effective and safest procedure for highly impalpable IAT is laparoscopic staged orchiopexy.⁸ Several techniques have been described for laparoscopic orchidopexy. After spermatic vascular transection, single-stage testicular descent fixing was carried out, as Fowler and Stephens first described in 1959.⁹ The Fowler-Stephens laparoscopic orchiopexy (FSLO) procedure describes proximal cutting and transection of the testicular vessels with preservation of the collateral arterial blood supply through the deferential artery and cremasteric vessels to gain sufficient length, which helps mobilize and relocate the testis into the scrotum.^1,5,6,9 Due to the nature of these procedures, the testicles may be in jeopardy of hypotrophy or atrophy if the collateral blood supply is lacking.¹ In one-stage FSLO, the testicular survival rate ranges between 50 and 65%, while in second-stage FSLO, it is 90%.¹

Shehata et al.¹⁰ proposed a preliminary study with the preservation of a vascular technique called SLTO (staged laparoscopic traction orchiopexy) to overcome these problems. This technique does not divide the testicular vessels, which spares the major testicular blood supply. The strategy is based on tissue expansion of the testicular vasculature to expand the distended veins to the opposing anterosuperior part of the iliac spine without tearing them apart.¹⁰

However, it is still debated whether SLTO techniques have more advantages than FSLO.¹¹ Currently, few studies compare head-to-head measures between FSLO and SLTO with small sample sizes. The best approach and schedule for the treatment of undescended testes have been a matter of debate for decades,¹² and recent studies showed sub-optimal results in managing high IAT. In the scientific community, coming to a consensus is difficult, particularly in the medical domain, where one needs to have a long enough follow-up in a randomized controlled study with a big enough size and standardized patient groups.¹¹ In this study, we executed a systematic review and meta-analysis to compare the staged laparoscopic FSLO and SLTO outcomes in patients with intra-abdominal testes.

Methods

Results

Literature search

After article screening and applying exclusion criteria, 212 articles were identified from the three databases. A total of 147 studies were examined after duplicates were eliminated. Sixteen of these papers with reviewed full texts were determined to be relevant based on their titles and abstracts. A total of five papers were finally included in the qualitative and quantitative analysis (Figure 1).

Figure 1. Literature search strategy according to PRISMA guideline.

Primary outcome

Testicular descend

The testicular ascend success rate for both FSLO and STLO was reported in all five studies. The testicular growth rate between the STLO and FSLO groups had low heterogeneity and was not statistically significant, according to a meta-analysis of these trials (RR: 1.08; 95% CI: 0.96 – 1.23; p<0.20) (Figure 2).

Figure 2. Forrest plot of testicular descend.

Testicular atrophy

The testicular atrophy rate for both FSLO and STLO was recorded in all five studies. The testicular atrophy rate between STLO and FSLO groups had low heterogenicity and was not statiscally significant, according to a meta-analysis of these trials (RR: 0.45; 95% CI: 0.19 – 1.09; p<0.08, I²: 0%) (Figure 3).

Figure 3. Forest plot of testicular atrophy.

Secondary outcome

Operation time in the first stage

The FSLO group had significantly shorter operation times (Mean Difference: 9.31; 95% CI: 7.08 – 11.55; p<0.0001), and there was considerable heterogeneity, according to a meta-analysis of these studies (Figure 4).

Figure 4. Forest plot of operation time in first stage.

Operation time in the second stage

All four studies reported the mean second-stage operation time of both FSLO and STLO. The SLTO group had a statistically significant decreased operation time (Mean Difference: -4.05; 95% CI: -7.99 – 0.12; p<0.04), and there was considerable heterogeneity, according to a meta-analysis of these investigations (Figure 5).

Figure 5. Forest plot of operation time in the second stage.

Evaluation for publication bias

Due to the small number of research, a funnel plot was not generated. Tests for funnel plot asymmetry should generally only be conducted when there are at least ten study groups. The power of the test is insufficient to distinguish between chance and actual asymmetry because of the small number of included studies examining the results of the staged laparoscopic FSLO and SLTO in patients with intra abdominal testes.¹³

Discussion

Pediatric surgeons continue to face many difficulties when doing surgery for the abdominal testis. Although numerous surgical techniques have been documented to address this issue, none have emerged as the clinical paradigm’s gold standard. The lack of an optimal surgical method or imaging technologies and an inadequate understanding of the interactions between the genetic, physiological, and hormonal pathways involved in testicular descent are the main causes of the unavailability of an international agreement on a management plan.^14–19 The most typical method of exploring unpalpable testicles is by minimally invasive laparoscopy. An orchiopexy, or the surgical transfer of the testis into the scrotum, can be carried out if the testicle is visible. The absent or vanishing testis is diagnosed if the spermatic arteries have blind endings. In this way, both the diagnosis and treatment can be performed in a single setting by laparoscopic.¹⁴

There is still no consensus regarding the criteria for high IAT; however, the latest Ains shams classification type 4 (Figure 2) can be used to categorize high IAT for similar criteria with several studies that define high intra-abdominal testis if the testis is more than 2 cm from ipsilateral side of the inner ring.^19–21 These studies also have taught us that the IAT less than 2 cm away from the inner ring can be lowered and attached securely to the scrotum. Other studies like Bawazir and Bagga et al. defined high intra-abdominal testis if the testis is >1 cm from the ipsilateral inner ring.^15,16 Whereas Esposito et al.¹⁸ and Valeska et al.¹⁷ claimed that the standard distance is 3 cm. However, Agrawal et al. believed that the appropriate distance is 2.5 cm.¹⁹ Multi-center studies with large samples and long-term follow-up are needed for selection criteria that could be properly used as a consensus.²⁰

Since the advancement of minimally invasive surgery, there have been several methods for laparoscopic procedures in managing IAT. In this study, we compared two surgical methods (SLTO and FSLO) for the management of High IAT. As an alternative, testes can be repositioned in the scrotum and the distal testicular vessels (TVs) and can be anastomosed with the inferior epigastric vessels through the division of the proximal TVs. This procedure is known as microvascular testicular auto-transplantation.^23,25,26 Unfortunately, there are several issues in the supporting data for this technique.^23–26 It is labor-intensive (median time: 4.5 hours), time-consuming, and has a variable success rate (84–97%).²⁵

After spermatic vascular transection, single-stage testicular descent fixing was carried out, as Fowler and Stephens first described in 1959. Since then, though with only unsatisfactory outcomes, Fowler-Stephens staged orchidopexy has dominated surgical procedures.⁹ A single or two stages procedure to lower the testis into the scrotum is necessary and is dependent on collateral blood flow from the deferential and external spermatic arteries. To provide more direct access to the scrotum, the testis can also be passed medially to the inferior epigastric arteries via the Prentiss maneuver, which involves opening the transversalis fascia. However, this approach has been linked to testicular atrophy. A phased surgery has considerably decreased the rate of testicular atrophy, which is quite common in the initial stages of the F-S technique.²⁷ By using the test for testicular ischemia, prevention has been made to ensure testicular collateral circulation.²⁸ Testicular ischemia test was done by blocking the blood vessels of the spermatic cord with some silk thread and holding them for 10 minutes. When making a knot, it should be assured that the knot can be loosened when necessary, and then see if there are visible changes in the blood supply of testicles before and after the test. It is considered appropriate for F-S surgery if there is no visible ischemic change in the testis following spermatic vascular blockage. It means that the collateral blood supply of the testicles is plentiful, and the gubernaculum’s blood supply is adequate.²⁸ However, since the impact of the testicular ischemia test on the phenomena of testicular atrophy has not been researched, everything depends heavily on the surgeon’s practices.²⁰

Shehata proposed a pilot research with encouraging findings from gradually controlled traction facilitated by laparoscopic surgery in 2008.¹⁰ This method was revised and reposted later in 2016, confirming its efficacy and safety.²¹ Similar to the Fowler Stephen group, this procedure used a comparable anesthetic technique, operation posture, and trocar position for the puncture.⁹ An inch superior and medial to the contralateral side of the anterior superior iliac spine (ASIS) in the abdomen, the testis is secured with a round needle to the fixation location. After three months, a second-stage laparoscopic-assisted orchiopexy was scheduled. The testicles are lowered to the scrotum and secured by incision from the scrotum on the affected side in the second stage of both surgical procedures, which are both assisted by laparoscopy.²⁴ Because the internal spermatic artery, vas deferens artery, and veins were intact throughout the procedure, the Shehata approach efficiently secured the blood supply of the testis. The spermatic cord is pushed backward and downward by the gut, and the testis is stabilized in the rightful location during the first stage. The primary advantage of this approach is the ability to progressively enlarge the spermatic cord blood vessels without causing testicular ischemia, which is achieved by either chronic intestinal compression or continual respiratory movement.²⁴ This may be explained by the SLTO technique of non-transection of the testicular vasculature and the vascular pedicle’s progressive, gentle elongation.

The successful outcome of the orchiopexy is the study’s main objective. The right testicular location in the scrotum without atrophy or ascent was considered successful. A testis in the bottom or middle of the scrotal cavity without tension was referred to as being in the scrotal position. A testis located at the neck of the scrotum was not considered a successful example since it did not meet the criteria of the scrotal location. A testicle relocation outside the scrotal cavity is referred to as testicular ascension. Based on physical examination by clinicians and the data from ultrasonography measurements, postoperative testicular atrophy was defined as the presence of a nubbin or more than 50% testicular volume loss or a postoperative testicular volume of 25% of the volume of the contralateral testis, with no detectable blood flow as evidenced by color Doppler ultrasound in comparison to the normal contralateral side.

According to our research, both groups’ testicular descent rates are equivalent. Regarding the fixed position of the scrotum in the case of High IAT, both staged laparoscopic methods showed a similar success rate.²⁷ However, because the testicular artery was disrupted during this treatment, the FSLO group has a greater rate of testicular atrophy. We believe that keeping the testicular arteries intact may result in superior outcomes and reduce the chance of testicular atrophy. When excessive tension was not applied from the beginning in the case of testicular veins that are too short, the testicular ascent would occur and could not accomplish adequate elongation necessary for free testis mobilization into the scrotum.²² However, according to Aljubaibi et al., the success rate of the SLTO group was 93% for <2 cm; 78% for 2-4 cm; nil for >4 cm, respectively. Hence, they advocated the FSLO procedure be conducted to testes more than 4 cm from the IIR.²³

The secondary outcomes of our study are mean operation time between the first and second stages of both procedures. Although it is shown that the first stage favoured the FSLO procedure, the limited number of the study showed high heterogenicity. Further comparisons are needed to conclude since SLTO is still a new technique, and a learning period is still needed for surgeons to adapt to this technique. Testicular ischemia test in FSLO also can be considered for extra 10 minutes of procedure, making both results similar is conducted. According to our review, FSLO and SLTO shared similar results in the second procedure. This may contribute to similar procedures in both techniques. This outcome is crucial for surgeons to choose which technique based on their knowledge and the comorbidities of the patient as both technique are not significantly superior in terms of testicular descend and testicular atrophy.

The success rate of the SLTO procedure for aged less than two years or distances less than 4 cm was higher than FSLO. The limitation of Shehata is that when it is applied on patients over two years, and the distance is over 4 cm, the failure rate of the Shehata increases as older age results in a longer pull distance. To measure the length gain indirectly, Shehata et al., introduced a Meryland and allowed it to extend the testicular pedicle under its weight. They then measured the length from the pedicle to the anterior abdominal wall in the midline and found a mean gain of 4.7 cm.²¹ But Aljunaibi et al. found a mean gain of 3.4 cm using a more objective and trustworthy method because it is connected to and evaluated against the scrotal distance.²³ However recent study by Valeska et al.¹⁷ concluded that the age of the patient did not have any influence on the final testicular position in their study.

Another benefit was that SLTO only required three months to go from stage one to stage two, while FSLO took at least six months. Following Fowler Stephen’s recommendation, Shehata and his coauthors established a 12-week gap between the two stages. This gap is essential to facilitate neovascularization between the artery of the vas and the distal testicular arteries, which provides an alternative blood supply to the testis. Still, a recent study by Aljunaibi showed that traction orchiopexy should adhere to the same time intervals as other traction and stretching procedures used in other pathologies, such as tissue expanders and long-gap esophageal atresia.^9,21,23 Both approaches follow a 1-week break; then, a reevaluation was done to see if further stretching to a new stretch point is necessary after tissue remodeling has gone into effect and the preceding stretch point is no longer effective.²³

A shorter time between the two stages reduces the risk of internal hernia or suture slippage. It also lessens the probability that the testicles would adhere to the abdominal wall and helps to mobilize them if they do so because they are fibrinous adhesions rather than fibrous ones. By the time of follow-up, all patients had achieved the previously defined success. None of them experienced a hernia or a wound infection within proximity of the port.²³

The small sample size and the excessive heterogeneities in the mean operation time variables are the study’s drawbacks. Consequently, the writers believe that a more extensive study should be carried out in urology centers with a larger sample size and with surgeons who specialise in both FSLO and SLTO in the management of High IAT. Because the method was published in 2016, it is also impossible to know the fertility results for the SLTO group. So, at this time, it is impossible to compare the long-term outcomes of the two types of surgery.

In conclusion, the SLTO showed a similar result to the FSLO technique in terms of testicular descent and testicular atrophy. There is a difference in mean operation time in the first stage; however, further study is needed to conclude. The mean operation time in the second stage is shorter. Therefore, it could be inferred that the SLTO technique has superiority in terms of complication and waiting time between procedures. Both techniques have their respective advantages and disadvantages; however, we recommend SLTO as the first choice in children with high IAT < 4 cm.