Spigelian Hernia: Diagnostic Challenges And Therapeutic Approaches: Report of Fourteen Clinical Cases

Inclusion and exclusion criteria

We included all patients younger than 18 years of age who underwent surgical repair for Spigelian hernia. We excluded patients with:

Data collection

Epidemiological, clinical, radiological, and therapeutic data were collected using a standardized form. The following parameters were analyzed:

Radiological assessment

Ultrasound examinations were performed using a Philips Affiniti 70 (Philips Healthcare, Netherlands) with a 7.5 MHz linear transducer. Computed tomography (CT) scans were acquired using a Siemens SOMATOM Definition AS (Siemens Healthineers, Germany), with 5-mm axial and coronal slices and intravenous contrast administration (Iopamidol 370 mg/mL, Bracco, Italy). Imaging was interpreted independently by two senior radiologists. Discrepancies were resolved by consensus.

Surgical technique

All procedures were performed under general anesthesia by senior surgeons specialized in abdominal wall repair. Prophylactic intravenous antibiotics (cefazolin 2 g) were administered at induction.

When small bowel resection was required for strangulation, an ileo-ileal anastomosis was performed using a two-layer hand-sewn technique with 3-0 absorbable sutures (Vicryl^®, Ethicon, USA) for the inner layer and 3-0 silk sutures for the outer layer. A closed-suction Redon drain (14 Fr) was used in selected cases with large dissection planes.

Bias control and reproducibility

To minimize bias and variability:

Postoperative follow-up

Patients were evaluated daily during hospitalization, and follow-up was scheduled at 1 month, 3 months, and then annually when feasible. Early complications (wound infection, seroma, hematoma, ileus) and long-term outcomes (recurrence) were recorded.

Statistical analysis

Data were entered and analyzed using Microsoft Excel 2016 (Microsoft, USA). Quantitative variables were expressed as mean ± standard deviation or median (range) for non-normally distributed variables. Qualitative variables were presented as frequencies and percentages.

Incidence

Spigelian hernia is the protrusion of preperitoneal fat, a peritoneal sac, or abdominal organs through a defect in the Spigelian aponeurosis—a fibrous layer situated between the rectus abdominis muscle and the semilunar line. This condition typically manifests in the Spigelian zone, a region of structural vulnerability where the aponeuroses of the transversus abdominis and internal oblique muscles become thinner. ^{1, 2} It is an uncommon type of ventral abdominal wall hernia, accounting for 1 to 2% of all abdominal wall hernias.^3,4

This finding aligns with the results of our study, which reported an average incidence of 1.4 Spigelian hernia repairs per year. According to our data, Spigelian hernias are exceptionally rare, accounting for only 0.28% of all operated abdominal wall hernias in our department.

Clinical background

Spigelian hernia is a rare condition with no clear sex predominance in the literature. In a French series by Guivarch et al., involving 51 patients, the sex ratio was reported as 1.³ Spangen’s series noted a slight female predominance.⁴ In contrast, our Tunisian cohort demonstrated a marked female predominance (sex ratio 0.07), likely attributable to the limited sample size and regional risk factors such as obesity and multiparity—pregnancy being an exclusive female herniogenic factor.

The mean age of onset in our study aligns with Swedish data (~40 years),³ differing from French reports (71 years), ¹ possibly reflecting demographic variations.

Chronic cough, a poorly documented risk factor, emerged as significant in our series (14 cases).

Several predisposing factors have been proposed in the literature.

83.3% of the female patients in our cohort were multiparous (≥2 pregnancies), corroborating findings from Moroccan and Tunisian studies that have established a significant association between multiparity and the development of Spigelian hernias.^5,6

Our study, with a relatively larger series of 14 cases, also supports a strong association between chronic cough—particularly in the context of chronic obstructive pulmonary disease (COPD)—and the development of Spigelian hernia.

Concurrent abdominal wall defects or a history of prior hernia surgery were documented in 28.6% of cases, reflecting findings from previous studies that report frequent associations between Spigelian hernias and other hernia types.^7,8

Clinical findings

Spigelian hernias pose significant diagnostic difficulties due to their unique anatomical location. When small, the hernia remains tightly constrained, making it difficult to palpate. Larger defects or those occurring in a thin abdominal wall may become visible in a standing position.

Clinical symptoms vary, ranging from mild discomfort to sharp pain.

According to studies published by Bouali⁵ and Neto⁶ (2021), Spigelian hernias frequently present at an advanced, complicated stage, with strangulation being a common finding.

These observations align with our findings: the majority of patients (92.8%) reported paroxysmal abdominal pain, while 50% described subocclusive episodes and 28.5% were admitted on an emergency basis for continuous abdominal pain associated with vomiting.

The reliability of physical examination alone remains limited. A palpable mass with a cough impulse is rare and is more likely to be detected when the hernia sac is large and/or the patient is thin.⁹ In two studies published in 2002³ and 2006,¹⁰ Larson et al. found that clinical diagnosis of Spigelian hernia was established in 64% of cases,³ rising to 71% in the series by Malazgirt.¹⁰

These findings are consistent with those of our cohort. Physical examination led to diagnosis in only two patients (14.2%), in whom a mass was palpated along the pararectal line.

Radiologic exploration

Given the limitations of clinical assessment, imaging plays a crucial role in diagnosing Spigelian hernias. While ultrasound is useful for initial evaluation, abdominal computed tomography (CT) remains the gold standard due to its superior sensitivity and ability to assess hernia contents.

Ultrasound enables differentiation between a Spigelian fascial defect and a solid mass with high sensitivity, reported to range between 83% and 100%. ²

In our study, the diagnostic sensitivity was slightly lower than reported in the literature, reaching approximately 64.2%. Ultrasound enabled diagnosis in 9 of the 14 patients: it identified the parietal defect in 8 cases and visualized intra-sac digestive content in 1 case.

Due to the frequent misdiagnosis of Spigelian hernias as lipomas or other abdominal wall pathologies—and the fact that small hernias may not traverse all muscle layers—CT is the preferred diagnostic tool.¹¹ It clearly visualizes the aponeurotic defect at the lateral border of the rectus abdominis muscle, the hernia sac, and—in certain cases—its intra-sac contents. CT is also critical for differential diagnosis in cases of suspected strangulation, helping to exclude tumors, diverticulitis, or acute appendicitis. In our cohort, CT was performed only in emergency case.

Surgical management

Due to the risks of complication, it is recommended a surgical repair for Spigelian hernias. The choice between open and laparoscopic approaches in the surgical management of Spigelian hernias remains a subject of ongoing debate, largely due to the absence of high-level evidence guiding clinical practice.

Several studies have examined the role of laparoscopy in managing lateral ventral hernias, including one of the earliest by Moreno-Egea et al. in 2002. They demonstrated a statistically significant difference between the two approaches, with laparoscopy being associated with reduced postoperative morbidity and shorter hospital stays.⁴ However, these findings were challenged by Clark et al.,¹² who argued that the disadvantages observed with the open approach were largely attributable to anesthetic agents rather than the surgical technique itself.

Although laparoscopy facilitates better visualization of the hernia defect and allows the detection of occult or multiple hernial orifices, its utility may be limited in cases involving large defects. In such scenarios, open repair—particularly with preperitoneal mesh placement—remains a viable and sometimes preferable option.

In our cohort, the majority of patients (13 out of 14, or 92.8%) were treated via an open approach. Only one patient underwent laparoscopic repair, and outcomes were comparable between the two approaches.

In a 2024 study of 43 patients with Spigelian hernia, Clark¹² reported postoperative complications in 36% of cases treated via the open approach, compared to 13% for the laparoscopic group. Moreno-Egea et al. also reported higher long-term recurrence rates with the open approach.⁴

Numerous surgical approaches and repair techniques are available, including open herniorrhaphy or mesh repair (either preperitoneal or preaponeurotic) and, via laparoscopy, simple suture or prosthetic repair using intraperitoneal (IPOM), transabdominal preperitoneal (TAPP), or totally extraperitoneal (TEP) methods.

Although associated with higher recurrence rates, herniorrhaphy remains an option in Spigelian hernia repair, particularly when the hernia neck is narrow (<2 cm).^13,14 Some surgeons still opt for simple sutures in emergency settings. Recent studies evaluating the infection risk of prosthetic repair in strangulated hernias suggest that this risk is not significantly higher than in elective surgery.¹² In our study, nine patients (64.2%) underwent herniorrhaphy. These included the four patients operated on in emergency settings

In contrast to simple suture repair, prosthetic hernioplasty is associated with virtually no recurrences. In the Mayo Clinic series, three recurrences occurred among 75 patients treated with suture repair, while no recurrences were observed in the group that received prosthetic repair—corresponding to recurrence rates of 4% and 0%, respectively.³ Similarly, in a 2002 paper, Moreno-Egea et al. reported no recurrences in 22 patients treated with mesh repair.⁴

With the efficacy of mesh repair firmly established, particularly in terms of recurrence, the current debate focuses on mesh placement. Open repair may involve preperitoneal or preaponeurotic positioning, while laparoscopic repair can use IPOM, TAPP, or TEP techniques. At present, there are no strong recommendations favoring one approach over the others, as each has its advantages and limitations.

In our series, all patients treated via the open approach in non-emergency settings (9 out of 14, or 64.2%) underwent mesh repair. In one case, the mesh was placed in the preperitoneal space; in four others, it was positioned between the internal and external oblique muscles.

Recently, case reports have described successful robotic-assisted repair of Spigelian hernias, with promising preliminary outcomes.^15,16

Table 4 provides a comparative overview of major studies addressing Spigelian hernia repair, focusing on surgical techniques, recurrence rates, and associated complications.

Post operative outcome

Immediate postoperative morbidity following abdominal wall surgery is not negligible. It is mainly due to local wound complications including seroma formation (5-15%), hematomas (3-8%), surgical site infections (2-10%), skin necrosis (1-3%), prosthetic infection (1-5%), enterocutaneous fistula formation (0.5-2%), and postoperative ileus (5-12%). The few randomized studies on Spigelian hernia, including those by the Mayo Clinic and Moreno-Egea, compared open and laparoscopic mesh repair. Both showed a consistent trend favoring the laparoscopic approach, with lower rates of superficial wound complications (1.5% vs. 10.1%) and shorter hospital stays. These differences failed to reach statistical significance in pooled analyses. ^{1, 2}

Long-term outcomes following abdominal wall hernia repair are evaluated through recurrence rates, chronic postoperative pain, and quality of life measures. The few available studies on Spigelian hernia repairs showed that mesh repairs are associated with significantly fewer recurrences compared to simple sutures. In the Mayo Clinic series, only 3 out of 75 sutures led to recurrence (4%), whereas none of the 6 patients who received mesh experienced recurrence. Similarly, in the Moreno-Egea study, no recurrence was reported among 22 mesh repairs. ^{1, 2}

Meta-analytic data from general abdominal wall repairs corroborate these findings, demonstrating equivalent long-term efficacy between open and laparoscopic mesh techniques (3.6% vs 3.4% recurrence, respectively) in a pooled analysis of 526 patients.

Despite these favorable outcomes, some concerns remain about the intraperitoneal placement of mesh due to potential risks such as fistulas, adhesions, or intestinal obstruction. However, a cohort study by Hawn found no significant increase in such complications, even though 5% of meshes had to be partially or completely removed. In our own study, we observed similar results, with a low recurrence rate and no significant rise in complications after intraperitoneal mesh placement. Nonetheless, careful technique selection tailored to the hernia characteristics and surgeon’s expertise remains essential.