Spigelian Hernias: A high volume institutional review

About 100 years after the semilunar line was first described by Adriaan van den Speighel, the first Spigelian hernia was described [1,2]. Since that time, this variety of lateral ventral hernia has been frequently discussed, but infrequently studied. In this edition of Surgery Open Science, the authors from Toronto describe a large retrospective series from their specialty hospital. They clearly illustrate the difference between a Spigelian hernia and an interstitial inguinal hernia, dispel some myths, and add some structure around the patient factors that should lead to consideration of this disease process in the differential diagnosis of pain or other unusual symptoms occurring in the Spigelian belt of the abdominal wall. Spigelian hernias occur across a wide age range, and in this series of elective repairs show a strong male predominance. More than 95 % of these hernias presented as an interstitial type, which reinforces the primary reason that they are so difficult to diagnose on clinical exam alone. While the authors clearly state that surgical approach was not a focus of the current work, the ubiquitous application of an open anterior approach in this series, as well as the variability of mesh reinforcement merits further discussion.

The 2019 Updated Guidelines for Laparoscopic Treatment of Ventral and Incisional Abdominal Wall Hernias recommends that laparoendoscopic mesh repair should be preferred because of lower postoperative morbidity and reduced length of hospital stay [3]. This recommendation is based on low to moderated levels of evidence from the recent literature. Potential benefits of a minimally invasive approach to repair of Spigelian hernias are consistent with benefits of MIS across most operations. These include reduced morbidity rates, decreased pain, and decreased hospital stay. The most widely applied MIS approach is to cover the defect with an intraperitoneal underlay mesh with wide overlap. This approach should ideally include a complete preperitoneal dissection with reduction of incarcerated preperitoneal fat. A robotic assisted laparoscopic approach facilitates additional steps, including achieving primary fascial closure and enables wide mesh overlap in either the preperitoneal or retro muscular spaces. Given the high incidence of the intraparietal type of Spigelian hernia highlighted in the featured manuscript, the minimally invasive approach would be ideal to preserve the intact external oblique, while facilitating fascial reinforcement with permanent synthetic mesh, slowly absorbable synthetic mesh, biologic mesh, or no mesh at all based on shared decision making by the patient and surgeon. While there are no available data to reliably guide us in our decision making around the operative approaches, these hypothetical advantages should be discussed with patients to allow them to make an optimally informed decision that best fits with their goals and their surgeon's skill set.

The case for mesh has been argued for decades for inguinal hernias, but application of mesh to hernias of the ventral abdominal wall is less controversial. The current work reflects an enviable patient population, with median BMI in the range of normal to only slightly overweight. Similarly, only ∼10 % of the patients were smokers. In this healthy population, excellent outcomes can likely be achieved with primary repair alone, however most readers should consider if this represents their patient population before choosing to forgo mesh reinforcement of ventral hernia defects greater than 1-2 cm. As stated above, primary repair can still be affected via an MIS approach when indicated, while facilitating definitive diagnosis and excellent visualization.

Declaration of competing interest

Dr. Ritter has the following COI's that are not related to this work

Applied Medical – Consultant

Boston Scientific – Consultant

Henry M. Jackson Foundation for the Advancement of Military Medicine - Royalties on licensed simulation product