Surgical Technique for Excision of Cesarean-Scar Endometriosis: Approach and Considerations

Introduction

Abdominal-wall endometriosis (AWE) is one of the commonest extrapelvic locations of endometriosis. Cesarean-scar endometriosis (CSE) is the most prevalent form of AWE and is an increasingly recognized condition in which endometrial tissue implants on the surgical scar following a cesarean section. ¹ The prevalence of CSE ranges from 0.03% to 1.08% among women who have cesarean sections. ² CSE typically presents as a palpable tender nodule at the site of the previous cesarean-section scar. The nodule increases in size during menstruation and the patient presents with cyclical tenderness. The symptoms may develop months, or—more typically—years after the cesarean section (on average, 3.6 years). ³

Medical therapy is often ineffective for complete resolution of the lesion.^4,5 Surgical excision is the definitive treatment for CSE and can provide complete resolution of symptoms in up to 90% of cases. This article—with its description of the surgical technique and 2 illustrative cases plus an accompanying video (Supplementary Video S-1; Supplementary data are available online at www.liebertonline.com/GYN) —demonstrates the surgical technique for excising a CSE.

Technique

Patients with CSE require multidisciplinary care with a team of gynecologists specializing in endometriosis care and plastic surgeons.

Preoperative workup includes an abdominal-wall ultrasound along with a magnetic resonance imaging (MRI) scan. The size, location, and margins of the nodule are delineated. The possibility of mesh repair is discussed with the patient.

Often, these modules are not solitary. Preoperative gonadotropin-releasing hormone agonists are not recommended due to the risk of fibrous metaplasia of the lesions.

In Case 1, prior to laparoscopy, the margin of the palpable endometriosis nodule was marked on the abdomen (Fig. 1). Following laparoscopy, the previous Pfannenstiel incision scar was excised and subcutaneous dissection up to the encapsulated endometriosis lesion was performed.

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FIG. 1.

Marking the Palmer's point for laparoscopy and margin of the palpable scar endometriosis nodule prior to excision (Case 1).

Dissection of this lesion identified its involvement with the anterior rectus fascia and rectus muscle; resection was performed with a 1-cm margin around the lesion. The dissection continued up to the preperitoneal fat. The peritoneum was not involved and was protected throughout the procedure. En bloc removal of the lesion was performed, and the excised tissue was sent for histopathology. Hemostasis was monitored carefully throughout the procedure.

A washout was performed with 0.9% sodium chloride and betadine. Plication of the rectus muscles was performed with a Vicryl suture in an interrupted fashion. To reduce the risk of hematoma and seroma formation, a size-10 redivac drain was placed on top of the muscle and fixed with a 2-0 silk suture. The anterior rectus fascia was closed with a nonabsorbable 1-0 looped nylon suture to reduce the risk of hernia formation. The rectus-fascia defect was repaired vertically from top down, as there was more laxity cranially. The deep dermal layer was closed with 2-0 Monocryl^tm suture, and the intradermal layer was closed with a 3-0 Monocryl suture.

In Case 2, a similar surgical technique was performed. However, preoperatively a triangular mini fleur-de-lis marking ⁶ was used as a reference point for excising the vertical laparotomy scar, as well as the underlying endometriotic nodule (Fig. 2). Exploration revealed that the endometriotic nodule extended through the anterior rectus fascia and peritoneum in between the rectus diastasis. The defect in the peritoneum and the anterior rectus fascia was repaired in a continuous fashion with a 1-0 polydioxanone suture. The inset was closed with a 2-0 Monocryl suture (Fig. 3 and Supplementary Video S-1).

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FIG. 2.

Triangular mini fleur-de-lis marking for excision of the vertical laparotomy scar as well as the underlying cesarean-scar endometriosis (Case 2).

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FIG. 3.

Postoperative view after excision (Case 2).

Illustrative Cases

Informed consent was obtained from both patients for the purpose of publishing this article and video.

Discussion

This article and its accompanying Supplementary video present the step-by-step surgical management of 2 cases of CSE.

CSE is considered iatrogenic. Clinicians should maintain high levels of suspicion when managing cases presenting with palpable painful nodules around the cesarean-section incision site.

The recommended surgical technique for CSE involves wide local excision of the lesion with an adequate margin of at least 1 cm to reduce the risk of recurrence.^2,7 However, no studies have addressed if size of the surgical margin has an impact on the rate of recurrence. The rate of recurrence ranges from 4.3% to 29%. ³

In some cases, CSE may involve the rectus abdominis muscle and/or fascia and its resection necessitates en bloc resection of the underlying myofascial elements. It is imperative for surgeons to anticipate the potential risk of hernia formation proactively. Patients must be informed of the potential need for mesh repair or abdominal-wall reconstruction, and possible mesh-related complications such as mesh extrusion and mesh infection should be communicated to patients as well. ⁸ The optimal anatomical placement of the mesh is controversial and there are no comparative studies. If subsequent cesarean sections are anticipated, mesh placement should be avoided. A multidisciplinary approach and the involvement of a plastic surgeon in a joint surgical procedure may be necessary to achieve optimal results, as demonstrated in the accompanying cases video. Advanced plastic surgery techniques, such as abdominal-wall component separation, locoregional flaps, or free flaps may be required for more-extensive lesions. ⁹

A history of dysmenorrhea, dyspareunia, and chronic pelvic pain suggests the presence of pelvic endometriosis; the overall risk of coexistence of pelvic endometriosis with CSE is estimated to be 13%. ³ Patients should be informed and counseled about the option of undergoing laparoscopy for diagnosis and treatment. Preoperative assessment with MRI provides additional information on the depth of the lesion and potential fascial involvement. ¹⁰

The pathophysiology of CSE is likely to involve complex mechanisms; however, the most widely accepted theory is direct implantation. During cesarean section, endometrial cells are believed to implant on the abdominal scar. ³ The surgical procedure itself, along with the associated stress response, can induce immune suppression, while the surgical wound provides a microenvironment that is rich in growth factors and inflammatory mediators, creating a conducive milieu for the survival and proliferation of these endometrial cells, ¹¹ ultimately leading to the development of CSE. Cases of CSE-associated clear-cell carcinoma have been reported; this is a clinically aggressive disease with a high mortality rate. However, the precise incidence remains uncertain. ¹²

Various strategies have been proposed for preventing CSE, including avoiding swabbing the endometrial cavity, using separate needles for uterine and abdominal closure, and closing the peritoneum.^3,5 However, robust evidence supporting the effectiveness of these strategies is lacking. Moreover, the underlying reasons remain unclear why certain women are at higher risk of developing CSE while most women having cesarean sections do not encounter this complication. The current body of evidence on scar endometriosis is primarily derived from case reports, limiting understanding of the condition. Larger prospective studies are needed to provide more-comprehensive insights into the pathophysiology, optimal management strategies, and long-term outcomes—including reproductive outcomes—of CSE.

Conclusions

CSE is a challenging condition that requires a high index of suspicion and comprehensive evaluation. This phenomenon is likely to become more prevalent in view of the rising cesarean-section rate worldwide. Surgical excision with an appropriate margin remains the most-effective treatment for CSE. This article with its accompanying video illustrates the surgical technique for excising a CSE mass that involves the underlying myofascial layer. A joint procedure with a plastic surgeon or a general surgeon and mesh placement may be necessary for complex cases.