Feasibility of the Reconstruction with Fascia Lata Patch on the Abdominal Wall Defect After Resection of the Abdominal Desmoid Tumor

Introduction

Desmoid tumor is a benign tumor that arises from the myofascial and musculosaurus tissues. This tumor is rare, with an estimated incidence rate of “2.4”–“4.3” per 1 million population.¹ They do not exhibit distant metastasis; however, the tumor tends to strongly infiltrate neighboring tissues, resulting in local recurrence.² The rate of local recurrence is 25%–50%.^3,4 The primary treatment method is complete removal of the tumor to control local recurrence, although surgeons face problems in the reconstruction of the abdominal wall defect after resection.

Case Presentation

A 63-year-old man attended our hospital with heavy abdominal pain in January 2016. The CT revealed a mass with elevation of tissue fascia and free air near the cecum (Figure 1A). Accordingly, the patient was diagnosed with perforation of the cecal diverticulum, and open drainage and construction of ileostomy was performed. After 3 months, the patient received right hemicolectomy and closure of the ileostomy. We did not detect the mass from the resected specimen (Figure 1B), and pathological examination revealed no malignancy.

Figure 1 There was a mass near the cecum. The elevation of tissue fascia and free air were detected (A). There were several small polyps at ileocecal section (B).

The patient experienced a palpable mass in the left abdomen from May 2017 and attended our department in December 2017. The enhanced CT revealed a 38-mm mass, resembling a dyeing ring in the left rectus abdominis muscle. The mass was located near the scar of ileostomy closure (Figure 2). The size of hernia orifice from the epigastrium to the pubic bones was approximately 20 cm.

Figure 2 The enhanced CT in December 2017 showed the mass of 38mm with dyeing ring form in the left rectus abdominis muscle. The mass was located near the ileostomy closure scar. The triangle points to the tumor.

After 4 months, the MRI revealed a 40-mm mass in the left rectus abdominis muscle. T2 weighted image showed a low intensity area similar to muscle (Figure 3A), and the tumor was uniformly enhanced (Figure 3B).

Figure 3 The MRI in April 2018 showed the mass of 40mm in the left rectus abdominis muscle. The mass showed low intensity area like muscle in T2 weighted images (A). It was uniformly enhanced (B). The triangle points to the tumor.

We performed endoscopic ultrasound (EUS) and fine needle aspiration of the mass and reached the pathological diagnosis of desmoid tumor. Because the patient had pain at the mass and at the point of abdominal incisional hernia, we planned resection of the abdominal desmoid tumor and repair of incisional hernia.

We performed a midline incision similar to the previous scar and cut a spindle shape around the mass at 2-cm margin from the mass (Figure 4A). There was no exposure of the tumor at the abdominal side. We used the Harmonic Scalpel^TM (Ethicon Endo-Surgery, Cincinnati) to cut the muscle to prevent bleeding (Figure 4B). Next, we removed the rectus abdominis muscle from the left lateral end. The abdominal wall defect measured 10 cm × 10 cm (Figure 4C). The hernia was repaired with a simple closure using anterior layer of rectus sheath and the defect was closed by suturing the right anterior layer of rectus sheath to the left aponeurosis of external oblique muscle (Figure 4D). Considering the risk of recurrence of abdominal wall hernia at the defect site, we decided to repair the defect with autologous fascia. We used a fascia lata patch measuring 15 cm × 5 cm (Figure 4E) to repair the defect in the left abdomen (Figures 4F and 5A–C).

Figure 4 We performed a midline incision similar to the previous scar and we cut a spindle shape around the mass at 2cm margin from the mass (A). There was no exposure of the tumor to abdominal side. We used ultrasonically activated scalpel when we cut the muscle (B). Next, we removed the rectus abdominis muscle from the left lateral end. The abdominal wall defect was 10cm×10cm (C). The hernia was repaired with a simple closure using anterior layer of rectus sheath and the defect was closed by suturing the right anterior layer of rectus sheath to the left aponeurosis of external oblique muscle (D). We used a fascia lata patch measuring 15 cm × 5 cm (E) to repair the defect in the left abdomen (F).

Figure 5 The final form after resection of tumor (A). The gray zone is the part that was removed. The defect was repaired with a simple closure and the defect was closed by suturing the right anterior layer of rectus sheath to the left aponeurosis of external oblique muscle (B). We used fascia lata patch as on lay mesh on defect (C).

The size of the mass was 45 mm × 45 mm, and it was a solid tumor. The macroscopic view of the resected tumor revealed its whitish color (Figure 6A). Pathological analysis revealed the growth of fibroblasts, defect of the nuclear heteromorphism, and presence of abundant collagen fibers between fibroblasts (Figure 6B). Additionally, a nuclear-positive image of β-catenin was observed on immunostaining (Figure 6C). The pathological diagnosis was desmoid-type fibromatosis. No recurrence of incisional hernia and desmoid tumor was detected 22 months after surgery.

Figure 6 The tissue image is a magnified view of the red square part in the lower right image. The black line at the bottom left shows 50µm. The size of the mass was 45mm×45mm, the cut surface was white (A). The growth of fibroblasts was seen, the nuclear heteromorphic was poor. There was abundant collagen fibers between fibroblasts (B). A nuclear positive image of β-Catenin was observed by immunostaining (C).

Discussion

Desmoid tumor is a benign tumor that arises from the myofascial and musculosaurus tissues, with an estimated incidence of 2.4–4.3 per 1 million population.¹ It has the following clinicopathological features: i) it is rich in differentiated fibroblasts, ii) it has plenty of collagen fibers between fibroblasts, iii) it is not malignant, iv) it tends to strongly infiltrate, and v) it does not show distant metastasis, although local recurrence can occur.² The rate of local recurrence has been reported to be 25–50%.^3,4 The association with FAP, pregnancy, parturition, trauma, and surgical history are considered as risk factors. It is diagnosed by using imaging technologies such as ultrasonography, CT, or MRI. The definitive diagnosis is based on pathological findings such as growth of fibroblasts with collagen fibers between cells.

The primary treatment method is complete removal to prevent local recurrence. Regarding the setting of the resection line, no specific consensus has yet been shown. Rock et al reported the recurrence rate of 68% in overall resected cases, 48% in extensive resection cases, and 90% in marginal resection cases.5 Gronchi et al reported that the recurrence rate is unaffected by whether the margin is positive or negative.⁶ Other studies⁷ have reported that tumor size, age, and occurrence location are predictors.

The methods employed for the treatment of desmoid tumor have changed in the past 5–10 years because surgery itself can be a risk of recurrence and cause complications. Recently, conservative approaches such as pharmacological or simple observation have been selected as treatment.⁷

After the resection of abdominal desmoid tumor, the problem is reconstruction of the abdominal wall defect. Regarding the method of reconstruction of the abdominal wall, besides performing primary closure or using artificial materials such as mesh, reconstruction via transplantation of flap or autologous fascia is selected. The materials used for fascia include anterior layer of rectus sheath, aponeurosis of external oblique muscle, and fascia lata patch. The fascia lata patch is generally preferred because we can easily get resilient and large fascia.⁸ Yamamoto studied cases using fascia lata patch as an onlay mesh to reinforce fascial closure when they overlapped with the defect in the anterior rectus fascia. They found no evidence of recurrence in the median follow-up time of 16.1 months.⁹ Stecco et al described that the fascia lata could be used alone as a mesh and that it is more easily integrated into the new site than an artificial mesh.¹⁰ Hamilton microscopically observed a piece of a patient’s fascia lata patch that was removed 2 years after insertion. They confirmed the presence of dense wavy layers of collagen and numerous small nutrient vessels.¹¹ Thus, the fascia lata patch can repair the defect if the reconstruction is only supportive tissue. It was considered to be useful as a mesh when using autologous tissues, particularly when the use of artifacts was not desired. In addition, fascia lata patch technique is easily performed and comfortable for gastrointestinal surgeons.

In this case, we wanted to achieve complete resection, repair of the large incisional hernia, and reconstruction of the abdominal defect after resection of desmoid tumor. Therefore, we selected a margin of 2 cm and decided to use the fascia lata patch based on the risk of future recurrence. Although the follow-up period is short, we did not experience recurrence of incisional hernia.

Conclusion

We have reported a case of abdominal wall desmoid tumor occurring in combination with a large abdominal incisional hernia. In this case, the tumor could have been caused owing to the history of abdominal surgery. Therefore, considering the risk of recurrence in the future, we used fascia lata patch for reconstruction of the abdominal defect. Although we considered the use of a fascia lata patch to be a useful technique for patients with large incisional hernia, a multicenter trial is deemed necessary to evaluate the risks and benefits of using fascia lata patch.