Transanal endoscopic microsurgery for the treatment of uncommon rectal lesions

Surgical treatment of retrorectal tumors: a plea for a laparoscopic approach

INTRODUCTION

Retrorectal tumors (RRTs) are rare and often surgically excised due to the risk of malignant degeneration and compressive or obstructive symptoms. The approach for excision has traditionally been based on tumor location and performed using either a transabdominal or perineal approach depending on the position of the tumor. The advent of minimally invasive surgery, however, has challenged this paradigm. Here, we determined the applicability and potential advantages of a laparoscopic transabdominal approach in a series of 23 patients with RRTs.

MATERIAL AND METHODS

We included 23 patients presenting with RRTs treated at the Surgical Gastrointestinal Unit at Hospital de Sant Pau that were registered prospectively since 1998. The preoperative evaluation consisted of colonoscopy, CT scan and/or MRI, mechanical bowel lavage, and antibiotic therapy. Signed consent was obtained from all patients for a laparoscopic transabdominal approach unless the tumor was easily accessible via a perineal approach. In case of recurrence, a transanal endoscopic microsurgery (TEM) approach was considered. Surgical details, immediate morbidity, and short- and long-term outcomes were recorded.

RESULTS

Of the 23 RRT cases evaluated, 16 patients underwent a laparoscopic transabdominal approach and 6 underwent a perineal approach. No patients required conversion to open surgery. In the laparoscopic transabdominal group, the mean operating time was 158 min, the average postoperative hospital stay was 5 days, and postoperative morbidity was 18%. Three patients had recurrent RRTs, two of the three underwent surgical reintervention. The third patient was radiologically stable and close follow-up was decided.

CONCLUSION

Our results show that laparoscopic transabdominal excision of RRT is a safe and effective technique, offering the potential advantages of less invasive access and reduced morbidity. This approach challenges the traditional paradigm of excision of these infrequent tumors based solely on tumor location and offers a viable alternative for the treatment of these infrequent tumors.

Multicenter Analysis of Presacral Neuroendocrine Neoplasms-Clinicopathological Characterization and Treatment Outcomes of a Rare Disease

Background and Aims

Neuroendocrine neoplasms (NENs) of the presacral space are an extremely rare disease entity with largely unknown outcome and no established standard of care treatment. Therefore, we wanted to analyze clinical presentation, histopathological findings, treatment outcomes, and prognosis in a multicentric patient cohort.

Methods

We searched local databases of six German NEN centers for patients with presacral NEN. Retrospective descriptive analyses of age, sex, stage at diagnosis, symptoms, grade, immunohistochemical investigations, biomarkers, treatment, and treatment outcome were performed. Kaplan-Meier analysis was used to determine median overall survival.

Results

We identified 17 patients (11 female, 6 male) with a median age of 50 years (range, 35-66) at diagnosis. Twelve cases presented initially with distant metastases including bone metastases in nine cases. On pathological review the majority of patients had well-differentiated G2 tumors. Immunohistochemical profile resembled rectal NENs. All but one patient had non-functioning tumors. Somatostatin receptor imaging was positive in 14 of 15 investigated cases. Eight patients were treated surgically including palliative resections; 14 patients received somatostatin analogs with limited efficacy. With 14 PRRTs completed, 79% showed clinical benefit, whereas only one patient with neuroendocrine carcinoma (NEC) responded to chemotherapy. Treatment with everolimus in three patients was not successful, whereas cabozantinib resulted in a disease stabilization in a heavily pretreated patient. During a median observation period of 44.5 months, 6 patients died. Median overall survival was not reached.

Conclusion

Presacral NEN are histopathologically similar to rectal NENs. Presacral NEN should be considered as possible primary in NEN of unknown primary. The majority of tumors is non-functioning and somatostatin receptor positive. PRRT demonstrated promising activity; tyrosine kinase inhibitors warrant further investigations. Further molecular characterization and prospective evaluation of this rare tumor entity are needed.