EP204 - En bloc sacrectomy in the surgical management of locally advanced rectal cancers – Initial experience at the Philippine General Hospital

Purpose/Background: Locally advanced primary, or recurrent, rectal cancer requires a multimodal approach, with complete pathological clearance as the primary goal of resection. Tumors demonstrating direct involvement of, or an indistinct plane of separation from, the sacrum or presacral fascia on preoperative imaging necessitate an en bloc sacrectomy. This radical and technically-challenging procedure carries significant potential morbidity, which increases with higher levels of sacral transection. Common complications include bleeding, flap failure, wound-related infections, and other infections (e.g., hospital-acquired pneumonia, urinary tract infection). In addition, there are functional consequences related to gait, mobility, and bowel and bladder function that may be expected. This study evaluated the role of an en bloc sacrectomy in achieving an R0 resection, and assessed the intraoperative and postoperative outcomes of patients.

Methods/Interventions: This retrospective study (2020 to 2025) included 5 patients with rectal adenocarcinoma--3 recurrent and 2 locally advanced primary cases. All patients presented with tumors that had an indistinct plane of separation from the presacral fascia and sacrum on pelvic MRI. As the surgical margins appeared threatened, an en bloc sacral resection was decided on. Tumor resectability and absence of distant metastasis were confirmed prior to surgery. All cases were discussed in a multidisciplinary team (MDT) meeting that included: Colorectal Surgery, Orthopedic Surgery, Vascular Surgery, Urology, Plastic and Reconstructive Surgery, Anesthesiology and Pain Medicine, Medical Oncology, Radiation Oncology, and Rehabilitation Medicine. The surgical plan, potential morbidities, and oncologic objectives were thoroughly explained to every patient.

Results/Outcomes: The median patient age was 57 years (range 48-69 years); 4 males and 1 female. Two patients underwent an abdominoperineal resection (APR), while 3 underwent total pelvic exenteration, together with the sacrectomy. The highest level of sacral resection was at S2. A rectus abdominis muscle flap was the method used most often to reconstruct complex pelvic defects to fill dead space, provide coverage, and improve postoperative quality of life.

The median operative time was 17 hours (range, 12-20 hours), median estimated blood loss (EBL) of 3,500ml (range, 800 to 7,000 mL). Four patients required postoperative ICU admission, with a median stay of 2.5 days (range, 1-4 days). The median postoperative length of stay (LOS) was 9 days (range, 7-16 days). The most frequent postoperative complaint of patients was urinary retention. One patient required reoperation for an anastomotic leak, and subsequently died from septic shock.

On histopathologic examination, all specimens were noted to have negative margins. Three patients remain to be negative of disease as of their last follow-up visit. However, 2 of them continue to experience urinary retention. All are independently ambulating. One patient developed an unresectable local recurrence a year after surgery, and has since been lost to follow-up.

Conclusion/Discussion: An en bloc sacrectomy remains a definitive surgical option for rectal cancer with sacral involvement when there is curative intent. Adequate preoperative planning, sound patient selection, and a coordinated multidisciplinary approach are essential. Standardization of surgical technique and refinement of perioperative management are keys to further improving outcomes.

Table 1. Summary of characteristics and outcomes of patients with rectal cancer undergoing an en bloc sacrectomy for primary or recurrent rectal cancer. PGH, 2020-2025
1The patient underwent long-course chemoradiotherapy (LCCRT) prior to the first surgery, and subsequently received adjuvant chemotherapy (FOLFOX).

2The patient underwent RAPIDO prior to the first surgery.

3The patient underwent LCCRT prior to the first surgery, and subsequently received adjuvant chemotherapy (FOLFOX), then Second-line chemotherapy