Complete resection of the iliac vascular system during pelvic exenteration: an evolving surgical approach to lateral compartment excision

Tumour infiltration of the lateral pelvic compartment has previously been associated with the highest rate of involved resection margins and carries significant risk of morbidity. In this study, consecutive patients undergoing pelvic exenteration at a single centre between 1994 and 2019 who required en bloc resection of the common or external iliac artery or vein were included.The results demonstrate that complete resection of the iliac vascular system, including resection and reconstruction of the common and external iliac vessels, can be performed safely during pelvic exenteration with oncological outcomes comparable to more central tumours.

The role of MRI pelvimetry in predicting technical difficulty and outcomes of open and minimally invasive total mesorectal excision: a systematic review

BACKGROUND

The difficulty of performing total mesorectal excision (TME) for rectal cancer partly relies on the surgeon's subjective assessment of the individual patient's pelvic anatomy and tumour characteristics, which generally influences the choice of platform used (open, laparoscopic, robotic or trans-anal surgery). Recent studies have found associations between several anatomical pelvic measurements and surgical difficulty. The aim of this study was to systematically review existing data reporting the use of magnetic resonance imaging (MRI)-based pelvic measurements to predict technical difficulty and outcomes of TME, and determine whether pelvimetry could optimise patient-specific selection of a particular surgical approach.

METHODS

MEDLINE, Embase and Cochrane Library databases were systematically searched for studies reporting MRI-based pelvic measurements in patients undergoing surgery for rectal cancer, and the effect of these measurements on surgical difficulty.

RESULTS

Eleven studies reporting the association between MRI-pelvimetry measurements and rectal cancer surgical outcomes were included. Indicators for surgical difficulty used in the included studies were involved circumferential resection margin, longer operative time, incomplete TME, higher blood loss, anastomotic leak, conversion to open surgery and overall complications. Bony pelvic measurements which were associated with increased surgical difficulty in more than one study were a smaller interspinous distance, a smaller intertubercle distance, a smaller pelvic inlet and larger pubic tubercle height. Two studies identified larger mesorectal fat area as a predictor of surgical difficulty.

CONCLUSIONS

Bony pelvic measurements may predict surgical difficulty during TME, however, use of different indicators of difficulty limit comparison between studies. Early data suggest MRI soft tissue measurements may predict surgical difficulty and warrants further investigation.

Is neoadjuvant chemoradiotherapy sufficient in patients with advanced rectal malignancy and positive extra-mesorectal lateral lymph nodes?

AIM

There is current debate about the optimal management of lateral pelvic lymph nodes (LPLNs) in rectal cancer between Western and Eastern centres. This paper aims to report the rate of histologically proven positive LPLNs in a group of patients undergoing the conventional Western approach to primary and recurrent rectal cancer.

METHOD

A retrospective cohort review of all patients who underwent LPLN dissection at Royal Prince Alfred Hospital in Sydney, Australia. This included patients who underwent pelvic exenteration who had LPLNs excised either en bloc for laterally invasive or recurrent tumours or as part of selective node dissection for suspicious lymph nodes on preoperative imaging. Histopathological results for these patients were compared with node status at preoperative imaging.

RESULTS

Seventy-one patients satisfied the inclusion criteria. Of those patients with positive nodes on histology, 27% (9/33) with radiologically positive LPLNs were treated with preoperative radiotherapy and 75% (9/12) with radiologically positive LPLNs were not treated with preoperative radiotherapy (P = 0.004). None of the 12 patients with radiologically negative nodes treated with radiotherapy had positive nodes; 25% (3/12) of the patients with radiologically negative nodes who were not treated with radiotherapy had positive nodes. Fifty-three per cent of patients developed postoperative complications.

CONCLUSION

Our study suggests that in patients with radiologically positive LPLNs chemoradiotherapy may not be enough to sterilize these extra-mesorectal lymph nodes as a large proportion (27%) will have residual viable adenocarcinoma cells. In patients with radiologically negative LPLNs, however, the addition of chemoradiotherapy may serve to adequately sterilize these lymph nodes without the need for prophylactic LPLN dissection.

Addressing the empty pelvic syndrome following total pelvic exenteration: does mesh reconstruction help?

AIM

Perineal wound complications and pelvic abscesses remain a major source of morbidity after total pelvic exenteration. The void created in the pelvis after these multi-visceral resections leads to fluid accumulation and translocation of bowel within the pelvic cavity, which may increase the risk of pelvic abscess, perineal fluid discharge with perineal wound dehiscence and prolonged ileus. This study describes a novel technique using degradable synthetic mesh with overlying omentum to preclude small bowel and fill the empty space after total pelvic exenteration, and aimed to investigate the rate of pelvic abscess and perineal wound-related complications in this group.

METHOD

Ten patients who underwent total pelvic exenteration followed by implantation of degradable synthetic mesh at a quaternary referral centre were identified and included. The mesh was moulded to the contours of the bony pelvis at the level of the pubic symphysis anteriorly and inferior to the sacral promontory posteriorly. The data on the number of postoperative perineal wound-related complications including pelvic abscesses were collected.

RESULTS

There was no perioperative mortality. Five patients (50%) developed postoperative complications. One patient developed an abscess inferior to the mesh that required surgical drainage and another had a pre-sacral collection that was successfully managed conservatively. Two patients developed intra-abdominal collections requiring percutaneous drainage. Median length of stay was 20 days (range 16-35). No perineal hernia or entero-perineal fistula was detected in any patient either clinically or radiologically at a median follow-up of 7 months.

CONCLUSION

Degradable synthetic mesh reconstruction following exenterative surgery may reduce postoperative complications related to the perineal wound.

Progress and future direction in the management of advanced colorectal cancer

Improving advanced colorectal cancer care

Lateral pelvic compartment excision during pelvic exenteration

BACKGROUND

Involvement of the lateral compartment remains a relative or absolute contraindication to pelvic exenteration in most units. Initial experience with exenteration in the authors' unit produced a 21 per cent clear margin rate (R0), which improved to 53 per cent by adopting a novel technique for en bloc resection of the iliac vessels and other side-wall structures. The objective of this study was to report morbidity and oncological outcomes in consecutive exenterations involving the lateral compartment.

METHODS

Patients undergoing pelvic exenteration between 1994 and 2014 were eligible for review.

RESULTS

Two hundred consecutive patients who had en bloc resection of the lateral compartment were included. R0 resection was achieved in 66·5 per cent of 197 patients undergoing surgery for cancer and 68·9 per cent of planned curative resections. For patients with colorectal cancer, a clear resection margin was associated with a significant overall survival benefit (P = 0·030). Median overall and disease-free survival in this group was 41 and 27 months respectively. Overall 1-, 3- and 5-year survival rates were 86, 46 and 35 per cent respectively. No predictors of survival were identified on univariable analysis other than margin status and operative intent. Excision of the common or external iliac vessels or sciatic nerve did not confer a survival disadvantage.

CONCLUSION

The continuing evolution of radical pelvic exenteration techniques has seen an improvement in R0 margin status from 21 to 66·5 per cent over a 20-year interval by routine adoption of a more lateral anatomical plane. Five-year overall survival rates are comparable with those for more centrally based tumours.