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.

Posterior high sacral segmental disconnection prior to anterior en bloc exenteration for recurrent rectal cancer.

This article describes a novel technique for en bloc resection of locally recurrent rectal cancer that invades the high sacral bone (above S3). The involved segment of the sacrum is mobilised with osteotomes during an initial posterior approach before an anterior abdominal phase where the segment of sacral bone is delivered with the specimen. This allows en bloc resection of the involved sacrum while preserving uninvolved distal and contralateral sacral bone and nerve roots. The goal is to obtain a clear bony margin and offer a chance of cure while improving functional outcomes by maintaining pelvic stability and minimising neurological deficit.

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.

Clinical algorithms for the diagnosis and management of urological leaks following pelvic exenteration.

BACKGROUND: Urine leak following pelvic exenteration for locally advanced pelvic malignancy is a major complication leading to increased mortality, morbidity and length of stay. We reviewed our experience and developed a diagnostic and management algorithm for urine leaks in this patient population. METHODS: Consecutive patients who underwent en bloc cystectomy and conduit formation as part of pelvic exenteration at a single quaternary referral centre from 1995 to 2012 were reviewed. Patients with urine leak were identified. Medical records were reviewed to extract data on diagnosis and management and a suggested clinical algorithm was developed. RESULTS: Of 325 exenterations, there were 102 conduits, of which 15 patients (15%) developed a conduit related urine leak. Most (14/15) patients were symptomatic. Diagnosis was made by drain creatinine studies (12/15) and/or imaging (15/15). Management comprised of conservative management, radiologic urinary diversion, early surgical revision and late surgical revision in 3, 11, 2 and 1 patients respectively. Important lessons from our 17 year experience include a high index of suspicion in a patient who is persistently septic despite appropriate treatment, the importance of regular drain creatinine studies, CT (computer tomography) with delayed images (CT intravenous pyelogram) when performing a CT for investigation of sepsis and early aggressive management with radiologic urinary diversion to facilitate early healing. CONCLUSION: Urine leak after pelvic exenteration is a complex problem. Conservative management usually fails and early diagnosis and intervention is the key. It is hoped that our algorithms will facilitate diagnosis and subsequent management of this group of patients.