Reconstruction of the irradiated extended abdominoperineal excision (APE) defect for locally advanced colorectal cancer.

PURPOSE: There is substantial evidence for neoadjuvant chemoradiotherapy and extended abdominoperineal excision (APE) for improving local recurrence rates and overall survival for rectal carcinoma. While oncologic outcomes are improved, the large irradiated defect in the pelvic floor can potentiate poor operative outcomes. We describe a reconstructive option, the inferior gluteal artery myocutaneous (IGAM) transposition flap, which can enable wide tumour resections by providing substantial non-irradiated tissue bulk. METHODS: Ten consecutive patients underwent either standard APE with direct primary closure or extended APE with IGAM transposition flap reconstruction between 2007 and 2009 for mStage I-IIIC disease. Patients underwent staging computed tomography and pelvic magnetic resonance imaging, and neoadjuvant chemoradiotherapy after multi-disciplinary team discussion. Eight patients underwent extended APE and IGAM transposition flap reconstruction due to locally advanced stage of their carcinoma. Oncologic, reconstructive and post-operative outcomes were assessed. RESULTS: All cases demonstrated good closure of the APE defect, with no intra-operative perforations and no immediate operative complications. Histological margins were clear (R0) in all specimens, with mean closest distance to margin 10.8 mm (range 4-20 mm). Mean follow-up was 11.3 months, with no locoregional recurrences. There was no donor site morbidity and no perineal hernia; patients reported high degrees of satisfaction with aesthetic outcome. CONCLUSION: As the extended APE becomes increasingly utilized for rectal carcinoma, a reliable reconstructive option is increasingly important. The IGAM island transposition flap imports well-vascularized, non-irradiated tissue to reconstruct the defect, provides tissue bulk and potentiates good oncologic and reconstructive outcomes.

Risk factors for colonic perforation after screening computed tomographic colonography: a multicentre analysis and review of the literature.

BACKGROUND: Computed tomographic (CT) colonography (or 'virtual' colonoscopy) has become an increasingly popular tool for colorectal cancer screening. Colonic perforation, an uncommon complication, is a risk that has not been widely reported. METHODS: A systematic review of the literature was undertaken to identify all reported risk factors for colonic perforation following CT colonography. In addition, a retrospective multicentre study was undertaken, evaluating all CT colonographies in 10 major metropolitan tertiary referral centres. All colonic perforations were assessed for risk factors. RESULTS: A range of 'patient'-related and 'procedure'-related risk factors were identified in the literature. Among 3458 CT colonographies, there were two cases of colonic perforation contributing to an incidence of perforation of 0.06%. There was no statistical correlation between the incidence of perforation and institutional experience (P = 0.66). Risk factors common to both cases and the literature included age, recent colonoscopy and manual colonic insufflation. Diverticular disease and recent colonic biopsy were also notable factors. CONCLUSION: There is a small but real risk of perforation following CT colonography. Patient selection and preventative procedural measures may reduce this risk. The importance of the consent process is emphasized.

Biallelic PMS2 mutations and a distinctive childhood cancer syndrome.

Biallelic mutations in PMS2, a gene usually associated in heterozygous form with hereditary nonpolyposis colorectal cancer (HNPCC), results in a recently described childhood cancer syndrome. The tumor spectrum encompasses atypical brain cancers, hematologic malignancies, and colonic polyposis and cancer. Cutaneous stigmata resembling café-au-lait macules with more diffuse margins are frequently seen. Onset is as young as 2 years. The risk of second malignancy is high. Evidence exists for surveillance for bowel cancer, but surveillance for the wider tumor spectrum is of uncertain benefit. We report a consanguineous Australian-Lebanese family with multiple affected individuals shown to be homozygous for a PMS2 exon 7 deletion. We also review published cases of biallelic mutations in HNPCC-related genes. Early recognition of this familial cancer syndrome is critical, and should prompt investigation for familial HNPCC mutations.