Surgical treatment of familial adenomatous polyposis: Dilemmas and current recommendations

Abstract

Familial adenomatous polyposis (FAP) is an autosomal dominant inherited syndrome characterized by multiple adenomatous polyps (predisposing to colorectal cancer development) and numerous extracolonic manifestations. The underlying genetic burden generates variable clinical features that may influence operative management. As a precancerous hereditary condition, the rationale of performing a prophylactic surgery is a mainstay of FAP management. The purpose of the present paper is to bring up many controversial aspects regarding surgical treatment for FAP, and to discuss the results and perspectives of the operative choices and approaches. Preferably, the decision-making process should not be limited to the conventional confrontation of pros and cons of ileorectal anastomosis or restorative proctocolectomy. A wide discussion with the patient may evaluate issues such as age, genotype, family history, sphincter function, the presence or risk of desmoid disease, potential complications of each procedure and chances of postoperative surveillance. Therefore, the definition of the best moment and the choice of appropriate procedure constitute an individual decision that must take into consideration patient's preferences and full information about the complex nature of the disease. All these facts reinforce the idea that FAP patients should be managed by experienced surgeons working in specialized centers to achieve the best immediate and long-term results.

Integrating surgery and genetic testing for the modern surgeon

“…In patients with a diseased rectum, rectal preservation is avoided. However, in patients with limited rectal involvement who are willing to undergo lifelong screening every 6 months, total colectomy and ileorectal anastomosis is an option (14).…”

“…About 80-90% of patients with a clinical diagnosis of FAP will be found to have an identifiable mutation in the APC gene (14,15). The APC gene is a tumor-suppressor gene that encodes a large protein of 2,843 amino acids, and a germline mutation in the APC gene, as determined through genetic testing, is required for a definitive diagnosis of FAP (11,12,16).…”

“…When the specific mutation is unknown a two tier approach is performed, where first an attempted detection of a known mutation in exons 10,11,8,13,14,15, and 16 is carried out and if a positive result is not obtained reflex sequencing of the entire RET gene is performed (51). Whole gene sequencing is currently the most expensive testing method.…”

“…Large deletions and rearrangements can be identified using southern blot and karyotype analysis through primer annealing to specific genetic fragments. Karyotype analysis or fluorescent in situ hybridization can only be used for the largest gene deletions (14).…”

Segmental resection with primary anastomosis is not always safe in splenic flexure perforation

“…This may also hold for sepsis complicating an iatrogenic colonic perforation in FAP. However, light clothing, hot climate, high residue diet (vegetables), poor availability of appliances, sepsis-induced high ileostomy output and cultural taboos make the management of an ileostomy more difficult in the tropics, and so ileorectal anastomosis with endoscopic surveillance is preferred unless the rectum is extensively diseased [ 18 , 19 ]. Another option would have been to exteriorize the perforation as a double-barrelled stoma (Paul Mikulicz procedure) [ 14 , 20 ].…”