Total anorectal reconstruction: a novel technique

Vascularized anal autotransplantation model in rats: preliminary report

Ostomy has served as an effective surgery for various anorectal disfunctions. However, it must also be noted that those patients suffered greatly from stresses caused by their stoma. Many alternative therapies have been developed, but none have solved this critical issue. Meanwhile, due to the improvements in operative methods and immunosuppressive therapy, allotranplantation has gained great popularity in recent years. Therefore, we began development of an anal transplantation model. The operation was performed in six adult Wistar rats that were divided into two groups. Group 1 underwent vascular anastomoses, while group 2 did not Group 1 grafts survived, fully recovering anal function. However, many of the group 2 grafts did not survive; those that did survive showed major defects in their anus, never recovering anal function. We succeeded in establishing the rat anal transplantation model utilizing super-microsurgery. While research in anal transplantation was behind compared to that in other fields, we hope that this model will bring significant possibilities for the future.

Anorectal autotransplantation in a canine model: the first successful report in the short term with the non-laparotomy approach

Colostomy is conventional treatment for anal dysfunction. Recently, a few trials of anorectal transplantation in animals have been published as a potential alternative to colostomies; however, further development of this technique is required. In this study, we utilized a canine model of anorectal transplantation, evaluated the patency of our microsurgical anastomoses, and assessed the perfusion of the transplanted anus. We designed a canine anorectal transplantation model, wherein anorectal autotransplantation was performed in four healthy beagle dogs by anastomoses of the lower rectum, the bilateral pudendal arteries (PAs) and veins (PVs), and pudendal nerves (PNs). Postoperative graft perfusion was measured by indocyanine green (ICG) angiography and histological examination. The length of the anorectal graft including perianal skin, anal sphincter muscle, bilateral PAs, PVs, and PNs was 4.9 ± 0.3 cm. All diameters of the PAs, PVs, and PNs were large enough to be microscopically anastomosed. Both ICG angiography and histological examination demonstrated good graft perfusion, except for one case that lead to venous congestion. These results show that anastomosis of the bilateral PAs, PVs, and PNs is required for anorectal transplantation. This is the first successful report of canine anorectal autotransplantation.

The antegrade continence enema procedure and total anorectal reconstruction

Patients may present with anal incontinence (AI) following repair of a congenital anorectal anomaly years previously, or require total anorectal reconstruction (TAR) following radical rectal extirpation, most commonly for rectal cancer. Others may require removal of their colostomy following sphincter excision for Fournier's gangrene, or in cases of severe perineal trauma. Most of the data pertaining to antegrade continence enema (the ACE or Malone procedure) comes from the pediatric literature in the management of children with AI, but also with supervening chronic constipation, where the quality of life and compliance with this technique appears superior to retrograde colonic washouts. Total anorectal reconstruction requires an anatomical or physical supplement to the performance of a perineal colostomy, which may include an extrinsic muscle interposition (which may or may not be 'dynamized'), construction of a neorectal reservoir, implantation of an incremental artificial bowel sphincter or creation of a terminal, smooth-muscle neosphincter. The advantages and disadvantages of these techniques and their outcome are presented here.

Use of the gluteus maximus muscle as the neosphincter for restoration of anal function after abdominoperineal resection

BACKGROUND

Our aim was to evaluate complications and long-term functional outcome in patients who had sphincter reconstruction using the gluteus maximus muscle as the neosphincter after abdominoperineal resection for rectal cancer treatment.

METHODS

Seven patients underwent reconstruction from 2000 to 2010. First, the sigmoid colon was brought down to the perineum as a perineal colostomy, with the procedure protected by a loop ileostomy. Reconstruction of the sphincter mechanism using the gluteus maximus took place 3 months later, and after another 8-12 weeks, the loop ileostomy was closed. We studied the functional outcome of these interventions with follow-up interviews of patients and objectively assessed anorectal function using manometry and the Cleveland Clinic Florida (Jorge-Wexner) fecal incontinence score.

RESULTS

The mean follow-up was 56 months (median 47; range 10-123 months). One patient had a perianal wound infection and another had fibrotic stricture in the colocutaneous anastomosis that required several digital dilatations. Anorectal manometry at 3-month follow-up showed resting pressures from 10 to 18 mm Hg and voluntary contraction pressures from 68 to 187 mm Hg. Four patients had excellent sphincter function (Jorge-Wexner scores ≤5).

CONCLUSIONS

Our preliminary results show that sphincter reconstruction by means of gluteus maximus transposition can be effective in restoring gastrointestinal continuity and recovering fecal continence in patients who have undergone APR with permanent colostomy for rectal cancer. Furthermore, the reconstruction procedure can be performed 2-4 years after the APR.

Low anterior resection syndrome (LARS): cause and effect and reconstructive considerations

Between 25 and 80% of patients undergoing a low or very low anterior resection will suffer postoperatively, from a constellation of symptoms including fecal urgency, frequent bowel movements, bowel fragmentation and incontinence, collectively referred to as the low anterior resection syndrome (LARS). The etiology of LARS is multifactorial with the potential of sphincter injury during anastomosis construction, alterations in anorectal physiology, the development of a pudendal neuropathy, and a lumbar plexopathy with exacerbation of symptoms if there is associated anastomotic sepsis or the use of adjuvant and neoadjuavnt therapies. The symptoms of LARS may be obviated in part by the construction of a neorectal reservoir which may take the form of a colonic J-pouch, a transverse coloplasty, or a side-to-end anastomosis. This review outlines the factors contributing to LARS symptomatology along with the short- and medium-term functional results of comparative trials with the different types of neorectal reconstructions.

The development of a canine anorectal autotransplantation model based on blood supply: a preliminary case report

Colostomy is conventionally the only treatment for anal dysfunction. Recently, a few trials of anorectal transplantation in animals have been published; however, further development of this technique is required. Moreover, it is crucial to perform this research in dogs, which resemble humans in anorectal anatomy and biology. We designed a canine anorectal transplantation model, wherein anorectal autotransplantation was performed by anastomoses of the rectum, inferior mesenteric artery (IMA) and vein, and pudendal nerves. Resting pressure in the anal canal and anal canal pressure fluctuation were measured before and after surgery. Graft pathology was examined three days after surgery. The anal blood supply was compared with that in three beagles using indocyanine green (ICG) fluorescence angiography. The anorectal graft had sufficient arterial blood supply from the IMA; however, the graft's distal end was congested and necrotized. Functional examination demonstrated reduced resting pressure and the appearance of an irregular anal canal pressure wave after surgery. ICG angiography showed that the pudendal arteries provided more blood flow than the IMA to the anal segment. This is the first canine model of preliminary anorectal autotransplantation, and it demonstrates the possibility of establishing a transplantation model in dogs using appropriate vascular anastomoses, thus contributing to the progress of anorectal transplantation.

Functional outcome following restorative rectal cancer surgery

The trend towards preoperative adjuvant and neoadjuvant therapies in selected patients with rectal cancer has led to increases in sphincter preservation with a limited understanding of the factors governing unsatisfactory functional outcomes. Data would suggest the need for a more selective use of standard radiotherapeutic fields in low- to intermediate-risk cases where there appears to be limited survival or locoregional recurrence benefit and where there is under-reported toxicity. This article discusses the complex factors which impact on functional outcome following open rectal cancer surgery particularly when it is accompanied by adjuvant therapy.