Postoperative complications, bowel function, and prognosis in restorative proctocolectomy for ulcerative colitis-a single-center observational study of 320 patients

PURPOSE

To determine the selection criteria, postoperative complications, bowel function, and prognosis of stapled ileal pouch-anal anastomosis (IPAA) and hand-sewn IPAA for ulcerative colitis (UC).

METHODS

We defined our surgical indications and strategy, and compared the postoperative complications, bowel function, and prognoses between patients who underwent stapled and hand-sewn IPAA for UC at the Yokohama City University Medical Center between 2004 and 2017.

RESULTS

Among 320 patients enrolled, 298 patients underwent stapled IPAA while 22 underwent hand-sewn IPAA. There was no significant difference in the postoperative complications between the two groups. Regarding postoperative bowel function, stapled IPAA caused significantly less soiling (stapled vs hand-sewn: 9.1% vs 41.0%, odds ratio (OR) = 0.14, p < 0.0002), spotting (stapled vs hand-sewn: 23.2% vs 63.6%, OR = 0.17, p < 0.0001), and difficulty in distinguishing feces from flatus (stapled vs hand-sewn: 39.9% vs 63.6%, OR = 0.36, p < 0.026). No postoperative neoplasia was observed at the final follow-up in all patients.

CONCLUSION

In this study, there was no clear difference in the postoperative complications between stapled and hand-sewn IPAA, but stapled IPAA resulted in better postoperative bowel function. Postoperative oncogenesis from the residual mucosa is rare. However, future cancer risk remains; thus, careful follow-up is required.

Epithelial and ganglionic distribution at the distal rectal end in anorectal malformations: could it play a role in anastomotic adaptation?

PURPOSE

In anorectal malformations (ARMs), the epithelium of the distal rectal end is not well described. We histomorphologically evaluated epithelial and ganglionic distribution in the distal rectal end of ARMs resected during anorectoplasty to assess similarities and differences with normal anal canal structure.

METHODS

In this single-center retrospective study, specimens from 60 ARM patients (27 males, 33 females) treated between 2008 and 2019 were evaluated.

RESULTS

Epithelium type and alignment sequence as well as ganglionic distribution were similar in the distal rectal end and in a normal anal canal. Stratified columnar epithelium (anal transitional zone, ATZ) was seen in 49/60 (81.7%) cases and in all ARM types, including the no-fistula type. Anal crypts were identified in the stratified columnar epithelium (ATZ) of 46/49 (93.9%) patients. Regarding distal rectal end-resecting anorectoplasty, in 90% of patients, resection was performed distal to the Herrmann line. Ganglion cell distribution was exclusively proximal to the Herrmann line.

CONCLUSION

Epithelial and ganglionic distribution was similar in the distal rectal end of ARMs and in a normal anal canal. The ATZ is the epithelial boundary between the rectum and skin in a normal anal canal. ATZ preservation could reproduce anal canal structure in ARM reconstruction.

Sensory innervation of the anal canal and anorectal line in Hirschsprung's disease: histological evidence from mouse models

AIM

We used non-Hirschsprung's disease (HD) Sox10-Venus Transgenic mice (non-HDSV-mice), an endothelin receptor-B knockout mouse model of HD (HD-mice), and C57B6C3 wild controls (C-mice) to identify the correlation between the anorectal line (ARL) and successful transanal pull-through (TAPT).

METHODS

In non-HDSV-mice, intestinal neural crest-derived cells can be visualized with Venus,-a green fluorescent protein-without histochemical staining. We exposed the anal canal in each non-HDSV-mouse and marked the ARL directly with red ink. Specimens of anus and rectum from HD- and C-mice were immunostained with sensory nerve markers substance P and calcitonin gene related peptide (CGRP) and Hematoxylin and Eosin.

RESULTS

Stereoscopic microscopy confirmed a squamous-columnar epithelial junction corresponding to the red ink in non-HDSV-mice. Fluorescence microscopy showed intense Venus expression proximal to the ARL and little enteric nerve expression distally. Substance P and CGRP expression were strong in the basal layer of the anal transitional zone (ATZ) in both HD- and C-mice; i.e., distal sensory innervation was normal in HD-mice.

CONCLUSIONS

The ARL delineated a distinct demarcation in sensory innervation that is normal even in HD-mice. Thus, the initial incision during TAPT should be based on the ARL because it is readily identifiable and intimately involved with bowel function.

Fetal growth of the anal sinus and sphincters, especially in relation to anal anomalies

PURPOSE AND METHODS

The anal sinuses, small furrows above the pectinate line, sometimes form perianal abscesses in adults. We examined the pattern of fetal growth of the anal sinus and sphincters using 22 mid-term (8-18 weeks) and 6 late-stage (30-38 weeks) fetuses.

RESULTS

In mid-term fetuses, the external and internal sphincters gradually increased in thickness, depending on specimen size (from 0.2 to 1.5 mm), whereas the anteroposterior diameter of the anal canal at the epithelial junction was relatively stable (0.5-1.0 mm) irrespective of specimen size. Anal canal diameter increased less than twofold between mid-term and late-stage fetuses, from 0.5-1.0 to almost 2 mm, whereas sphincter thickness increased over tenfold, from 0.2-1.5 to almost 3.5 mm. The anal sinus often showed balloon-like enlargement when the sphincter muscle bundles were tightly packed in mid-term, but not in late-stage fetuses.

CONCLUSIONS

Large concentric mechanical stress from the sphincters in late-stage fetuses apparently prevented the anal sinus from expanding in a balloon-like manner. Conversely, to avoid anal stenosis, the growing sinuses maintained a luminal space of the anal canal in response to stress from rapidly growing sphincters. The inferiorly extending sinus usually provided temporal double canals separated by a thick column. In the presence of double lumens, anal canal duplication is likely to develop without any abnormalities of the anal epithelium and sphincters.