Postoperative complications after stapled and hand‐sewn ileal pouch‐anal anastomosis for familial adenomatous polyposis: A multicenter study

Abstract Ileal pouch‐anal anastomosis (IPAA) after total proctocolectomy (TPC) can be conducted with either hand‐sewn or stapled anastomosis for patients with familial adenomatous polyposis (FAP). Although stapled IPAA without mucosectomy has a higher risk for developing adenomas in the remnant mucosa, it is the simpler procedure with potential benefit in short‐term outcomes. However, it remains controversial as to whether stapled IPAA has any advantages in reducing postoperative complications. The aim of the present study was to compare the postoperative complications and short‐term outcomes of stapled and hand‐sewn IPAA for patients with FAP, using a multicenter cohort sample in Japan. Data of 143 patients with FAP who underwent TPC with stapled IPAA (n=37) and hand‐sewn IPAA (n=106) at 23 institutions between 2000 and 2012 were collected. Postoperative complications, proportion of ostomy, fecal continence and overall survival were compared. Overall rates of the Clavien‐Dindo grade II‐IV complications were not different between the two groups (19% in stapled vs 25% in hand‐sewn, P=.42), with significantly fewer pouch‐related complications including leakage, pelvic abscess, vaginal fistula and anastomotic stricture in stapled IPAA (none in stapled vs 11% in hand‐sewn, P=.036). There was no mortality. Proportion of ostomy at 12 months was similar (2.7% in stapled vs 4.3% in hand‐sewn, P=.26). Mean Wexner score was similar. (0.47 in stapled vs 2.0 in hand‐sewn, P=.12). Five‐year overall survival excluding Stage IV patients was 96% in both groups. Stapled IPAA is a safe option in patients with FAP with a potential benefit in reducing pouch‐related complications.

Overall rates of the Clavien-Dindo grade II-IV complications were not different between the two groups (19% in stapled vs 25% in hand-sewn, P=.42), with significantly fewer pouch-related complications including leakage, pelvic abscess, vaginal fistula and anastomotic stricture in stapled IPAA (none in stapled vs 11% in handsewn, P=.036). There was no mortality. Proportion of ostomy at 12 months was similar (2.7% in stapled vs 4.3% in hand-sewn, P=.26). Mean Wexner score was similar. (0.47 in stapled vs 2.0 in hand-sewn, P=.12). Five-year overall survival excluding Stage IV patients was 96% in both groups. Stapled IPAA is a safe option in patients with FAP with a potential benefit in reducing pouch-related complications.  1 Total proctocolectomy (TPC) with ileal pouch-anal anastomosis (IPAA) has been established as a standard procedure for minimizing the risk of cancer death. Since the first report by Parks and Nicholls in 1978, 2 IPAA was originally conducted by handsewn technique with mucosectomy down to the dentate line to eliminate all mucosa at risk. With the development of staple devices in the 1980s, stapled IPAA without mucosectomy has been increasingly conducted. [3][4][5][6] Previous studies have reported several pros and cons on these two anastomotic techniques. Stapled IPAA is the simpler type of anastomosis with shorter length of operation and better fecal continence possibly as a result of omission of mucosectomy and preservation of the anal transitional zone (ATZ). 5,[7][8][9][10] In contrast, hand-sewn IPAA with mucosectomy can reduce a substantial risk for developing adenomas at the anastomotic site. 11 Previous studies have shown inconsistent results on postoperative complications after these two procedures. Some studies found higher incidence of septic complications, fistula and anastomotic stricture after hand-sewn IPAA, 5,9,12 whereas other studies showed a trend toward higher incidence of overall complications and stricture after stapled IPAA. 13,14 Importantly, most of the previous studies included patients with ulcerative colitis (UC) rather than patients with FAP 5,8,14,15 although the complication rates were different between such patients. 5,8,14,15 Furthermore, none of the studies used objective criteria such as the Clavien-Dindo classification for stratifying the complications. 5,8,9,[12][13][14][15] These limitations could explain inconsistent results in the previous studies, and we need evidence that focuses on patients with FAP with the use of objective criteria for assessing complications. The aim of the present study was to compare postoperative complications and short-term outcomes after stapled and hand-sewn IPAA for patients with FAP using multicenter data in Japan. [16][17][18] 2 | MATERIALS AND METHODS

| Original data sources for this study
Original data for this study were compiled from 23 institutions that are members of the Japanese Society for Cancer of the Colon and Rectum (JSCCR), which includes the departments of surgery, internal medicine, pathology, and radiology at hospitals throughout Japan. 19,20 All patients diagnosed as having FAP and undergoing colorectal resection in each institution between the years 2000 and 2012 were retrospectively collected and registered for the database as described previously. [16][17][18] Patients having a previous history of colorectal resections were excluded from the database to avoid dou-

| Patient selection and data extraction
Data of all patients undergoing TPC with IPAA were extracted from the database. Clinical variables, postoperative complications and overall survival were compared between patients undergoing stapled IPAA and hand-sewn IPAA.

| Primary and secondary endpoints
Primary endpoint of the present study was the rate of postoperative complications which were stratified according to the Clavien-Dindo classification. 23 Evaluated complications included anastomotic leakage, pelvic abscess, vaginal fistula, anastomotic stricture, ileus/bowel obstruction, wound infection, cardiovascular event and others.
Pouch-related complications were defined as described previously by Ganschow et al., 13 including anastomotic leakage, pelvic abscess, vaginal fistula and anastomotic stricture. Extra-pelvic complications were defined as those other than pouch-related complications. Secondary endpoints included proportion of ostomy after surgery, anal function evaluated by the Wexner fecal incontinence score, overall survival after surgery and incidence of desmoid tumors. The Wexner fecal incontinence score consisted of the score sum of five parameters (frequency of gas, liquid or solid incontinence, need to wear a pad and lifestyle alterations) scored on a scale of 0 (absent) to 4 (daily). 24 A total score of 0 suggested full continence and a score of 20 complete fecal incontinence. Data on the Wexner fecal incontinence score were collected retrospectively from medical charts at the time of registration to the study.

| Statistical analysis
Statistical analysis was carried out using JMP software V 9.0.0 (SAS Institute, Cary, NC, USA). To compare stapled and hand-sewn IPAA, univariate analysis was done using Pearson's v 2 -test or Fisher's exact probability test for categorical variables and Wilcoxon/Kruskal-Wallis rank-sum test for continuous variables. Survival, incidence of desmoid tumors and proportion of ostomy after surgery were analyzed using the Kaplan-Meier method and log-rank test. Patients who were alive and with ostomy at the last follow up were treated as censored, respectively. P values <.05 were considered to be significant.  Table 1.

| RESULTS
There were no differences regarding patient characteristics or  Overall rates of grade III-IV severe pouch-related complications were also marginally fewer in stapled IPAA (none vs 9.4%, P=.064). Anastomotic stricture was the most frequent pouch-related complication followed by pelvic abscess after hand-sewn IPAA. In contrast, overall rates of extra-pelvic complications were not different between the groups. Ileus/bowel obstruction was the most frequent complication in both groups. Figure 1 shows the proportion of ostomy after surgery. The proportion of ostomy was similarly decreased in the two groups (11% and 13% at 6 months, 2.7% and 4.3% at 12 months in stapled and handsewn IPAA, respectively). Median duration from IPAA to ostomy closure was 108 days after stapled IPAA and 120 days after hand-sewn IPAA (

| DISCUSSION
The present multicenter retrospective study analyzed short-term outcomes of a total of 143 patients who underwent restorative TPC for FAP in Japan, including 37 stapled IPAA and 106 hand-sewn IPAA. Hand-sewn IPAA with mucosectomy is generally accepted as a time-consuming and complicated procedure. 25 13,26,27 This could be partially explained by the newer study period of the present series in which surgical devices and techniques were much improved compared with the period before 2000. In addition, a high proportion of covering ileostomy of over 60% could have contributed to reduce anastomotic complications.
There have been conflicting results on the advantages of stapled IPAA in reducing postoperative complications over hand-sewn IPAA.
Although some authors showed favorable results toward stapled IPAA, 5,9,12 others reported no benefit or a trend toward higher complications. 13,14 In the present study, the analysis revealed no signifi- between these two techniques. 9,13 In the present study, ostomy was In conclusion, grade II-IV pouch-related complications were fewer in stapled IPAA compared to hand-sewn IPAA in patients with FAP, whereas there were no differences in incidence of overall complications, fecal incontinence score, proportion of ostomy and overall survival between the two procedures. Stapled IPAA is a safe option in patients with FAP with a potential benefit in reducing pouchrelated complications.