New anti-mesenteric delta-shaped stapled anastomosis: Technical report with short-term postoperative outcomes in patients with Crohn’s disease

BACKGROUND Medical treatment for Crohn’s disease(CD)has continuously improved,which has led to a decrease in surgical recurrence rates.Despite these advancements,25%of patients will undergo repeat intestinal surgery.Recurrence of CD com-monly occurs on the mesentery side of the anastomosis site.AIM To compare the new anti-mesenteric side-to-side delta-shaped stapled anasto-mosis(DSA)with the conventional stapled functional end-to-end anastomosis(CSA).METHODS This retrospective study included CD patients who underwent ileo-ileal or ileo-colic anastomosis between January 2020 and December 2023.The DSA technique employed a stapler to maintain the concept of anti-mesentery side-to-side ana-stomosis by performing a 90°vertical closure of the open window compared with the CSA technique.At the corner where the open window is closed,the DSA avoids forming a pouch and creates an anastomosis resembling a delta shape within the intestinal lumen.We compared demographics,preoperative condition,operative findings,and operative outcomes for the two techniques.RESULTS The study included 175 patients,including 92 in the DSA group and 83 in the CSA group.The two groups were similar in baseline characteristics,preoperative medical treatment,and operative findings except for the Montreal classification location.The 30-days postoperative complication rate was signi-ficantly lower in the DSA group compared with the CSA group(16.3%vs 32.5%,P=0.009).Ileus incidence was significantly lower in the DSA group than in the CSA group(4.3%vs 14.5%,P=0.033),and the hospital stay was shorter in the DSA group than in the CSA group(5.67±1.53 days vs 7.39±3.68 days,P=0.001).CONCLUSION The DSA technique was feasible and showed comparable postoperative outcomes with lower short-term complic-ations compared with the CSA technique.Further studies on CD recurrence and long-term complications are warranted.

Colonic J-pouch anal anastomosis after ultralow anterior resection with upper sphincter excision for low-lying rectal cancer

AIM:There is some evidence of functional superiority of colonic J-pouch over straight coloanal anastomosis (CM) in ultralow anterior resection (ULAR) or intersphincteric resection. On the assumption that colonic J-pouch anal anastomosis is superior to straight CM in ULAR with upper sphincter excision (USE: excision of the upper part of the internal sphincter) for low-lying rectal cancer, we compare functional outcome of colonic J-pouch vsthe straight CM. METHODS: Fifty patients of one hundred and thirty-three rectal cancer patients in whom lower margin of the tumors were located between 3 and 5 cm from the anal verge received ULAR including USE from September 1998 to January 2002. Patients were randomized for reconstruction using either a straight (n = 26) or a colonic J-pouch anastomosis (n = 24) with a temporary diverting-loop ileostomy. All patients were followed-up prospectively by a standardized questionnaire [Fecal Inco-ntinence Severity Index (FISI) scores and Fecal Incontinence Quality of Life (FIQL) scales]. RESULTS: We found that, compared to straight anastomosis patients, the frequency of defecation was significantly lower in J-pouch anastomosis patients for 10 mo after ileostomy takedown. The FISI scores and FIQL scales were significantly better in J-pouch patients than in straight patients at both 3 and 12 mo after ileostomy takedown. Furthermore, we found that FISI scores highly correlated with FIQL scales. CONCLUSION: This study indicates that colonic J-pouch anal anastomosis decreases the severity of fecal incontinence and improves the quality of life for 10 mo after ileostomy takedown in patients undergoing ULAR with USE for low-lying rectal cancer.

Ratio of metastatic lymph nodes is more important for rectal cancer patients treated with preoperative chemoradiotherapy

AIM:To evaluate the predictive value of the lymph node(LN) ratio(LNR,number of metastatic LNs/ examined LNs) for recurrence in patients with rectal cancer and to compare its applicability according to preoperative chemoradiotherapy(PCRT).METHODS:From 2000 to 2009,967 patients with metastatic LNs after curative resection for locally advanced rectal cancer were identified.Patients were categorized according to PCRT(PCRT vs No PCRT).The cut-off LNR was determined based on the p N1 vs p N2 when the recommended number of LNs was harvested.The 5-year recurrence-free survival(RFS) rates using the Kaplan-Meier method were compared according to p/yp N stage and the LNR in each group.RESULTS:Among patients with the same p/yp N stage,the 5-year RFS rate differed according to the LNR.In addition,the 5-year RFS rate was significantly different between p N and LNR groups in patients with No PCRT.In PCRT group,however,only LNR was associated with prognosis.On multivariate analysis,both p N and LNR were significant independent prognostic factors for 5-year RFS in the No PCRT group.In the PCRT group,only LNR category was found to be associated with RFS(HR = 2.36,95%CI:1.31-3.84,and P = 0.001).CONCLUSION:The LNR is an important prognostic predictor of RFS in rectal cancer patients especially treated with PCRT.Current p N categories could not discriminate between prognostic groups of RFS after PCRT.

Intestinal endometriosis:Diagnostic ambiguities and surgical outcomes

BACKGROUND Endometriosis is a common disease for women of reproductive age. However,when it involves intestines, it is difficult to diagnose preoperatively because its symptoms overlap with other diseases and the results of evaluations can be unspecific. Thus it is important to know the clinical characteristics of intestinal endometriosis and how to exactly diagnose.AIM To analyze patients in whom intestinal endometriosis was diagnosed after surgical treatments, and to evaluate the clinical characteristics of preoperatively misdiagnosed cases.METHODS We retrospectively reviewed the pathologic reports of 30 patients diagnosed as having intestinal endometriosis based on surgical specimens between January2000 and December 2017. We reviewed their clinical characteristics and surgical outcomes.RESULTS Twenty-three(76.6%) patients showed symptoms associated with endometriosis,with dysmenorrhea being the most common(n = 9, 30.0%). Thirteen patients(43.3%) had a history of pelvic surgeries. Ten patients(33.3%) had a history of treatment for endometriosis. Only 4 patients(13.3%) had a diagnosis of endometriosis based on endoscopic biopsy findings. According to preoperative evaluations, 13 patients(43.3%) had an initial diagnosis of pelvic endometriosis and 17 patients(56.6%) were misdiagnosed as having other diseases. The most common misdiagnosis was submucosal tumor in the large intestine(n = 8, 26.7%),followed by malignancies of the colon/rectum(n = 3, 10.0%) and ovary(n = 3,10.0%). According to the Clavien-Dindo classification, 5 complications were grade I or II and 2 complications were grade IIIa. The median follow-up period was 26.9(0.6-132.1) mo, and only 1 patient had a recurrence of endometriosis.CONCLUSION Intestinal endometriosis is difficult to diagnose preoperatively because it mimics various intestinal diseases. Thus, if women of reproductive age have ambiguous symptoms and signs with nonspecific radiologic and/or endoscopic findings,intestinal endometriosis should be included in the differential diagnosis.

Impression of prognosis regarding pathologic stage after preoperative chemoradiotherapy in rectal cancer

AIM: To ascertain pathologic stage as a prognostic indicator for rectal cancer patients receiving preoperative chemoradiotherapy(PCRT).METHODS: Patients with mid- and low rectal carcinoma(magnetic resonance imaging- based clinical stage Ⅱ or Ⅲ) between 2000 and 2009 and treated with curative radical resection were identified. Patients were divided into two groups: PCRT and No-PCRT. Recurrence-free survival(RFS) was examined according to pathologic stage and addition of adjuvant treatment.RESULTS: Overall, 894 patients were identified. Of these, 500 patients received PCRT. Adjuvant chemotherapy was delivered to 81.5% of the No-PCRT and 94.8% of the PCRT patients. Adjuvant radiotherapy was given to 29.4% of the patients in the No PCRT group. The 5-year RFS for the No-PCRT group was 92.6% for StageⅠ, 83.3% for Stage Ⅱ, and 72.9% for Stage Ⅲ. The 5-year RFS for the PCRT group was 95.2% for yp Stage 0, 91.7% for yp StageⅠ, 73.9% for yp Stage Ⅱ, and 50.7% for yp Stage Ⅲ.CONCLUSION: Pathologic stage can predict prognosis in PCRT patients. Five-year RFS is significantly lower among PCRT patients than No-PCRT patients in pathologic stage Ⅱ and Ⅲ. These results should be taken into account when considering adjuvant treatment for patients treated with PCRT.

Risk factors for postoperative recurrence after primary bowel resection in patients with Crohn's disease

AIM To evaluate the risk factors for postoperative recurrence after primary bowel resection in a cohort of Korean Crohn's disease(CD) patients.METHODS This study included 260 patients with no history of previous bowel surgery who underwent primary surgery for CD between January 2000 and December 2010 at Asan Medical Center(Seoul, South Korea). The median follow-up period was 101 mo.RESULTS During the follow-up period, 66 patients(25.4%) underwent a second operation for disease recurrence.At 1, 5 and 10 years after the first operation, the cumulative rate of surgical recurrence was 1.1%, 8.3% and 35.9% and clinical recurrence occurred in 1.2%, 23.6% and 68.1%, respectively. In multivariate analysis, undergoing an emergency operation was a significant risk factor for surgical recurrence-free survival(SRFS) [HR = 2.431, 95%CI: 1.394-4.240, P = 0.002], as were the presence of perianal disease after the first operation(HR = 1.715, 95%CI: 1.005-2.926, P = 0.048) and history of smoking(HR = 1.798, 95%CI: 1.088-2.969, P = 0.022). The postoperative use of antitumor necrosis factor(TNF) agents reduced SRFS risk(HR = 0.521, 95%CI: 0.300-0.904, P = 0.02).CONCLUSION History of smoking, postoperative perianal disease and undergoing an emergency operation were independent risk factors for surgical recurrence. Using anti-TNF agents may reduce surgical recurrence.

Isolated vaginal metastasis from stage Ⅰ colon cancer: A case report

BACKGROUND Distant metastasis occasionally occurs in patients who have been diagnosed with colorectal cancer(CRC), but it occurs in a few patients with stage I CRC. The vagina as a metastasis site has also been reported, albeit rarely. Most reported cases of vaginal metastasis(VM) report their origin from advanced CRC. We encountered a patient who was diagnosed with isolated VM originating from stage I colon cancer(T2N0) and herein present the case of this patient.CASE SUMMARY A 63-year-old woman visited the outpatient clinic because of a positive result from a stool occult blood test. She underwent laparoscopic anterior resection and was pathologically diagnosed with stage I(T2N0) sigmoid colon cancer. Neither lymphovascular invasion nor perineural invasion was observed. Ten months following the surgery, isolated vaginal metastases were detected on gynecologic examination. The examination was performed due to vaginal spotting. A transvaginal wide excision was performed, and no other adjuvant treatment was provided after discussion with a multidisciplinary team and the patient.Subsequently, a new VM was discovered after 33 mo. An additional transvaginal excision was performed. To date, there has been no evidence of further disease progression. From the time of diagnosis of VM, the patient’s overall survival has been 54 mo.CONCLUSION VM can occur as a result of early-stage colorectal cancer. Surgeons should consider the possibility of VM following complaints of gynecologic symptoms following surgery.

Postoperative changes of manometry after restorative proctocolectomy in Korean ulcerative colitis patients

To investigate the changes of postoperative anal sphincter function and bowel frequency in Korean patients with ulcerative colitis (UC). METHODSA total of 127 patients with UC who underwent restorative proctocolectomy (RPC) during 20 years were retrospectively analyzed. The parameters of anal manometry and bowel frequency were compared according to the 6-mo intervals until 24 mo postoperatively. Manometry was used to measure the maximal squeezing pressure (MSP) and maximal resting pressure (MRP). RESULTSMSP decreased after surgery until 6 mo (157 to 142 mmHg); thereafter, it improved and was recovered to and maintained at the preoperative value at 12 mo postoperatively (142-170 mmHg, P < 0.001). Although the decreased MRP (65 to 56 mmHg) improved after 18 mo (62 mmHg), it did not completely recover to the preoperative value. The decreased rectal capacity after surgery (90 to 82 mL) gradually increased up to 150 mL at 24 mo. Although bowel frequency showed significant gradual decreases at each interval, it was stabilized after 12 mo postoperatively (6.5 times/d). CONCLUSIONPostoperative changes of manometry and bowel frequency after restorative proctocolectomy in Korean patients with UC were not different from those in Western patients with UC.

Analysis of microsatellite instability in stool DNA of patients with colorectal cancer using denaturing high performance liquid chromatography

AIM： To evaluate the usefulness of denaturing high performance liquid chromatography （DHPLC） for analyzing microsatellite instability （MSI） status in stool DNA of patients with colorectal cancer. METHODS： A total of 80 cancer tissues from patients with primary sporadic colorectal tumor （proximal cancer： 27, distal cancer： 53） and matched stool （which were employed for comparison with the tissues） were analyzed for MSI status in BAT 26. DNA samples extracted from stool were evaluated by nested polymerase chain reaction （PCR） and DHPLC for MSI analysis. RESULTS： Six cases （7.5%） of MSI were identified in BAT 26 from 80 cancer tissues. All the stool DNA samples from patients whose cancer tissue showed IVlSI also displayed MSI in BAT 26. CONCLUSION： As MSI is one of the established fecal DNA markers to screen colorectal cancer, we propose to use DHPLC for the IVlSI analysis in fecal DNA.

Cumulative incidence and risk factors for pouch adenomas associated with familial adenomatous polyposis following restorative proctocolectomy

BACKGROUND The emergence of restorative total proctocolectomy has significantly reduced the lifetime colorectal cancer risk associated with familial adenomatous polyposis(FAP).However,adenomas may develop in the ileal pouch over time and may even progress to carcinoma.We evaluated the cumulative incidence,time to development,and risk factors associated with ileal pouch adenoma.AIM To evaluate the cumulative incidence,time to development,and risk factors associated with pouch adenoma.METHODS In this retrospective,observational study conducted at a tertiary center,95 patients with FAP who underwent restorative proctocolectomy at our center between 1989 and 2018 were consecutively included.The mean follow-up period was 88 mo.RESULTS Pouch adenomas were found in 24(25.3%)patients,with a median time of 52 mo to their first formation.Tubular adenomas were detected in most patients(95.9%).There were no high-grade dysplasia or malignancies.Of the 24 patients with pouch adenomas,13 had all detected adenomas removed.Among the 13 patients who underwent complete adenoma removal,four(38.5%)developed recurrence.Among 11(45.8%)patients with numerous polyps within the pouch,seven(63.6%)exhibited progression of pouch adenoma.The cumulative risks of pouch adenoma development at 5,10,and 15 years after pouch surgery were 15.2%,29.6%,and 44.1%,respectively.Severe colorectal polyposis(with more than 1000 polyps)was a significant risk factor for pouch adenoma development(hazard ratio,2.49;95% confidence interval:1.04-5.96;P=0.041).CONCLUSION Pouch adenomas occur at a fairly high rate in association with FAP after restorative proctocolectomy,and a high colorectal polyp count is associated with pouch adenoma development.

Cost-effective screening using a two-antibody panel for detecting mismatch repair deficiency in sporadic colorectal cancer

BACKGROUND The microsatellite instability(MSI)test and immunohistochemistry(IHC)are widely used to screen DNA mismatch repair(MMR)deficiency in sporadic colorectal cancer(CRC).For IHC,a two-antibody panel of MLH1 and MSH2 or four-antibody panel of MLH1,MSH2,PMS2,and MSH6 are used.In general,MSI is known as a more accurate screening test than IHC.AIM To compare two-and four-antibody panels of IHC in terms of accuracy and cost benefit on the basis of MSI testing for detecting MMR deficiency.METHODS We retrospectively analyzed patients with CRC who underwent curative surgery between 2015 and 2017 at a tertiary referral center.Both IHC with four antibodies and MSI tests were routinely performed.The sensitivity and specificity of a fourand two types of two-antibody panels(PMS2/MSH6 and MLH1/MSH2)were compared on the basis of MSI testing for detecting MMR deficiency.RESULTS High-frequency MSI was found in 5.5%(n=193)of the patients(n=3486).The sensitivities of the four-and two types of two-antibody panels were 97.4%,92.2%,and 87.6%,respectively.The specificities of the three types of panels did not differ significantly(99.6%for the four-antibody and PMS2/MSH6 panels,99.7%for the MLH1/MSH2 panel).Based on Cohen's kappa statistic(κ),four-and twoantibody panels were in almost perfect agreement with the MSI test(κ>0.9).The costs of the MSI test and the four-and two-antibody panels of IHC were approximately$200,$160,and$80,respectively.CONCLUSION Considering the cost of the four-antibody panel IHC compared to that of the twoantibody panel IHC,a two-antibody panel of PMS2/MSH6 might be the best choice in terms of balancing cost-effectiveness and accuracy.

Evaluating the benefit of adjuvant chemotherapy in patients with ypT0-1 rectal cancer treated with preoperative chemoradiotherapy

BACKGROUND Adjuvant chemotherapy(ACTx)is recommended in rectal cancer patients after preoperative chemoradiotherapy(PCRT),but its efficacy in patients in the early post-surgical stage who have a favorable prognosis is controversial.AIM To evaluate the long-term survival benefit of ACTx in patients with ypT0–1 rectal cancer after PCRT and surgical resection.METHODS We identified rectal cancer patients who underwent PCRT followed by surgical resection at the Asan Medical Center from 2005 to 2014.Patients with ypT0–1 disease and those who received ACTx were included.The 5-year overall survival(OS)and 5-year recurrence-free survival(RFS)were analyzed according to the status of the ACTx.RESULTS Of 520 included patients,413 received ACTx(ACTx group)and 107 did not(no ACTx group).No significant difference was observed in 5-year RFS(ACTx group,87.9%vs no ACTx group,91.4%,P=0.457)and 5-year OS(ACTx group,90.5%vs no ACTx group,86.2%,P=0.304)between the groups.cT stage was associated with RFS and OS in multivariate analysis[hazard ratio(HR):2.57,95%confidence interval(CI):1.07–6.16,P=0.04 and HR:2.27,95%CI:1.09–4.74,P=0.03,respectively].Furthermore,ypN stage was associated with RFS and OS(HR:4.74,95%CI:2.39–9.42,P<0.00 and HR:4.33,95%CI:2.20–8.53,P<0.00,respectively),but only in the radical resection group.CONCLUSION Oncological outcomes of patients with ypT0–1 rectal cancer who received ACTx after PCRT showed no improvement,regardless of the radicality of resection.Further trials are needed to evaluate the efficacy of ACTx in these group of patients.

Optimal postoperative surveillance strategies for stage III colorectal cancer

BACKGROUND Optimal surveillance strategies for stage III colorectal cancer(CRC)are lacking,and intensive surveillance has not conferred a significant survival benefit.AIM To examine the association between surveillance intensity and recurrence and survival rates in patients with stage III CRC.METHODS Data from patients with pathologic stage III CRC who underwent radical surgery between January 2005 and December 2012 at Asan Medical Center,Seoul,Korea were retrospectively reviewed.Surveillance consisted of abdominopelvic computed tomography(CT)every 6 mo and chest CT annually during the 5 year follow-up period,resulting in an average of three imaging studies per year.Patients who underwent more than the average number of imaging studies annually were categorized as high intensity(HI),and those with less than the average were categorized as low intensity(LI).RESULTS Among 1888 patients,864(45.8%)were in HI group.Age,sex,and location were not different between groups.HI group had more advanced T and N stage(P=0.002,0.010,each).Perineural invasion(PNI)was more identified in the HI group(21.4%vs 30.3%,P<0.001).The mean overall survival(OS)and recurrence-free interval(RFI)was longer in the LI group(P<0.001,each).Multivariate analysis indicated that surveillance intensity[odds ratio(OR)=1.999;95%confidence interval(CI):1.680–2.377;P<0.001],pathologic T stage(OR=1.596;95%CI:1.197–2.127;P=0.001),PNI(OR=1.431;95%CI:1.192–1.719;P<0.001),and circumferential resection margin(OR=1.565;95%CI:1.083–2.262;P=0.017)in rectal cancer were significantly associated with RFI.The mean post-recurrence survival(PRS)was longer in patients who received curative resection(P<0.001).Curative resection rate of recurrence was not different between HI(29.3%)and LI(23.8%)groups(P=0.160).PRS did not differ according to surveillance intensity(P=0.802).CONCLUSION Frequent surveillance with CT scan do not improve OS in stage III CRC patients.We need to evaluate role of other surveillance method rather than frequent CT scans to detect recurrence for which curative treatment was possible because curative resection is the important to improve post-recurrence survival.