Migrated coil and damaged stent removal during coil embolization, using an additional, retrievable stent: A case report

One of the common complications that can occur during coil embolization of cerebral aneurysms, is migration of coil lump alone. The removal of these migrated coils has been reported on a few occasions. On the other hand, rare complications would include the migration of the coil with subsequent stent dislocation. Currently, there is no standardized method to correct the complications of stent dislocation, and very few instances of this complication have been reported previously. In this report, we introduce a case of coil migration combined with stent dislocation. This occurred during coil embolization of an unruptured aneurysm of the distal, left internal carotid artery for a 52-year old woman. We retrieved both the damaged stent and migrated coil using another retrievable stent successfully with no more further complications. In the present report, we describe in detail how we corrected the complication successfully stent, and we discuss why this rescue maneuver is reasonable option for the complication mentioned above.

Could A1 Aplasia or Hypoplasia Affect the Morphology and Rupture Risk of Anterior Communicating Artery Aneurysm?

Objective@#: Anterior communicating artery (Acom) aneurysm is one of the most common intracranial aneurysms, constituting approximately 30–35% of all aneurysm formation in the brain. Anatomically, the H-complex (the anatomic morphology of both A1 to A2 segments) is thought to affects the nature of the Acom aneurysm due to its close relationship with the hemodynamics of the vessel. Therefore, we investigated the relative risk factors of aneurysmal rupture, especially focusing on H-complex morphology of the Acom. @*Methods@#: From January 2016 to December 2020, a total of 209 patients who underwent surgery, including clipping and coiling for Acom aneurysm in our institution were reviewed. There were 102 cases of ruptured aneurysm and 107 cases of unruptured aneurysm. The baseline morphology of aneurysms was investigated and the relationship between the H-complex and the clinical characteristics of patients with Acom aneurysms was assessed. @*Results@#: Of the 209 patients, 109 patients (52.1%) had symmetrical A1, 79 patients (37.8%) had unilateral hypoplastic A1, and 21 patients (10.0%) had aplastic A1. The hypoplastic A1 group and the aplastic A1 group were grouped together as unilateral dominancy of A1, and were compared with the symmetrical A1 group. There was no significant difference in demographic characteristics and radiological findings of Acom aneurysms between two groups. However, when dichotomizing the patients into ruptured cases and unruptured cases, unilateral dominance of the A1 segment was associated with aneurysmal rupture with statistical significance (p=0.011). @*Conclusion@#: These results suggest that the unilateral dominance of the A1 segment does not have a significant effect on the morphology of Acom aneurysms, but contributes to aneurysmal rupture. Thus, we can better understand the effects of hemodynamics on Acom aneurysm.

Initial local excision for clinical T1 rectal cancer showed comparable overall survival despite high local recurrence rate: a propensity-matched analysis

Purpose@#Local excision (LE) is an alternative initial treatment for clinical T1 rectal cancer, and has avoided potential morbidity. This study aimed to evaluate the clinical outcomes of LE compared with total mesorectal excision (TME) for clinical T1 rectal cancer. @*Methods@#Between January 2000 and December 2011, we retrospectively reviewed from multicenter data in patients with clinically suspected T1 rectal cancer treated with either LE or TME. Of 1,071 patients, 106 were treated with LE and 965 were treated with TME. The data were analyzed using propensity score matching, with each group comprising 91 patients. @*Results@#After propensity score matching, the median follow-up time was 60.8 months (range, 0.6–150.6 months). After adjustment for the necessary variables, patients who underwent LE showed a significantly higher local recurrence rate than did those who underwent TME; however, there were no differences in disease-free survival and overall survival. In the multivariate analysis, age (hazard ratio [HR], 9.620; 95% confidence interval [CI], 3.415–27.098; P<0.001) and angiolymphatic invasion (HR, 3.63; 95% confidence interval, 1.33–9.89; P=0.012) were independently associated with overall survival. However, LE was neither associated with overall survival nor disease-free survival. @*Conclusion@#LE for clinical T1 rectal cancer yielded a higher local recurrence rate than did TME. Nevertheless, LE provided comparable overall survival rate and can be proposed as an optional treatment in terms of organ-preserving strategies.

The risk of surgical site infection of oral sulfate tablet versus sodium picosulfate for bowel preparation in colorectal cancer surgery: a randomized clinical trial

Purpose@#Oral sulfate tablets are abundantly used for bowel preparation before colonoscopy. However, their efficiency and safety for bowel preparation before colorectal surgery remain ill-defined. Herein, we aimed to compare the surgical site infection rates and efficiency between oral sulfate tablets and sodium picosulfate. @*Methods@#We designed a prospective, randomized, phase 2 clinical trial. Patients with colorectal cancer aged 19–75 years who underwent elective bowel resection and anastomosis by minimally invasive surgery were administered oral sulfate tablets or sodium picosulfate. Eighty-three cases were analyzed from October 2020 to December 2021. Surgical site infection within 30 days after surgery was considered the primary endpoint. Postoperative morbidities, the degree of bowel cleansing, and tolerability were the secondary endpoints. @*Results@#Surgical site infection was detected in 1 patient (2.5%) in the oral sulfate tablet group and 2 patients (4.7%) in the sodium picosulfate group, indicating no significant difference between the 2 groups. Postoperative morbidity and the degree of bowel cleansing bore no statistically significant differences. Furthermore, none of the investigated tolerability criteria, namely bloating, pain, nausea, vomiting, and discomfort, differed significantly between the 2 groups. The patients’ willingness to reuse the drug was also not significantly different between the 2 groups. @*Conclusion@#Although we could not establish the noninferiority of oral sulfate tablets to sodium picosulfate, we found no evidence suggesting that oral sulfate tablets are less safe or tolerable than sodium picosulfate in preoperative bowel preparation.

Laparoscopic extended right hemicolectomy with superiorto-inferior dissection: a mentee’s initial experience

Laparoscopic right hemicolectomy is a widely accepted procedure for right colon cancer. Among the various approaches, the superior approach has potential benefits in that it exposes the gastrocolic trunk early and consistently allows for D3 lymph node dissection along superior mesenteric vessels. In this video, we present a beginner performing a laparoscopic extended right hemicolectomy using a superior approach without an assistant.

Comparison of patient-reported quality of life and functional outcomes following laparoscopic and transanal total mesorectal excision of rectal cancer

Purpose@#The effect of transanal total mesorectal excision (TaTME) on patients’ quality of life and functional outcomes is not fully understood. This study aimed to compare the quality of life and bowel, anorectal, and urogenital functions after laparoscopic and TaTME. @*Methods@#Laparoscopic or TaTME was performed for 202 propensity score-matched patient pairs with rectal cancer between January 2014 and December 2017 at the National Cancer Center, Korea. The outcomes for all patients were assessed using anorectal manometry, the European Organization for Research and Treatment of Cancer (EORTC) Core Quality of Life Questionnaire (QLQ-C30) and Colorectal Cancer-Specific Quality of Life Questionnaire (QLQ-CR38), low anterior resection syndrome (LARS) score, Fecal Incontinence Severity Index, and International Prostate Symptom Score (IPSS). This retrospective comparative study included patients who completed anorectal manometry and the questionnaires before treatment and at 1 year after surgery. @*Results@#The EORTC QLQ-C30 and QLQ-CR38 showed comparable outcomes regarding the quality of life in both groups. More patients experienced major LARS in the transanal group at 1 year postoperatively (31.0% vs. 6.8% in the laparoscopic group, P = 0.004). Multivariable analysis revealed no significant difference in the LARS score between the groups at 1 year postoperatively (odds ratio, 2.30; 95% confidence interval, 0.79–6.72; P = 0.127). Significant differences in the IPSS were not noted between the groups. @*Conclusion@#The quality of life and functional outcomes were comparable between the laparoscopic and transanal approaches; however, our findings suggest a higher rate of LARS after TaTME.

Diverting ileostomy itself may not increase the rate of postoperative readmission related to dehydration after low anterior resection

Purpose@#This study was performed to evaluate the risk of readmission in the first year after low anterior resection (LAR) for patients with rectal cancer and to identify the contributing factors for readmission related to dehydration specifically. @*Methods@#This was a retrospective analysis of 570 patients who underwent LAR for rectal cancer at National Cancer Center, Republic of Korea. A diverting loop ileostomy was performed in 357 (62.6%) of these patients. Readmission was defined as an unplanned visit to the emergency room or admission to the ward. The reasons for readmission were reviewed and compared between the ileostomy (n = 357) and no-ileostomy (n = 213) groups. The risk factors for readmission and readmission due to dehydration were analyzed using multivariable logistic and Cox proportional hazard model. @*Results@#Dehydration was the most common cause of readmission in both groups (ileostomy group, 6.7%, and no-ileostomy group, 4.7%, P = 0.323). On multivariable analysis, risk factors for readmission were an estimated intraoperative blood loss of ≥400 mL (odds ratio [OR], 1.757; 95% confidence interval [CI], 1.058–2.918; P = 0.029), and postoperative chemotherapy (OR, 2.914; 95% CI, 1.824–4.653; P < 0.001). On multivariable analysis, postoperative chemotherapy, and not a diverting loop ileostomy, was an independent risk factor for dehydration-related readmission (OR, 5.102; 95% CI, 1.772–14.688; P = 0.003). @*Conclusion@#The most common cause of readmission after LAR for rectal cancer was dehydration, as reported previously. Postoperative chemotherapy, not the creation of a diverting ileostomy, was identified as the risk factor associated with readmission related to dehydration.

Effect of lateral lymph node dissection on the quality of life and genitourinary function after neoadjuvant chemoradiotherapy for rectal cancer

Purpose@#This study was performed to evaluate the quality of life and genitourinary function after total mesorectal excision with lateral lymph node dissection compared to those after total mesorectal excision alone following neoadjuvant chemoradiotherapy for rectal cancer. @*Methods@#Among patients who underwent rectal cancer surgery after completing neoadjuvant chemoradiotherapy between September 2011 and October 2018 at the National Cancer Center, Korea, patients who completed the validated questionnaires before initiation of neoadjuvant chemoradiotherapy and at 3 months and 1 year postoperatively were included in this study. The European Organization for Research and Treatment of Cancer (EORTC) core quality of life questionnaire (QLQ-C30), colorectal cancer-specific quality of life questionnaire (QLQ-CR38), and International Prostate Symptom Score (IPSS) questionnaire were used for collecting data. @*Results@#The total mesorectal excision alone group and the total mesorectal excision with lateral lymph node dissection group included 52 and 38 patients, respectively. The second group included significantly younger patients (P = 0.024), had a higher incidence of clinical T4 stage disease (P = 0.033), estimated blood loss (P = 0.003), and longer operation time (P < 0.001). Significant differences were not observed between the groups with respect to the EORTC QLQ-C30, QLQ-CR38, and IPSS. Multivariable analysis showed that lateral lymph node dissection had no statistically significant association with postoperative urinary dysfunction (P = 0.953). @*Conclusion@#The overall quality of life and urinary function after total mesorectal excision does not differ significantly when lateral lymph node dissection is performed as well.

Comparison of patient-reported quality of life and functional outcomes following laparoscopic and transanal total mesorectal excision of rectal cancer

Purpose@#The effect of transanal total mesorectal excision (TaTME) on patients’ quality of life and functional outcomes is not fully understood. This study aimed to compare the quality of life and bowel, anorectal, and urogenital functions after laparoscopic and TaTME. @*Methods@#Laparoscopic or TaTME was performed for 202 propensity score-matched patient pairs with rectal cancer between January 2014 and December 2017 at the National Cancer Center, Korea. The outcomes for all patients were assessed using anorectal manometry, the European Organization for Research and Treatment of Cancer (EORTC) Core Quality of Life Questionnaire (QLQ-C30) and Colorectal Cancer-Specific Quality of Life Questionnaire (QLQ-CR38), low anterior resection syndrome (LARS) score, Fecal Incontinence Severity Index, and International Prostate Symptom Score (IPSS). This retrospective comparative study included patients who completed anorectal manometry and the questionnaires before treatment and at 1 year after surgery. @*Results@#The EORTC QLQ-C30 and QLQ-CR38 showed comparable outcomes regarding the quality of life in both groups. More patients experienced major LARS in the transanal group at 1 year postoperatively (31.0% vs. 6.8% in the laparoscopic group, P = 0.004). Multivariable analysis revealed no significant difference in the LARS score between the groups at 1 year postoperatively (odds ratio, 2.30; 95% confidence interval, 0.79–6.72; P = 0.127). Significant differences in the IPSS were not noted between the groups. @*Conclusion@#The quality of life and functional outcomes were comparable between the laparoscopic and transanal approaches; however, our findings suggest a higher rate of LARS after TaTME.

Diverting ileostomy itself may not increase the rate of postoperative readmission related to dehydration after low anterior resection

Purpose@#This study was performed to evaluate the risk of readmission in the first year after low anterior resection (LAR) for patients with rectal cancer and to identify the contributing factors for readmission related to dehydration specifically. @*Methods@#This was a retrospective analysis of 570 patients who underwent LAR for rectal cancer at National Cancer Center, Republic of Korea. A diverting loop ileostomy was performed in 357 (62.6%) of these patients. Readmission was defined as an unplanned visit to the emergency room or admission to the ward. The reasons for readmission were reviewed and compared between the ileostomy (n = 357) and no-ileostomy (n = 213) groups. The risk factors for readmission and readmission due to dehydration were analyzed using multivariable logistic and Cox proportional hazard model. @*Results@#Dehydration was the most common cause of readmission in both groups (ileostomy group, 6.7%, and no-ileostomy group, 4.7%, P = 0.323). On multivariable analysis, risk factors for readmission were an estimated intraoperative blood loss of ≥400 mL (odds ratio [OR], 1.757; 95% confidence interval [CI], 1.058–2.918; P = 0.029), and postoperative chemotherapy (OR, 2.914; 95% CI, 1.824–4.653; P < 0.001). On multivariable analysis, postoperative chemotherapy, and not a diverting loop ileostomy, was an independent risk factor for dehydration-related readmission (OR, 5.102; 95% CI, 1.772–14.688; P = 0.003). @*Conclusion@#The most common cause of readmission after LAR for rectal cancer was dehydration, as reported previously. Postoperative chemotherapy, not the creation of a diverting ileostomy, was identified as the risk factor associated with readmission related to dehydration.

The effect of curative resection on fecal microbiota in patients with colorectal cancer: a prospective pilot study

Purpose@#Although many studies have evaluated the association between intestinal microorganisms and the risk of colorectal cancer (CRC), only a few studies have investigated the changes in microorganisms following curative treatment for CRC. The current study analyzed changes in intestinal microbiota following curative surgery in CRC patients. @*Methods@#Stool samples were collected before and 6 months after surgery, from 11 patients with clinical stage III CRC, who underwent curative surgery between May 2017 and June 2017. Next, 16S rRNA gene sequencing was performed. Operational taxonomic units (OTUs) and alpha diversity were evaluated using the Shannon index. The bacterial compositions of the stools were analyzed according to taxonomic rank at genus and phylum levels. @*Results@#OTUs and alpha diversity were significantly decreased following surgery (P < 0.001 and P = 0.019, respectively). The compositions of several bacterial taxa changed after surgery. At genus level, proportions of pathogens such as Campylobacter, Fusobacterium, Haemophilus, Porphyromonas, and Prevotella, decreased after surgery (adjusted P < 0.05). At phylum level, the proportion of Fusobacteria decreased after surgery (adjusted P < 0.001). @*Conclusion@#Significant changes in intestinal microbial communities were noted following curative resection of CRC patients. Especially, decreases in pathogenic bacterial populations, such as Fusobacterium and Prevotella, which are known to be associated with CRC development, were detected even though OTUs and alpha diversity were decreased following curative resection. To determine and validate the clinical significance of these findings, large scale, prospective studies that include cancer prognoses are required.

Magnetic Resonance-Based Texture Analysis Differentiating KRAS Mutation Status in Rectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Mutation of the Kirsten Ras (KRAS) oncogene is present in 30%-40% of colorectal cancers and has prognostic significance in rectal cancer. In this study, we examined the ability of radiomics features extracted from T2-weighted magnetic resonance (MR) images to differentiate between tumors with mutant KRAS and wild-type KRAS. @*Materials and Methods@#Sixty patients with primary rectal cancer (25 with mutant KRAS, 35 with wild-type KRAS) were retrospectively enrolled. Texture analysis was performed in all regions of interest on MR images, which were manually segmented by two independent radiologists. We identified potentially useful imaging features using the two-tailed t test and used them to build a discriminant model with a decision tree to estimate whether KRAS mutation had occurred. @*Results@#Three radiomic features were significantly associated with KRASmutational status (p < 0.05). The mean (and standard deviation) skewness with gradient filter value was significantly higher in the mutant KRAS group than in the wild-type group (2.04±0.94 vs. 1.59±0.69). Higher standard deviations for medium texture (SSF3 and SSF4) were able to differentiate mutant KRAS (139.81±44.19 and 267.12±89.75, respectively) and wild-type KRAS (114.55±29.30 and 224.78±62.20). The final decision tree comprised three decision nodes and four terminal nodes, two of which designated KRAS mutation. The sensitivity, specificity, and accuracy of the decision tree was 84%, 80%, and 81.7%, respectively. @*Conclusion@#Using MR-based texture analysis, we identified three imaging features that could differentiate mutant from wild-type KRAS. T2-weighted images could be used to predict KRAS mutation status preoperatively in patients with rectal cancer.

Characteristics of minute T1 colorectal cancer in relevance to pathology and treatment

Purpose@#Minute T1 colorectal cancer (CRC) lesions (≤5 mm) are rare; however, little is known about their characteristics and aggressiveness. In this study, we evaluated the characteristics of minute T1 CRC in relevance to pathology and treatment. @*Methods@#This retrospective study included 849 patients with T1 CRC endoscopically or surgically treated between January 2001 and December 2016. The patients were stratified into 4 groups according to tumor size; minute group (≤5 mm), small group (6–10 mm), medium group (11–20 mm), and large group (≥21 mm). Clinicopathological variables were evaluated with respect to tumor size. @*Results@#The incidence of the minute T1 CRC was 2.4% (20 of 849). Minute T1 CRC was significantly associated with flat type (minute, 25%; small, 12.6%; medium, 8.8%; large, 12.6%; P = 0.016), right-sided cancer (30%, 15.4%, 15.4%, 15.1%, P = 0.002) and the absence of background adenoma (BGA) (50%, 40.7%, 32.8%, 18.1%, P < 0.001). In patients who underwent surgery, lymph node metastasis (LNM) was significantly higher in the minute group (36.4%, 15.9%, 15.7%, 9.2%, P = 0.029). @*Conclusion@#Minute T1 CRC is significantly associated with flat type, right-sided cancers, as well as with the absence of BGA and LNM. These results suggested the minute T1 CRC lesions are often aggressive and are likely to be missed during colonoscopy.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy With Mitomycin C Used for Colorectal Peritoneal Carcinomatosis

Purpose@#This study aimed to assess the evaluation of clinical outcomes and consequences of complications after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for the peritoneal carcinomatosis (PC) from colorectal cancer. @*Methods@#A total 26 patients underwent CRS and HIPEC for PC from colorectal cancer between March 2009 and April 2018. All the patients underwent CRS with the purpose of complete or near-complete cytoreduction. Intraoperative HIPEC was performed simultaneously after the CRS. Mitomycin C was used as chemotherapeutic agent for HIPEC. @*Results@#Median disease-free survival was 27.8 months (range, 13.4–42.2 months). Median overall survival was 56.0 months (range, 28.6–83.5 months). The mean peritoneal cancer index (PCI) was 8.73 ± 5.54. The distributions thereof were as follows: PCI <10, 69.23%; PCI 10–19, 23.08%; and PCI ≥20, 7.69%. The completeness of cytoreduction was 96.2% of patients showed CC-0, with 3.8% achieved CC-1. The mean operation time was 8.5 hours, and the mean postoperative hospital stay was 21.6 days. The overall rate of early postoperative complications was 88.5%; the rate of late complications was 34.6%. In the early period, most complications were grades I–II complications (65.4%), compared to grades III–V (23.1%). All late complications, occurring in 7.7% of patients, were grades III–V. There was no treatment-related mortality. @*Conclusion@#Although the complication rate was approximately 88%, but the rate of severe complication rate was low. In selective patients with peritoneal recurrence, more aggressive strategies for management, such as CRS with HIPEC, were able to be considered under the acceptable general condition and life-expectancy.

Small Bowel Perforation Associated With Gastrointestinal Graft-Versus-Host Disease and Cytomegalovirus Enteritis in a Patient With Leukemia: A Case Report With Literature Review

Gastrointestinal graft-versus-host disease (GVHD) is a common complication after hematopoietic stem cell transplantation. Concomitant cytomegalovirus (CMV) enteritis worsens the prognosis of this condition. We report a case of small bowel perforation associated with gastrointestinal GVHD and CMV enteritis in a patient with leukemia who was successfully treated surgically. A 39-year-old man presented with intestinal perforation necessitating emergency surgical intervention. He was diagnosed with T-cell acute lymphoblastic leukemia and developed severe gastrointestinal GVHD and CMV enteritis after hematopoietic stem cell transplantation. His terminal ileum showed a perforation with diffuse wall thinning, and petechiae were observed over long segments of the distal ileum and the proximal colon. Small bowel segmental resection and a subtotal colectomy with a double-barreled ileocolostomy were performed. The patient recovered uneventfully after the operation. Based on reports described in the literature, surgery plays a minor role in the management of gastrointestinal GVHD; however, timely surgical intervention could be effective in selected patients.

The effect of curative resection on fecal microbiota in patients with colorectal cancer: a prospective pilot study

Purpose@#Although many studies have evaluated the association between intestinal microorganisms and the risk of colorectal cancer (CRC), only a few studies have investigated the changes in microorganisms following curative treatment for CRC. The current study analyzed changes in intestinal microbiota following curative surgery in CRC patients. @*Methods@#Stool samples were collected before and 6 months after surgery, from 11 patients with clinical stage III CRC, who underwent curative surgery between May 2017 and June 2017. Next, 16S rRNA gene sequencing was performed. Operational taxonomic units (OTUs) and alpha diversity were evaluated using the Shannon index. The bacterial compositions of the stools were analyzed according to taxonomic rank at genus and phylum levels. @*Results@#OTUs and alpha diversity were significantly decreased following surgery (P < 0.001 and P = 0.019, respectively). The compositions of several bacterial taxa changed after surgery. At genus level, proportions of pathogens such as Campylobacter, Fusobacterium, Haemophilus, Porphyromonas, and Prevotella, decreased after surgery (adjusted P < 0.05). At phylum level, the proportion of Fusobacteria decreased after surgery (adjusted P < 0.001). @*Conclusion@#Significant changes in intestinal microbial communities were noted following curative resection of CRC patients. Especially, decreases in pathogenic bacterial populations, such as Fusobacterium and Prevotella, which are known to be associated with CRC development, were detected even though OTUs and alpha diversity were decreased following curative resection. To determine and validate the clinical significance of these findings, large scale, prospective studies that include cancer prognoses are required.

Nomogram Development and External Validation for Predicting the Risk of Lymph Node Metastasis in T1 Colorectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Predicting lymph node metastasis (LNM) risk is crucial in determining further treatment strategies following endoscopic resection of T1 colorectal cancer (CRC). This study aimed to establish a new prediction model for the risk of LNM in T1 CRC patients. MATERIALS AND METHODS: The development set included 833 patients with T1 CRC who had undergone endoscopic (n=154) or surgical (n=679) resection at the National Cancer Center. The validation set included 722 T1 CRC patients who had undergone endoscopic (n=249) or surgical (n=473) resection at Daehang Hospital. A logistic regression model was used to construct the prediction model. To assess the performance of prediction model, discrimination was evaluated using the receiver operating characteristic (ROC) curves with area under the ROC curve (AUC), and calibration was assessed using the Hosmer-Lemeshow (HL) goodness-of-fit test. RESULTS: Five independent risk factors were determined in the multivariable model, including vascular invasion, high-grade histology, submucosal invasion, budding, and background adenoma. In final prediction model, the performance of the model was good that the AUC was 0.812 (95% confidence interval [CI], 0.770 to 0.855) and the HL chi-squared test statistic was 1.266 (p=0.737). In external validation, the performance was still good that the AUC was 0.771 (95% CI, 0.708 to 0.834) and the p-value of the HL chi-squared test was 0.040. We constructed the nomogram with the final prediction model. CONCLUSION: We presented an externally validated new prediction model for LNM risk in T1 CRC patients, guiding decision making in determining whether additional surgery is required after endoscopic resection of T1 CRC.

Feasibility of transanal total mesorectal excision in cases with challenging patient and tumor characteristics

PURPOSE: To assess the feasibility of transanal total mesorectal excision in difficult cases including obese patients or patients with bulky tumors or threatened mesorectal fascias. METHODS: We performed laparoscopy-assisted transanal total mesorectal excision in patients with biopsy-proven rectal adenocarcinoma located 3–12 cm from the anal verge as part of a prospective, single arm, pilot trial. The primary endpoint was resection quality and circumferential resection margin involvement. Secondary endpoints included the number of harvested lymph nodes and 30-day postoperative complications. RESULTS: A total of 12 patients (9 men and 3 women) were enrolled: one obese patient, 7 with large tumors and 8 with threatened mesorectal fascias (4 patients had multiple indications). Tumors were located a median of 5.5 cm from the anal verge, and all patients received preoperative chemoradiotherapy. Median operating time was 191 minutes, and there were no intraoperative complications. One patient needed conversion to open surgery for ureterocystostomy after en bloc resection. Complete or near-complete excision and negative circumferential resection margins were achieved in all cases. The median number of harvested lymph nodes was 15.5. There was no postoperative mortality and 3 cases of postoperative morbidity (1 postoperative ileus, 1 wound problem near the stoma site, and 1 anastomotic dehiscence). CONCLUSION: This pilot study showed that transanal total mesorectal excision is also feasible in difficult laparoscopic cases such as in obese patients or those with bulky tumors or tumors threatening the mesorectal fascia. Additional larger studies are needed.

Colonoscopy learning curves for colorectal surgery fellow trainees: experiences with the 15-year colonoscopy training program

PURPOSE: This study aimed to analyze the learning curves for colorectal surgery fellows in a colonoscopy training program. METHODS: Between May 2003 and February 2017, 60 surgical fellows joined our 1-year colonoscopy training program as trainees and performed 43,784 cases of colonoscopy. All trainees recorded their colonoscopy experiences prospectively into the database. After excluding 6 trainees, who had experience with performing more than 50 colonoscopies before participating in our training program or who discontinued our training program with experience performing less than 300 colonoscopies, this study included 54 trainees who had performed 39,539 colonoscopy cases. We analyzed the cecal intubation rate (CIR) and cecal intubation time (CIT) using the cumulative sum (Cusum) technique and moving average method to assess the technical colonoscopy competence. RESULTS: Overall, the CIR by the trainees was 80.7%. The median number of cases of colonoscopy performed during the training period for each trainee was 696 (range, 322–1,669). The trainees were able to achieve a 90% CIR with 412 and 493 procedures when analyzed using the moving average and the Cusum, respectively. Using the moving average method, CIRs after 150, 300, and 400 procedures were 67.0%, 84.1%, and 89.2%, respectively. The CIT of trainees continuously decreased until 400 successful cases. Median CITs were 9.4, 8.3, and 7.4 minutes at 150, 300, and 400 successful cases, respectively. CONCLUSION: We found that more than 400 cases of experience were needed for technical competence in colonoscopy. Continuous teaching and monitoring is required until trainees become sufficiently competent.

Redefining the Positive Circumferential Resection Margin by Incorporating Preoperative Chemoradiotherapy Treatment Response in Locally Advanced Rectal Cancer: A Multicenter Validation Study / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: This study was conducted to validate the prognostic influence of treatment response among patients with positive circumferential resection margin for locally advanced rectal cancer. MATERIALS AND METHODS: Clinical data of 197 patientswith positive circumferential resection margin defined as ≤ 2 mm after preoperative chemoradiotherapy followed by total mesorectal excision between 2004 and 2009 were collected for this multicenter validation study. All patients underwent median 50.4 Gy radiation with concurrent fluoropyrimidine based chemotherapy. Treatment response was dichotomized to good response, including treatment response of grade 2 or 3, and poor response, including grade 0 or 1. RESULTS: After 52 months median follow-up, 5-year overall survival (OS) for good responders and poor responders was 79.1% and 48.4%, respectively (p < 0.001). In multivariate analysis, circumferential resection margin involvement and treatment response were a prognosticator for OS and locoregional recurrence-free survival. In subgroup analysis, good responders with close margin showed significantly better survival outcomes for survival. Good responders with involved margin and poor responders with close margin shared similar results, whereas poor responders with involved margin had worst survival (5-year OS, 81.2%, 57.0%, 50.0%, and 32.4%, respectively; p < 0.001). CONCLUSION: Among patients with positive circumferential resection margin after preoperative chemoradiotherapy, survival of the good responders was significantly better than poor responders. Subgroup analysis revealed that definition of positive circumferential resection margin may be individualized as involvement for good responders, whereas ≤ 2 mm for poor responders.