Preoperative sarcopenia is a poor prognostic factor in lower rectal cancer patients undergoing neoadjuvant chemoradiotherapy: a retrospective study.

BACKGROUND: This study aimed to investigate the effect of sarcopenia on the prognosis of advanced lower rectal cancer patients receiving neoadjuvant chemoradiotherapy (CRT). Sarcopenia has been recognized as an adverse factor for surgical outcomes in several malignancies. However, the impact of preoperative sarcopenia on rectal cancer patients receiving CRT is still unknown. METHODS: This retrospective study included cT3-T4 anyN M0 lower rectal cancer patients who underwent CRT followed by R0 resection at our institution between October 2003 and December 2016. CRT consisted of 5-fluorouracil-based oral chemotherapy and long course radiation (50.4 Gy/28 fr). The psoas muscle area at the third lumbar vertebra level was evaluated by computed tomography before and after CRT, and was adjusted by the square of the height to obtain the psoas muscle mass index (PMI). Sarcopenia was defined as the sex-specific lowest quartile of the PMI. We assessed the association between pre- and post-CRT sarcopenia and postoperative prognosis. RESULTS: Among 234 patients, 55 and 179 patients were categorized as sarcopenia and non-sarcopenia patients, respectively. Although post-CRT sarcopenia correlated with residual tumor size, it had no association with other pathological features. The median follow-up period was 72.9 months, and the 5-year DFS and OS were 67.0% and 85.8%, respectively. Multivariate analysis showed that post-CRT sarcopenia was independently associated with poor DFS (HR: 1.76; P = 0.036), OS (HR: 2.01; P = 0.049), and recurrence in the liver (HR: 3.01; P = 0.025). CONCLUSIONS: Sarcopenia is a poor prognostic indicator in lower advanced rectal cancer patients treated with CRT.

Vascular anatomy of the splenic flexure: a review of the literature.

Surgical treatment of the transverse colon is difficult because of the many variations of blood vessels. We reviewed the patterns of vascular anatomy and the definition of the vessels around the splenic flexure. We searched the PubMed database for studies on the vascular anatomy of the splenic flexure that were published from January 1990 to October 2020. After screening of full texts, 33 studies were selected. The middle colic arteries were reported to arise independently without forming a common trunk in 8.9-33.3% of cases. The left colic artery was absent in 0-7.5% of cases. The accessory middle colic artery was present in 6.7-48.9% of cases and was present in > 80% of cases without a left colic artery. The reported frequency of Riolan's arch was 7.5-27.8%. The frequency was found to vary widely across studies, partially due to the ambiguous definition of Riolan's arch. A comprehensive preoperative knowledge of the branching patterns of the middle colic artery and left colic artery and the presence of collateral arteries would be helpful in surgery for colon cancer in the splenic flexure.

Hazard function analysis of metastatic recurrence after colorectal cancer surgery-A nationwide retrospective study.

BACKGROUND AND OBJECTIVES: An optimal postoperative surveillance protocol for colorectal cancer (CRC) is dependent on understanding the time line of recurrence. By hazard function analysis, this study aimed at evaluating the time of occurrence of metastasis. METHODS: A total of 21,671 Stage I-III colon cancer patients were retrospectively included from the Japanese study group for postoperative follow-up of colorectal cancer database. RESULTS: The 5-year incidence by metastasized organ was 6.3% for liver (right:left = 5.5%:7.0%, p = .0067), 6.0% for lung (right:left:rectum = 3.7%:4.4%:8.8%, p = 7.05E-45), and 2.0% for peritoneal (right:left:rectum = 3.1%:2.0%:1.2%, p = 1.29E-12). The peak of liver metastasis hazard rate (HR) (0.67 years) was earlier and higher than those of other metastases. The peak HR tended to be delayed in early stage CRCs (0.91, 0.76, and 0.52 years; for Stages I, II, and III, respectively). When analyzed as per the primary tumor location (right-sided, left-sided, and rectum), the peak HR for lung metastasis was twice as high for rectal cancer than for colon cancer, and peritoneal metastasis had a high HR in right-sided colon cancers. CONCLUSION: The time course for the risk of recurrence in various metastatic organs based on the primary tumor site was clearly visualized in this study. This will aid in individualizing postoperative surveillance schedules.

Therapeutic effects and limitations of chemoradiotherapy in advanced lower rectal cancer focusing on T4b.

PURPOSE: This study aimed to elucidate the benefits and limitations of preoperative chemoradiotherapy (CRT) in rectal cancer treatment, specifically in T4b rectal cancer. METHODS: This retrospective cohort study reviewed 1014 consecutive patients with clinical T3/4a/T4b adenocarcinomas of the lower rectum, who underwent total mesorectal excision at the Department of Surgical Oncology of the University of Tokyo Hospital and 22 referral institutions affiliated with the Japanese Study Group for Postoperative Follow-up of Colorectal Cancer. Patients were divided into two cohorts: cohort 1 comprised 298 consecutive patients who underwent CRT followed by radical surgery and cohort 2 comprised 716 consecutive patients who underwent curative surgery without preoperative therapy. We assessed the prognostic differences between the two cohorts, focusing particularly on T stages. RESULTS: In T3/4a patients, cohort 1 showed a significantly lower local recurrence rate than cohort 2 (4.8% vs. 9.4%, p=0.024), but not in T4b patients (23.5% vs. 16.0%, p=0.383). In contrast, no significant differences in survival were observed between T3/4a and T4b patients. T4b classification was found to be an independent predictive factor of local recurrence in cohort 1, but not in cohort 2. CONCLUSION: In T4b rectal cancer, preoperative CRT demonstrated a limited benefit for local control and survival. In cases of suspected T4b rectal tumors, additional therapies such as induction chemotherapy to conventional CRT may contribute to better outcomes.

Therapeutic significance of D3 dissection for low rectal cancer: a comparison of dissections between the lateral pelvic lymph nodes and the lymph nodes along the root of the inferior mesenteric artery in a multicenter retrospective cohort study.

PURPOSE: D3 dissection is the standard treatment modality for locally advanced low rectal cancer in Japan. The benefit of lateral pelvic lymph node (LPLN) dissection (LPLND) and lymph nodes along the root of inferior mesenteric artery (253 LN) dissection (253 LND) for low rectal cancer has often been studied separately, and few studies have investigated their benefit in the same cohort. This study aimed to clarify the therapeutic significance of dissection of the LPLN in comparison to that of dissection of the 253 LN for low rectal cancer. METHODS: We retrospectively evaluated 3508 patients with treatment-naïve stage I-III low rectal cancer who underwent mesorectal excision between 1997 and 2012. They were identified from the Japanese Study Group for Postoperative Follow-Up of Colorectal Cancer database. The rates of metastasis, survival, and therapeutic value index (5-year overall survival (OS) rate multiplied by metastatic rate for lymph node metastasis) were compared between LPLN and 253 LN. RESULTS: The rates of LPLN metastasis and 253 LN metastasis were 17.9% and 1.5%, respectively. The 5-year OS was significantly different between patients with and without LPLN metastasis (55.0% vs 85.5%, P < 0.0001) and between patients with and without 253 LN metastasis (36.2% vs 83.3%, P < 0.0001). The therapeutic value indexes of LPLN and 253 LN were 9.85 and 0.54, respectively. CONCLUSIONS: LPLND may have more therapeutic value than 253 LND for patients with treatment-naïve low rectal cancer, although both the patients with LPLN metastasis and those with 253 LN metastasis remained to have poor prognosis.

Prognostic Impact and Clinicopathological Features of Multiple Colorectal Cancers and Extracolorectal Malignancies: A Nationwide Retrospective Study.

INTRODUCTION: Multiple primary malignancies (MPMs) are likely to develop in patients with colorectal cancer (CRC); however, their prognoses are unclear. This study aims to investigate the prognostic impacts and clinicopathological features of multiple CRCs and extracolorectal malignancies (EMs) with CRC. METHODS: We retrospectively evaluated a total of 22,628 patients with stage I-III CRC who underwent curative resection at 24 referral institutes in Japan between January 2004 and December 2012. MPMs were classified as synchronous CRCs (SCRCs), metachronous CRCs, synchronous EMs (SEMs), and metachronous EMs. RESULTS: The presence of SCRCs (odds ratio 1.54, p < 0.001) was independently associated with SEMs in the multivariate analyses. SEMs were the strongest poor prognostic factor for OS (hazard ratio [HR] 2.21, p < 0.001) and RFS (HR 1.69, p < 0.001) compared with age, sex, and primary T and N factors. The incidence of stomach cancer was the highest in EMs, followed by lung, breast, and prostate cancers. Multiple CRCs were evenly distributed throughout the right-side colon to the rectum. DISCUSSION/CONCLUSION: SEMs were a strong poor prognostic factor for patients with stage I-III CRC. Patients with CRC, particularly those with SCRCs, should be surveyed for SEMs, especially for stomach and lung cancers.

Liver Injury Among Japanese Patients Treated Using Prophylactic Enoxaparin After Colorectal Surgery.

BACKGROUND: Enoxaparin, a low molecular weight heparin, has been used to prevent thrombotic events during major surgery without increasing the rate of hemorrhage. On the other hand, it was reported to cause liver injury, but the details of liver injury induced by prophylactic enoxaparin after abdominal surgery remain unclear. AIMS: This study aimed to clarify the relationship between prophylactic enoxaparin and liver injury after colorectal surgery, and characterize the injury profile. METHODS: We retrospectively reviewed 732 Japanese patients who underwent elective resection of the colorectum, and compared their clinicopathological background, details of surgery, postoperative complications, including liver injury, and the type of liver injury according to prophylactic use of enoxaparin. Univariate and multivariate analyses were performed to identify risk factors for liver injury during the postoperative period. RESULTS: The rate of liver injury was 8.9% for patients treated by prophylactic enoxaparin and 1.4% for those who did not receive enoxaparin after colorectal surgery (p < 0.0001). The median onset of liver injury among patients receiving enoxaparin was seven days, and the majority demonstrated the hepatocellular pattern. Enoxaparin was one of the independent risk factors for postoperative liver injury by multivariate analysis (odds ratio: 7.63, p < 0.0001). CONCLUSIONS: Prophylactic use of enoxaparin markedly increased the rate of postoperative liver injury in patients who underwent colorectal surgery. Our study confirmed that close monitoring of liver function parameters is essential for patients receiving enoxaparin during the postoperative period.

Low preoperative maximum squeezing pressure evaluated by anorectal manometry is a risk factor for non-reversal of diverting stoma.

PURPOSE: A diverting stoma is created to prevent anastomotic leakage and related complications impairing sphincteric function in rectal surgery. However, diverting stoma may be left unclosed. This study is aimed to analyze preoperative factors including anorectal manometric data associated with diverting stoma non-reversal before rectal surgery. We also addressed complications related to diverting stoma in patients undergoing surgery for rectal malignant tumor. METHODS: A total of 203 patients with rectal malignant tumor who underwent sphincter-preserving surgery with diverting stoma were retrospectively evaluated. The risk factors for non-reversal of diverting stoma were identified by univariate and multivariate analyses. For these analyses, anorectal manometric data were measured before rectal surgery. The association between stoma-related complications and other clinicopathological features was also analyzed. RESULTS: During the median follow-up of 46.4 months, 24% (49 patients) did not undergo stoma reversal. Among parameters that were available before rectal surgery, age ≥ 75 years, albumin < 3.5 g/dl, tumor size ≥ 30 mm, tumor distance from the anal verge < 4 cm, and maximum squeezing pressure (MSP) < 130 mmHg measured by anorectal manometry (ARM) were independent factors associated with stoma non-reversal. The most common stoma-related complication was peristomal skin irritation (25%). Ileostomy was the only factor associated with peristomal skin irritation. CONCLUSION: The current study demonstrated that low preoperative MSP evaluated by ARM, old age, hypoalbuminemia, and a large tumor close to the anus were predictive of diverting stoma non-reversal. Stoma site should be well deliberated when patients have the aforementioned risk factors for diverting stoma non-reversal.

Less intensive surveillance after radical surgery for stage I-III colorectal cancer by focusing on the doubling time of recurrence.

PURPOSE: To propose a new and improved surveillance schedule for colorectal cancer (CRC) patients by focusing on the recurrence rate, resectability, and especially, the tumor doubling time (DT) of recurrent tumors. METHODS: The subjects of this retrospective review were 1774 consecutive patients who underwent radical surgery for stage I-III CRC between January, 2004 and December, 2015. We calculated the DT by measuring the tumor diameter using computed tomography (CT). RESULTS: The median DT for recurrences in the liver, lung, peritoneum, and other locations were 35, 72, 85, and 36 days, respectively, (p < 0.001) and tumor growth rates differed according to the organs where recurrence developed. Multiple linear regression analysis showed that the DT was strongly associated with the relapse-free interval from primary surgery (p < 0.001), and that the DT in patients with recurrence detected ≥ 3 years after primary surgery was longer by 151.1 days than that in patients with recurrence detected within 1 year after primary surgery. We proposed a less intensive surveillance, which achieved an average cost reduction of 32.5% compared with conventional surveillance in Japan. CONCLUSION: We propose a new and more cost-efficient surveillance schedule for CRC surgery patients in the clinical setting.

Metastatic role of mammalian target of rapamycin signaling activation by chemoradiotherapy in advanced rectal cancer.

Postoperative distant metastasis dramatically affects rectal cancer patients who have undergone neoadjuvant chemoradiotherapy (NACRT). Here, we clarified the association between NACRT-mediated mammalian target of rapamycin (mTOR) signaling pathway activation and rectal cancer metastatic potential. We performed immunohistochemistry for phosphorylated mTOR (p-mTOR) and phosphorylated S6 (p-S6) on surgical specimen blocks from 98 rectal cancer patients after NACRT (cohort 1) and 80 colorectal cancer patients without NACRT (cohort 2). In addition, we investigated the association between mTOR pathway activity, affected by irradiation, and the migration ability of colorectal cancer cells in vitro. Based on the results of the clinical study, p-mTOR was significantly overexpressed in cohort 1 (with NACRT) as compared to levels in cohort 2 (without NACRT) (P < .001). High p-mTOR and p-S6 levels correlated with the development of distant metastasis only in cohort 1. Specifically, high p-S6 expression (HR 4.51, P = .002) and high pathological T-stage (HR 3.73, P = .020) after NACRT were independent predictors of the development of distant metastasis. In vitro, p-S6 levels and migration ability increased after irradiation in SW480 cells (TP53 mutation-type) but decreased in LoVo cells (TP53 wild-type), suggesting that irradiation modulates mTOR signaling and migration through cell type-dependent mechanisms. We next assessed the expression level of p53 by immunostaining in cohort 1 and demonstrated that p-S6 was overexpressed in samples with high p53 expression as compared to levels in samples with low p53 expression (P = .008). In conclusion, p-S6 levels after NACRT correlate with postoperative distant metastasis in rectal cancer patients, suggesting that chemoradiotherapy might modulate the mTOR signaling pathway, promoting metastasis.

Percutaneous Gastrojejunostomy Catheter Placement Using a Slow-Leak Balloon through the Reconstructed Gastric Tube after Esophagectomy.

Twelve patients who had undergone esophageal reconstruction because of cancer and in whom conventional percutaneous radiologic or endoscopic gastrostomy was considered difficult are reported. These patients underwent placement of a percutaneous gastrojejunostomy catheter through the reconstructed gastric tube using a slow-leak balloon that had been developed for percutaneous transesophageal gastrotubing. Retrospective evaluation showed successful outcomes without severe complications in all patients. Eight (66.6%) were able to resume oral intake, which allowed gastrojejunostomy catheter withdrawal in 3 (25%). This technique is feasible with acceptable clinical outcomes for patients who have undergone gastric tube reconstruction after esophagectomy.

Postoperative chemotherapy is associated with prognosis of stage IV colorectal cancer treated with preoperative chemotherapy/chemoradiotherapy and curative resection.

PURPOSE: Advances in systemic chemotherapy have increased the resectability in colorectal cancer (CRC) associated with metastases even if it was initially unresectable. However, what determines the prognosis of stage IV CRC patients treated by preoperative therapy and surgery remains unclear. We attempted to identify prognostic factors in such CRC patients. METHODS: We reviewed stage IV CRC patients who underwent curative resection between December 2007 and May 2019. The patients who underwent conversion chemotherapy for initially unresectable disease and those who received neoadjuvant chemotherapy (NAC) for resectable synchronous metastases or neoadjuvant chemoradiotherapy (NACRT) for advanced lower rectal cancer with resectable metastases were included. Recurrence-free survival (RFS) and overall survival (OS) were examined by multivariate analyses using Cox proportional hazard models. The RFS and OS curves were analyzed according to postoperative adjuvant chemotherapy (AC). RESULTS: Among 70 patients who underwent curative surgery (34 men, mean age: 60 years old), 33 had initially unresectable disease, 23 received NAC, and 14 NACRT. By multivariate analyses, AC was an independent predictor for improved RFS and OS (hazard ratio = 0.29, p = 0.0002, and hazard ratio = 0.37, p = 0.025). Patients treated with AC showed improved RFS and OS than those without AC (2-year RFS rate = 30% vs 19%, p = 0.031, and 3-year OS rate = 87% vs 67%, p = 0.045). CONCLUSION: Because of its association with improved prognosis, AC should be considered for stage IV CRC patients after curative resection regardless of initial resectability status and preoperative therapy.

Anastomotic bleeding following ileocolic end-to-side anastomosis using a circular stapler: incidence and risk factors.

PURPOSE: To identify the incidence of and risk factors for postoperative bleeding after ileocolic end-to-side anastomosis using a circular stapler. METHODS: We analyzed, retrospectively, the risk factors for postoperative anastomotic bleeding in patients who underwent right-sided colectomy with end-to-side anastomosis done using a circular stapler during colon tumor surgery at our institute between January 2015 and March 2019. RESULTS: Anastomotic bleeding developed in 10 (3.6%) of the total 279 patients. Univariate analysis revealed that age ≥ 80 years (8.8% vs. 1.9%; P = 0.008) and Eastern Cooperative Oncology Group performance status (ECOG PS) ≥ 1 (12.5% vs. 2.8%; P = 0.014) were significant risk factors for anastomotic bleeding. Postoperative anticoagulation therapy was not a risk factor for anastomotic bleeding. Multivariate analysis revealed that only age ≥ 80 years was an independent risk factor (odds ratio 4.12, 95% confidence interval 1.02-16.68, P = 0.047). Six of the ten patients with anastomotic bleeding were treated conservatively, three were treated by colonoscopic clipping, and one required surgery. CONCLUSION: End-to-side anastomosis is safe and feasible, but must be performed carefully in the elderly, who are at higher risk of anastomotic bleeding.

[Three Long-Surviving Cases of Recurrent Rectal Carcinomas Treated Non-Surgically and Cured].

Few cases of recurrent colorectal carcinomas were treated non-surgically and cured. Here, we report 3 such cases. Case No. 1 was of a 66-year-old woman, who underwent ISR for very low rectal cancer. Her disease Stage was tub2, T2N0M0. Two years and 6 months later, she developed intrapelvic recurrence involving sacral bones(S1-S3). Radiotherapy of 50 Gy followed by mFOLFOX6 with bevacizumab was administered for a year. She has been cancer-free for 6 years. Case No. 2 was of a 47-year-old man who underwent preoperative CRT of 40 Gy with 5-FU plus Leucovorin, and LAR was performed for very low rectal cancer. The disease Stage was tub2, T3N2M0. One year later, he was diagnosed with recurrent aortic lymph node metastasis. After 7 months of mFOLFOX6 with bevacizumab, he developed an anastomotic fistula. His chemotherapy was discontinued; he was cancer-free for 6 years. Case No. 3 was of a 56-year-old man who underwent TPE for low rectal cancer. The disease Stage was muc, T4b(urinary bladder)N0M1a(perianal skin). One year and 6 months later, he developed ileus and was diagnosed with intrapelvic recurrence. He underwent intestinal bypass operation, and CRT of 46 Gy with capecitabine was administered. He attained CR quickly, and was cancer-free for 5 years. Collecting similar cases to analyze the key to successful treatment is important.

[Three Long-Surviving Cases of Peritoneal Metastasis after Colorectal Cancer Resection].

We experienced 3 impressive colorectal cancer patients who developed peritoneal recurrences and underwent surgery several times and survived for more than 5 years. Case No. 1 was of a 44-year-old woman who underwent right hemicolectomy for her stage II A ascending colon cancer. She developed left ovarian metastasis, which was resected 3 years later. Five years later, she developed a pelvic peritoneal recurrence, which was resected successfully. Thirteen years later, she is doing well. Case No. 2 was of a 61-year-old man who underwent transverse colectomy for his stage II B colon cancer. He developed ileus 2 years 9 months later due to peritoneal recurrence, which was removed successfully. He underwent another resection for peritoneal metastasis 2 years 6 months later. He was administered 15 courses of FOLFOX6. He has remained cancer-free since 2009. Case No. 3 was of a 62-year-old man who underwent sigmoidectomy for his stage II A colon cancer. One year 8 months later, he underwent resection for a painful abdominal wall metastasis. Eight months later, he developed another abdominal wall recurrence, which was resected successfully. He underwent thoracoscopic resection 4 times for lung metastases and was given 16 courses of FOLFOX6. In 2009, he developed pelvic peritoneal nodules, which were resected. He later needed lymphadenectomy twice. He has remained cancer-free for the last 5 years and 6 months. Curative resection must be performed for a patient with peritoneal recurrence of colorectal cancer when surgery is indicated.

Angio-CT-Assisted Balloon Dissection: Protection of the Adjacent Intestine during Cryoablation for Patients with Renal Cancer.

The present study describes the technical feasibility of a combined-modality angiography/computed tomography (angio-CT)-assisted balloon dissection technique for bowel protection during renal cryoablation in six procedures in five patients. A retrospective review was performed to evaluate balloon dissection using the angio-CT system. Mean bowel-to-tumor distances before and after balloon dissection were 0.9 mm (range, 0-3 mm) and 13.0 mm (range, 11-17 mm), respectively. No bowel injury was observed during the mean follow-up period of 19 months (range, 7-44 mo). Our preliminary experience suggests that balloon dissection using the angio-CT system for bowel protection during renal cryoablation may be feasible and effective.

Incidence of neoplasias and effectiveness of postoperative surveillance endoscopy for patients with ulcerative colitis: comparison of ileorectal anastomosis and ileal pouch-anal anastomosis.

BACKGROUND: The incidence of neoplasia after surgery has not been sufficiently evaluated in patients with ulcerative colitis (UC), particularly in the Japanese population, and it is not clear whether surveillance endoscopy is effective in detecting dysplasia/cancer in the remnant rectum or pouch. The aims of this study were to assess and compare postoperative development of dysplasia/cancer in patients with UC who underwent ileorectal anastomosis (IRA) or ileal pouch-anal anastomosis (IPAA) and to evaluate the effectiveness of postoperative surveillance endoscopy. METHODS: One hundred twenty patients who received postoperative surveillance endoscopy were retrospectively reviewed for development of dysplasia/cancer in the remnant rectal mucosa or pouch. RESULTS: Three hundred seventy-nine endoscopy sessions were conducted for 30 patients after IRA, while 548 pouch endoscopy sessions were conducted for 90 patients after IPAA. In the IRA group, 5 patients developed dysplasia/cancer during postoperative surveillance and in all cases, neoplasia was detected at an early stage. In the IRA group, no patient developed neoplasia within 10 years of diagnosis; the cumulative incidence of neoplasia after disease onset was 7.2, 12.0, and 23.9% at 15, 20, and 25 years, respectively. In one case after stapled IPAA, dysplasia was found at the ileal pouch; a subsequent 9 endoscopy sessions in 8 years did not detect any dysplasia. Neoplasia was found more frequently during postoperative surveillance in the IRA group than in the IPAA group (p = .0028). The cumulative incidence of neoplasia after IRA was 3.8, 8.7, and 21.7% at 10, 15, and 20 years, respectively, and that after IPAA was 1.6% at 20 years. CONCLUSIONS: The cumulative incidence of neoplasia after IPAA was minimal. Those who underwent IRA had a greater risk of developing neoplasia than those who underwent IPAA, although postoperative surveillance endoscopy was able to detect dysplasia/cancer at an early stage. IRA can be the surgical procedure of choice only in selected cases in which it would be of benefit to the patient, with more careful surveillance.

Computed Tomography-guided Radiofrequency Ablation for Sub-diaphragm Hepatocellular Carcinoma: Safety and Efficacy of Inducing an Artificial Pneumothorax.

We retrospectively evaluated the safety and efficacy of artificial pneumothorax induction to perform computed tomography (CT)-guided radiofrequency ablation (RFA) for sub-diaphragm hepatocellular carcinomas (HCCs). From June 2008 to October 2010 at our institution, 19 HCCs (16 patients) were treated using CT-guided RFA after artificial pneumothorax induction. A 23-G needle was inserted into the liver surface at a site of 2 connected pleurae without lung tissue. After a small amount of air was injected, the pleural space widened, creating a small pneumothorax. Additional air was insufflated via a newly inserted 18-G cannula to raise the lung away from the planned puncture line for RFA. The electrode was then advanced transthoracically. Ablation was performed using a cool-tip electrode with manual impedance control mode. The injected air was then aspirated as much as possible. Artificial pneumothorax was successfully induced in all cases. The average total volume of injected air in each case was 238ml. No artificial pneumothorax-related complication occurred; lung injury occurred in one case during RF electrode insertion. No local progression occurred during follow-up. Recurring HCCs were observed in eight patients. Artificial pneumothorax induction is safe and effective for CT-guided RFA of sub-diaphragm HCCs, which are difficult to locate on US.

Surveillance colonoscopy for colitis-associated dysplasia and cancer in ulcerative colitis patients.

Long-standing ulcerative colitis patients are known to be at high risk for the development of colorectal cancer. Therefore, surveillance colonoscopy has been recommended for these patients. Because colitis-associated colorectal cancer may be difficult to identify even by colonoscopy, a random biopsy method has been recommended. However, the procedure of carrying out a random biopsy is tedious and its effectiveness has also not yet been demonstrated. Instead, targeted biopsy with chromoendoscopy has gained popularity in European and Asian countries. Chromoendoscopy is generally considered to be an effective tool for ulcerative colitis surveillance and is recommended in the guidelines of the British Society of Gastroenterology and the European Crohn's and Colitis Organisation. Although image-enhanced endoscopy, such as narrow-band imaging and autofluorescence imaging, has been investigated as a potential ulcerative colitis surveillance tool, it is not routinely applied for ulcerative colitis surveillance in its present form. The appropriate intervals of surveillance colonoscopy have yet to be determined. Although the Japanese and American guidelines recommend annual or biannual colonoscopy, the British Society of Gastroenterology and the European Crohn's and Colitis Organisation stratified their guidelines according to the risks of colorectal cancer. A randomized controlled trial comparing random and targeted biopsy methods has been conducted in Japan and although the final analysis is still ongoing, the results of this study should address this issue. In the present review, we focus on the current detection methods and characterization of dysplasia/cancer and discuss the appropriate intervals of colonoscopy according to the stratified risks.