Gel immersion endoscopic mucosal resection for small gastric neoplastic lesions: A pilot study.

Gastric endoscopic mucosal resection is challenging due to the slippery mucosa, abundant blood vessels, and the presence of mucus. We developed gel immersion endoscopy to secure the visual field, even in a blood-filled gastrointestinal lumen in 2016. Clear gel with appropriate viscosity, instead of water, can prevent rapid mixture with blood and facilitate identification of the culprit vessel. We further optimized the gel for endoscopic treatment, and the resultant product, Viscoclear (Otsuka Pharmaceutical Factory) was first released in Japan in 2020. The viscosity of this gel has been optimized to maximize endoscopic visibility without compromising the ease of its irrigation. The aim of this study is to clarify the effectiveness of gel immersion endoscopic mucosal resection for small-sized early gastric neoplasms. Seven lesions in seven patients were treated by gel immersion endoscopic mucosal resection. The size of all lesions was under 10 mm. The median procedure time was 4.5 min. Intraoperative bleeding occurred in four of seven lesions immediately after snare resection and was easily controlled by endoscopic hemostatic forceps during the gel immersion endoscopy. The R0 resection rate was 100%. In conclusion, gel immersion endoscopic mucosal resection may be a straightforward, rapid, and safe technique for resecting superficial gastric neoplasms <10 mm in diameter.

Effect of early dose increase of evocalcet for intractable hypercalcemia caused by parathyroid carcinoma.

Summary: Hypercalcemia due to parathyroid carcinoma (PC) is safely and quickly controlled with rapidly increasing evocalcet doses. Most parathyroid carcinomas are detected because of hypercalcemia due to primary hyperparathyroidism (PHPT). Hypercalcemia becomes more severe in patients with PC than those with parathyroid adenoma or hyperplasia. Hypercalcemia often causes renal dysfunction, gastrointestinal symptoms, and psychiatric symptoms. Consequently, the serum calcium level needs to be promptly corrected. Here, we report a case of PC with remarkably persistent hypercalcemia, which we safely and quickly controlled with rapidly increasing evocalcet doses. A 77-year-old female presented with renal dysfunction. Her serum calcium (Ca) and intact parathyroid hormone serum levels were 13.9 mg/dL and 1.074 pg/mL, respectively. Her renal function worsened because of hypercalcemia due to PHPT. Technetium-99 m methoxy-isobutyl-isonitrile parathyroid scintigraphic examination revealed an accumulation below the right thyroid lobe. CT examination showed a 35-mm mass. Hypercalcemia needed to be immediately corrected because of the patient's worsening renal function. Evocalcet treatment at a gradually increasing dose of up to 20 mg over 3 weeks allowed her serum Ca level to be maintained below 11 mg/dL. Only mild nausea was observed at the beginning of the treatment. The mass was suspected as PC because the hypercalcemia was refractory to high-dose evocalcet. The patient was treated with parathyroidectomy and ipsilateral thyroidectomy. PC was diagnosed based on the pathological findings of capsular and venous invasion. The patient's renal function improved and surgery could be safely performed by promptly correcting hypercalcemia. Learning points: Hypercalcemia due to parathyroid carcinoma (PC) is often more severe than that caused by parathyroid adenoma or hyperplasia. PC is a rare disease, but it should be considered if the patient has intractable hypercalcemia due to primary hyperparathyroidism (PHPT). Evocalcet, which is used to treat hypercalcemia due to PHPT, does not interact with P450 (CYP) and causes few side effects. Complications, including renal dysfunction, were improved and the surgery could be safely performed by promptly correcting hypercalcemia. PC has a high recurrence rate. En-block excision is necessary when PC is suspected.

Changes in Lysophospholipid Components in Ulcerative Colitis and Colitis-associated Cancer.

BACKGROUND: In recent years, it has become clear that, in addition to normal cytokines, phospholipid mediators play an important role in the development, growth, infiltration, and metastasis of cancer and in the cancer microenvironment. A phospholipid analysis method using tandem mass spectrometry (LC-MS/MS) with high detection sensitivity has enabled quantification of phospholipids, even when using a very small sample. To date, we had applied this MS technology to colorectal cancer tissue. Therefore, in this study, this mass spectrometry technique was applied to ulcerative colitis (UC) and UC-related colorectal cancer, and an analysis was conducted with the aim of clarifying which lysophospholipids specifically change in each type of tissue. MATERIALS AND METHODS: UC-associated colorectal cancer tissue and UC mucosa were collected from surgical specimens of colitic cancer (n=3). Cancerous and non-cancerous tissues were collected from surgical specimens from patients with sporadic colorectal cancer (n=11). After extraction from these tissues, the amounts of lysophospholipids were quantified by LC-MS/MS. In addition, lysophosphatidylserine (LPS) and lysophosphatidylinositol (LPI) were quantified for each molecular species of fatty acids. RESULTS: Compared to normal mucosa, LPI was increased 3.8-fold (p<0.001) and LPS 3.5-fold (p<0.001) in UC-related colorectal cancer. Molecular species of LPI which were increased in UC-related colorectal cancer were 18:0 (p=0.001), 16:0 (p=0.03) and 20:4 (p=0.004), and of LPS were 18:0 (p<0.001) and 22:6 (p=0.014). CONCLUSION: Lysophospholipids increased in colorectal cancer and in UC-associated colorectal cancer. In particular, LPI may have contributed significantly to colitis-associated carcinogenesis.

The gel immersion method and an endoscope with an attached balloon and a cylindrical hood facilitate hemostasis of post-papillectomy bleeding.

Yuki and colleagues report a case of successful endoscopic hemostasis of post-papillectomy bleeding with the gel immersion method and an endoscope with an attached balloon and a cylindrical hood. The visual field was improved with gel and maneuverability was improved using the cylindrical hood and the semi-inflating balloon.

Intervention Strategies to Reduce Surgical Site Infection Rates in Patients Undergoing Rectal Cancer Surgery.

BACKGROUND/AIM: This study aimed to determine the effectiveness of surgical site infection (SSI) prevention approaches in rectal cancer surgery. PATIENTS AND METHODS: A total of 1,408 patients who underwent elective rectal cancer surgery between 1995 and 2017 were reviewed. Patients were divided into three groups: control group (group A, n=245), SSI prevention intervention group (group B, n=516), and laparoscopic or robotic surgery group (group C, n=647). The groups were compared in terms of SSI and anastomotic leakage (AL) incidences, and risk factors for SSI were investigated. RESULTS: The overall SSI and AL rates were 19.4% and 3.6%, respectively. These rates were significantly lower in Group C (9.3%, 1.7%), compared to Groups A (40.0%, 6.1%) and B (22.5%, 3.5%). Abdominoperineal resection, open surgery, operation time, intraoperative bleeding, lack of absorbable sutures, lack of mechanical bowel preparation, and lack of oral antibiotics were independently associated with SSI. CONCLUSION: SSI reduction after rectal cancer surgery was achieved through various intervention strategies.

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.

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.

Risk factors for non-reaching of ileal pouch to the anus in laparoscopic restorative proctocolectomy with handsewn anastomosis for ulcerative colitis.

BACKGROUND/AIMS: Restorative proctocolectomy (RPC) with ileal pouch-anal anastomosis and handsewn anastomosis for ulcerative colitis requires pulling down of the ileal pouch into the pelvis, which can be technically challenging. We examined risk factors for the pouch not reaching the anus. METHODS: Clinical records of 62 consecutive patients who were scheduled to undergo RPC with handsewn anastomosis at the University of Tokyo Hospital during 1989-2019 were reviewed. Risk factors for non-reaching were analyzed in patients in whom hand sewing was abandoned for stapled anastomosis because of nonreaching. Risk factors for non-reaching in laparoscopic RPC were separately analyzed. Anatomical indicators obtained from presurgical computed tomography (CT) were also evaluated. RESULTS: Thirty-seven of 62 cases underwent laparoscopic procedures. In 6 cases (9.7%), handsewn anastomosis was changed to stapled anastomosis because of non-reaching. Male sex and a laparoscopic approach were independent risk factors of non-reaching. Distance between the terminal of the superior mesenteric artery (SMA) ileal branch and the anus > 11 cm was a risk factor for non-reaching. CONCLUSIONS: Laparoscopic RPC with handsewn anastomosis may limit extension and induction of the ileal pouch into the anus. Preoperative CT measurement from the terminal SMA to the anus may be useful for predicting non-reaching.

Risk of extracolonic malignancies and metachronous rectal cancer after colectomy and ileorectal anastomosis in familial adenomatous polyposis.

BACKGROUND: Analysis of long-term clinical outcomes of patients with familial adenomatous polyposis is critical in reducing or preventing the incidence of extracolonic malignancies after initial surgery. The aim of the present study was to clarify the long-term outcomes, and establish a surveillance strategy for surgically treated familial adenomatous polyposis patients. METHODS: Between January 1967 and March 2020, retrospective data were collected from 37 patients with familial adenomatous polyposis treated or monitored in our department. Occurrence of metachronous cancers, including rectal cancers and extracolonic malignancies, and other diseases was analyzed. RESULTS: The median follow-up duration after the first surgery was 13.8 years. Initially, 16 patients underwent total proctocolectomy with ileal pouch-anal anastomosis, 18 underwent total colectomy with ileorectal anastomosis, and three underwent other procedures. A secondary proctectomy was performed for 9 of the 18 patients who underwent ileorectal anastomosis. Rectal cancer was diagnosed in 6 patients who underwent ileorectal anastomosis. In addition, 5 gastric cancer, 2 duodenal cancer, 1 gallbladder cancer, and 1 thyroid cancer cases were diagnosed. The age at which the extracolonic malignancies were diagnosed was >50 years. 4 patients died due to metachronous rectal cancer, gastric cancer, or gallbladder cancer. CONCLUSION: Careful consideration should be paid before choosing ileorectal anastomosis as the treatment procedure for familial adenomatous polyposis patients because completion proctectomy was eventually necessary for half of the patients. Long-term surveillance, with more frequent gastric surveillance for patients over 50 years, is important for the prevention and treatment of extracolonic malignancies in familial adenomatous polyposis patients.

Electric and Manual Oral Hygiene Routines Affect Plaque Index Score Differently.

This cross-sectional study aimed to examine the oral hygiene behaviors in the general population and identify factors affecting oral hygiene behaviors and plaque removal efficacy. A survey was distributed to patients through 11 dental practices in Japan, and each patient's plaque index score (PIS) was recorded. In total, 1184 patients participated (521 women and 660 men), with 84.04% using manual toothbrushes (MTBs) and 15.96% using electric toothbrushes (ETBs). ETB users had a significantly lower PIS compared to MTB users (p = 0.0017). In addition, a statistically significant difference in the PIS was detected in relation to the frequency of brushing per day (≥2 times) and time spent on brushing (≥1 min). Some MTB users spent less than 1 min brushing, while all ETB users spent at least 1 min brushing, and extended brushing periods significantly improved the PIS for the MTB users. MTB users tend to replace brush heads more frequently than ETB users, and the frequency of replacement affected the PIS significantly (p < 0.01) for the MTB users. The status of dental treatment (first visit, in treatment versus recall) also significantly affected the PIS (p < 0.01). The ETB was more effective than the MTB in terms of better plaque removal and reduced frequency of brush head replacement.

Impact of Inferior Mesenteric Artery Occlusion on the Calibre of Collateral Arteries of the Colon.

BACKGROUND/AIM: The inferior mesenteric arteries (IMA) are occluded in some colorectal cancer patients. This study evaluated the impact of IMA occlusion on the calibre of collateral arteries. PATIENTS AND METHODS: As an IMA obstruction model, 20 patients who underwent abdominal aortic aneurysm surgery, with ligated, excluded, or embolised IMA, were enrolled. Changes in the calibre of the left colic arteries (LCAs) and marginal arteries after surgeries were evaluated. RESULTS: The cross-sectional area of the LCA significantly increased after surgery (4.34 mm2 vs. 6.34 mm2, p=0.0009) and that of the marginal artery did not change significantly (2.69 mm2 vs. 3.01 mm2, p=0.33). CONCLUSION: The calibre of the LCA increased after IMA occlusion. The descending branch of the LCA should be confirmed preoperatively to preserve blood flow during a low tie procedure.

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.

Analysis of the Positional Relationship Among the Operator, Camera, and Monitor: Overcoming the Difficulties of Mirror-image Conditions During Laparoscopic Surgery.

BACKGROUND: Although methods to overcome difficulties associated with mirror-image conditions have been investigated, the ideal spatial relationship among the operator line of sight, monitor location, and camera location remains unclear. Moreover, the best training method for improving laparoscopic surgical skills under varying operator line of sight, camera, and monitor positions is unknown. We aimed to investigate the role of laparoscopic training under mirror-image conditions in improving surgical efficiency and whether prior surgical experience affects such training. METHODS: This prospective study was conducted at the Department of Surgical Oncology, Tokyo University, Japan. Twenty-five surgeons participated. Novice (n=14), trained (n=7), and expert (n=4) participants performed the simulated task in a box trainer while varying the positional relationships among the surgeons, camera, and monitor. Five patterns were repeatedly performed 5 times per day for 4 days over 2 weeks. RESULTS: The most significant differences in terms of the time required to complete the task under mirror-image conditions among the 3 groups were on day 1 (novices: 185.8 s, trained: 79.7 s, and experts: 46.5 s, P=0.009). However, after 4 days of training, the corresponding times did not differ among the 3 groups (26.0, 30.7, and 23.1 s, respectively; P=0.415). Laparoscopic training was sufficiently effective under mirror-image conditions. CONCLUSIONS: Mirror-image surgical conditions provided the most difficult setting, because surgeons and assistants often became disoriented, and task performance was most degraded. However, just 4 days of training was found to be sufficient to overcome the difficulties encountered while performing laparoscopic procedures under mirror-image conditions.

Extended Left Colectomy with Coloanal Anastomosis by Indocyanine Green-guided Deloyers Procedure: A Case Report.

The Deloyers procedure is performed after extended left colectomy, enabling the reach of the proximal colon to the rectum for anastomosis while preserving sufficient blood supply. We report a case of the Deloyers procedure performed safely under indocyanine green (ICG) fluorescence guidance. A 50-year-old man with obesity (body mass index, 35.7 kg/m2) and a history of diabetes underwent an extended left hemicolectomy and ultralow anterior resection of the rectum as radical resection for transverse and sigmoid colon cancers and a lower rectal neuroendocrine tumor. Reconstruction was performed by the Deloyers procedure. A necessary length of the transverse colon with reduced blood flow was additionally resected under ICG fluorescence guidance, and a transanal hand-sewn coloanal anastomosis was performed. This is the first report in which the Deloyers procedure was performed successfully with the ICG fluorescence method. ICG fluorescence may be useful when combined with the Deloyers procedure.

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.

Expression of Lysophosphatidylinositol Signaling-relevant Molecules in Colorectal Cancer.

BACKGROUND/AIM: Lysophosphatidylinositol (LPI) is a subspecies of the lysophospholipid mediators produced when phospholipase hydrolyzes membrane phosphatidylinositol. Previously, we used mass spectrometry-based lipidomics to demonstrate that LPI is selectively elevated in colorectal cancer (CRC) tissues. Here, we hypothesized that the expression levels of the LPI biosynthetic enzyme and LPI receptor - DDHD domain containing 1 (DDHD1) and G protein-coupled receptor 55 (GPR55), respectively - may be correlated with malignant potential, and we evaluated their roles in the context of CRC. MATERIALS AND METHODS: Colorectal specimens from 92 CRC patients underwent DDHD1 and GPR55 immunolabeling. Correlation between protein expression levels and clinicopathological variables was examined. RESULTS: Depth of tumor invasion was positively correlated with DDHD1 expression. Regardless of the degree of invasion depth, GPR55 was highly expressed in CRC tissues. Neither DDHD1 nor GPR55 expression levels were associated with disease-free survival. CONCLUSION: DDHD1 expression is associated with depth of tumor invasion in CRC tissues and may be involved in tumor progression.

Rectal neuroendocrine tumor with extracapsular lymph node metastasis: a case report.

The presence of extramural tumor deposits without lymph node structure (EX) is an important prognostic factor in patients with colorectal carcinoma. However, there is no English literature on neuroendocrine tumor (NET) with EX. We report a patient with rectal NET with extracapsular metastasis of a regional lymph node that was considered to be EX. A 51-year-old Japanese woman with diabetes was referred to our hospital for further examination of a submucosal tumor in the lower rectum. She was diagnosed as having rectal NET by immunohistochemical analysis of a biopsy, and underwent laparoscopic low anterior resection with lymph node dissection and covering ileostomy. Pathological findings of the resected specimen showed that the primary tumor was NET-G1 without any lymphatic or venous invasion. A single metastatic deposit was found near the capsule of a NET-negative regional lymph node. She has been free from recurrence for nine months without adjuvant treatments. Extracapsular metastasis of NET on a dissected lymph node in our case was considered to correspond to EX as defined for colorectal carcinoma. This rare case suggests that NET can disseminate to form EX in a similar manner to colorectal carcinoma.

Establishing a novel method for assessing elasticity of internal anal sphincter using ultrasonic real-time tissue elastography.

BACKGROUND: Evaluating anorectal function using real-time tissue elastography (RTE) has not been reported. A previous study reported that in the internal anal sphincter (IAS) of surgical specimens of patients with rectal cancer who underwent abdominoperineal resection, there was an increased fibrosis trend in those who underwent pre-operative chemoradiotherapy (CRT) compared with non-CRT. We speculated that CRT might have induced sclerosis of the IAS because of fibrosis. Therefore, we aimed to establish a method of quantitating the degree of IAS hardness using RTE on endoanal ultrasonography. METHODS: RTE was performed with freehand manual compression under a defined pressure at the middle anal canal. Using the most compressive point in the strain graph, we traced the region of interest in the IAS. The strain histogram showed a frequency distribution of colours according to the degree of strain (numeric scan ranging from 0 to 255; smaller number indicated harder tissue). We defined the mean of the strain histogram as 'elasticity'. Ten patients with locally advanced rectal cancer who underwent pre-operative CRT were prospectively enrolled. We statistically evaluated the correlation between IAS elasticity and maximum resting pressure (MRP) values both at pre- and post-CRT. MRP was examined concurrently with the examination of IAS elasticity. RESULTS: Representativity of elasticity measurements was demonstrated. It revealed a trend: IAS elasticity had a moderate inverse correlation with MRP (r = 0.41, P = 0.07), regardless of whether measurements were made before or after CRT. CONCLUSION: We established a completely novel method for the assessment of elasticity of the IAS, using RTE on endoanal ultrasonography.