Drainage pattern of the splenic flexure vein and its accompanying arteries using three-dimensional computed tomography angiography: a single-centre study of 600 patients.

AIM: The splenic flexure has variable vascular anatomy, and the details of the venous forms are not known. In this study, we report the flow pattern of the splenic flexure vein (SFV) and the positional relationship between the SFV and arteries such as the accessory middle colic artery (AMCA). METHODS: This was a single-centre study using preoperative enhanced CT colonography images of 600 colorectal surgery patients. CT images were reconstructed into 3D angiography. SFV was defined as a vein flowing centrally from the marginal vein of the splenic flexure visible on CT. AMCA was defined as the artery feeding the left side of the transverse colon, separate from the left branch of the middle colic artery. RESULTS: The SFV returned to the inferior mesenteric vein (IMV) in 494 cases (82.3%), the superior mesenteric vein in 51 cases (8.5%) and the splenic vein in seven cases (1.2%). The AMCA was present in 244 cases (40.7%). The AMCA branched from the superior mesenteric artery or its branches in 227 cases (93.0% of cases with existing AMCA). In the 552 cases in which the SFV returned to the IMV, superior mesenteric vein or splenic vein, the left colic artery was the most frequent artery accompanying the SFV (42.2%), followed by the AMCA (38.1%) and the left branch of the middle colic artery (14.3%). CONCLUSIONS: The most common flow pattern of the vein in the splenic flexure is from the SFV to IMV. The SFV is frequently accompanied by the left colic artery or AMCA.

Cadaveric and CT angiography study of vessels around the transverse colon mesentery.

BACKGROUND: Laparoscopic and robotic surgery for transverse colon cancer are difficult due to complex fusion of the foregut and midgut and variation of the vessels of the transverse colon. Although the vessels of the right colon have been investigated, middle colic artery (MCA) variation and the relationship with vessels around the transvers colon are unknown. We investigated variation of the MCA using computed tomography angiography (CTA) and cadaver specimen and the relationship between the superior mesenteric vein (SMV) and MCA using CTA. The classification of vessels around the transverse colon may lead to safer and reliable surgery. METHODS: This study included 505 consecutive patients who underwent CTA in our institution from 2014 to 2020 and 44 cadaver specimens. Vascular anatomical classifications and relationships were analyzed using CT images. RESULTS: The MCA was defined as the arteries arising from the superior mesenteric artery (SMA) that flowed into the transverse colon at the distal ends. The classifications were as follows: type I, branching right and left from common trunk; type II, the right and left branches bifurcated separately from the SMA; and type III, the MCA branched from a vessel other than the SMA. Type II was subclassified into two subtypes, type IIa with one left branch and type IIb with two or more left branches from SMA. In the CTA and cadaver studies, respectively, the classifications were as follows: type I, n = 290 and n = 31; type IIa, n = 211 and n = 13; type IIb, n = 3 and n = 0; and type III, n = 1 and n = 0. We classified the relationship between the MCA and left side of the SMV into three types: type A, a common trunk runs along the left edge of the SMV (n = 173; 59.7%); type B, a right branch of the MCA runs along the left edge of the SMV (n = 116; 40.0%); and type C, the MCA runs dorsal of the SMV (n = 1; 0.3%). CONCLUSIONS: This study revealed that The MCA branching classifications and relationship between the SMV and MCA. Preoperative CT angiography may be able to reliably identify vessel variation, which may be useful in clinical practice.

[A case of retrograde intussusception due to transverse colon cancer detected by abdominal ultrasonography].

A 78-year-old female patient presented to our hospital with abdominal pain and melena. Abdominal ultrasonography detected a multiple concentric ring sign and retrograde invagination mass near the hepatic flexure. Colonoscopy revealed a 40-mm diameter type 1 tumor in the transverse colon near the splenic flexure, and the biopsy specimen demonstrated a well-differentiated adenocarcinoma. Retrograde intussusception due to transverse colon cancer was diagnosed, and laparoscopic transverse colon resection with lymph node dissection was performed. The resected specimen revealed a 48×40mm diameter type 1 tumor in the transverse colon and was diagnosed as pT2N0M0 pStage I. Contrast-enhanced computed tomography was unavailable, but real-time assessment of the invaginated mass and bowel blood flow was possible by abdominal ultrasonography, which was useful in determining the diagnosis and treatment strategy.

Lymph Node Mapping in Transverse Colon Cancer Treated Using Laparoscopic Colectomy With D3 Lymph Node Dissection.

BACKGROUND: Laparoscopic surgery for transverse colon cancer has been excluded from 7 randomized trials for various reasons. The optimal procedure for transverse colon cancer remains controversial. OBJECTIVE: This study aimed to analyze the patterns of lymph node metastasis in transverse colon cancer and to report short- and long-term outcomes of the treatment procedures. DESIGN: This was a single-center retrospective study. SETTINGS: This study was conducted at Cancer Institute Hospital, Tokyo, Japan. PATIENTS: We enrolled 252 patients who underwent laparoscopic surgery for transverse colon cancer. INTERVENTIONS: The transverse colon was divided into 3 segments, and the procedures for transverse colon cancer were based on these segments, as follows: right hemicolectomy, transverse colectomy, and left hemicolectomy. MAIN OUTCOME MEASURES: Postoperatively, the surgeons identified and mapped the lymph nodes from specimens and performed formalin fixation separately to compare the results of the pathological findings. RESULTS: For right-sided, middle-segment, and left-sided transverse colon cancers, the frequency of lymph node metastases was 28.2%, 19.2%, and 19.2%. Skipped lymph node metastasis occurred in right-sided and left-sided transverse colon cancers but not in middle-segment transverse colon cancers. The pathological vascular invasion rate was significantly higher in right and left hemicolectomy than in transverse colectomy. For right hemicolectomy, transverse colectomy, and left hemicolectomy, 5-year overall survival rates were 96.3%, 92.7%, and 93.7%, and relapse-free survival rates were 92.4%, 88.3%, and 95.5%. In multivariate analysis, the independent risk factor for relapse-free survival was lymph node metastasis. LIMITATIONS: Selection bias and different backgrounds may have influenced surgical and long-term outcomes. CONCLUSION: Laparoscopic surgery for transverse colon cancer may be a feasible technique. Harvested lymph node mapping after laparoscopic resection based on D3 lymphadenectomy may help guide the field of dissection when managing patients who have transverse colon cancer. The only independent prognostic factor for relapse-free survival was node-positive cancer. See Video Abstract at http://links.lww.com/DCR/B706.MAPEO DE GANGLIOS LINFÁTICOS EN CÁNCER DE COLON TRANSVERSO TRATADO MEDIANTE COLECTOMÍA LAPAROSCÓPICA CON LINFADENECTOMÍA D3ANTECEDENTES:La cirugía laparoscópica en casos de cáncer de colon transverso fué excluida de siete estudios randomizados mayores por diversas razones. El procedimiento más idóneo en casos de cáncer de colon transverso, sigue siendo controvertido.OBJETIVO:Analizar los patrones de las metástasis en los ganglios linfáticos en casos de cáncer de colon transverso y reportar los resultados a corto y largo plazo de los diferentes procedimientos para su tratamiento.DISEÑO:Estudio retrospectivo en un solo centro de referencia.AJUSTE:Estudio llevado a cabo en el Hospital del Instituto del Cancer, Tokio, Japón.PACIENTES:Fueron incluidos 252 pacientes, sometidos a cirugía laparoscópica por cáncer de colon transverso.INTERVENCIONES:El colon transverso fué dividido en tres segmentos y los procedimientos en casos de cáncer se basaron sobre estos segmentos del tranverso, de la siguiente manera: hemicolectomía derecha, colectomía transversa y hemicolectomía izquierda.PRINCIPALES MEDIDAS DE RESULTADO:En el postoperatorio, los cirujanos identificaron y mapearon los ganglios linfáticos de las piezas quirúrgicas y las fijaron con formaldehido por separado para así poder comparar los resultados con los hallazgos histopatológicos.RESULTADOS:En los cánceres de colon transverso del segmento derecho, del segmento medio y del segmento izquierdo, la frecuencia de metástasis en los ganglios linfáticos fue del 28,2%, 19,2% y 19,2%, respectivamente. Las metástasis en los ganglios linfáticos omitidos se produjo en los cánceres de colon transverso del lado derecho y del lado izquierdo, pero no en los cánceres de colon transverso del segmento medio. La tasa de invasión vascular patológica fue significativamente mayor en la hemicolectomía derecha e izquierda que en la colectomía transversa. Para la hemicolectomía derecha, colectomía transversa y hemicolectomía izquierda, las tasas de supervivencia general a cinco años fueron del 96,3%, 92,7% y 93,7%, y las tasas de supervivencia sin recaída fueron del 92,4%, 88,3% y 95,5%, respectivamente. En el análisis multivariado, el factor de riesgo independiente para la sobrevida sin recidiva fue la metástasis en los ganglios linfáticos.LIMITACIONES:El sesgo de selección y los diferentes antecedentes pueden haber influido en los resultados quirúrgicos a largo plazo.CONCLUSIONES:La cirugía laparoscópica en casos de cáncer de colon transverso puede ser una técnica factible. El mapeo de los ganglios linfáticos recolectados después de la resección laparoscópica basada en la linfadenectomía D3 puede ayudar a guiar el campo de la disección en el manejo de pacientes con cáncer de colon transverso. El único factor pronóstico independiente para el SLR fue el cáncer con ganglios positivos. Consulte Video Resumen en http://links.lww.com/DCR/B706. (Traducción-Dr. Xavier Delgadillo).

Re-interpreting mesenteric vascular anatomy on 3D virtual and/or physical models, part II: anatomy of relevance to surgeons operating splenic flexure cancer.

BACKGROUND: The splenic flexure is irrigated from two vascular areas, both from the middle colic and the left colic artery. The challenge for the surgeon is to connect these two vascular areas in an oncological safe procedure. MATERIALS AND METHODS: The vascular anatomy, manually 3D reconstructed from 32 preoperative high-resolution CT datasets using Osirix MD, Mimics Medical and 3-matic Medical Datasets, were exported as STL-files, video clips, stills and supplemented with 3D printed models. RESULTS: Our first major finding was the difference in level between the middle colic and the inferior mesenteric artery origins. We have named this relationship a mesenteric inter-arterial stair. The middle colic artery origin could be found cranial (median 3.38 cm) or caudal (median 0.58 cm) to the inferior mesenteric artery. The lateral distance between the two origins was 2.63 cm (median), and the straight distance 4.23 cm (median). The second finding was the different trajectories and confluence pattern of the inferior mesenteric vein. This vein ended in the superior mesenteric/jejunal vein (21 patients) or in the splenic vein (11 patients). The inferior mesenteric vein confluence could be infrapancreatic (17 patients), infrapancreatic with retropancreatic arch (7 patients) or retropancreatic (8 patients). Lastly, the accessory middle colic artery was present in ten patients presenting another pathway for lymphatic dissemination. CONCLUSION: The IMV trajectory when accessible, is the solution to the mesenteric inter-arterial stair. The surgeon could safely follow the IMV to its confluence. When the IMV trajectory is not accessible, the surgeon could follow the caudal border of the pancreas.

Re-interpreting mesenteric vascular anatomy on 3D virtual and/or physical models: positioning the middle colic artery bifurcation and its relevance to surgeons operating colon cancer.

BACKGROUND: The impact of the position of the middle colic artery (MCA) bifurcation and the trajectory of the accessory MCA (aMCA) on adequate lymphadenectomy when operating colon cancer have as of yet not been described and/or analysed in the literature. The aim of this study was to determine the MCA bifurcation position to anatomical landmarks and to assess the trajectory of aMCA. METHODS: The colonic vascular anatomy was manually reconstructed in 3D from high-resolution CT datasets using Osirix MD and 3-matic Medical and analysed. CT datasets were exported as STL files and supplemented with 3D printed models when required. RESULTS: Thirty-two datasets were analysed. The MCA bifurcation was left to the superior mesenteric vein (SMV) in 4 (12.1%), in front of SMV in 17 (53.1%) and right to SMV in 11 (34.4%) models. Median distances from the MCA origin to bifurcation were 3.21 (1.18-15.60) cm. A longer MCA bifurcated over or right to SMV, while a shorter bifurcated left to SMV (r = 0.457, p = 0.009). The main MCA direction was towards right in 19 (59.4%) models. When initial directions included left, the bifurcation occurred left to or anterior to SMV in all models. When the initial directions included right, the bifurcation occurred anterior or right to SMV in all models. The aMCA was found in 10 (31.3%) models, following the inferior mesenteric vein (IMV) in 5 near the lower pancreatic border. The IMV confluence was into SMV in 18 (56.3%), splenic vein in 11 (34.4%) and jejunal vein in 3 (9.4%) models. CONCLUSION: Awareness of the wide range of MCA bifurcation positions reported is crucial for the quality of lymphadenectomy performed. The aMCA occurs in 31.3% models and its trajectory is in proximity to the lower pancreatic border in one half of models, indicating that it needs to be considered when operating splenic flexure cancer.

Anatomical variations of the branches from left colic artery and middle colic artery at splenic flexure.

BACKGROUND: Variations of the vasculature at splenic flexure by left colic artery (LCA) and middle colic artery (MCA) remain ambiguous. OBJECTIVES: This study aim to investigate the anatomical variations of the branches from LCA and MCA at splenic flexure area. METHODS: Using ultra-thin CT images (0.5-mm thickness), we traced LCA and MCA till their merging site with paracolic marginal arteries through maximum intensity projection (MIP) reconstruction and computed tomography angiography (3D-CTA). RESULTS: A total of 229 cases were retrospectively enrolled. LCA ascending branch approached upwards till the distal third of the transverse colon in 37.6%, reached the splenic flexure in 37.6%, and reached the lower descending colon in 23.1%, and absent in 1.7% of the cases. Areas supplied by MCA left branch and aMCA were 33.2%, 44.5% and 22.3% in the proximal, middle and distal third of transverse colon of the cases, respectively. The accessory MCA separately originated from the superior mesenteric artery was found in 17.9% of the cases. Mutual correlation was found that, when the LCA ascending branch supplied the distal transverse colon, MCA left branch tended to feed the proximal transverse colon; when the LCA ascending branch supplied the lower part of descending colon, MCA left branch was more likely to feed the distal third of transverse colon. CONCLUSIONS: Vasculature at splenic flexure by LCA and MCA varied at specific pattern. This study could add more anatomical details for vessel management in surgeries for left-sided colon cancer.

Misplacement of the PEG tube through the transverse colon, an uncommon but possible complication.

Misplacement of the Percutaneous Endoscopic Gastrostomy (PEG) tube through the transverse colon mainly by traction is an uncommon complication probably due to inadvertent puncture of colon during PEG placement, resulting in gastrocolocutaneous fistula. Stool drainage through the stoma is usually the only symptom. We report a 52-year-old male with Wernicke-Korsakoff syndrome and PEG tube placement 7 months earlier and replacement one month ago. Due to stool drainage through the stoma was observed, he was performed a computed tomography (CT) in which PEG tube was visualized lodged in transverse colon without pneumoperitoneum associated. Due to important morbility, endoscopic management was decided. Balloon was removed through cutaneous orifice and Ovesco clip was placed simultaneously, achieving a complete closure of wall defect. Although spontaneous closure of the fistula usually happens, surgery is sometimes required, with endoscopic treatment being a less invasive and effective alternative to solve this complication.

Transverse colonic volvulus due to mesenteric fibromatosis: a case report.

BACKGROUND: Colonic volvulus, a condition in which a colonic segment partially twists around its base, is the third leading cause of large bowel obstruction after colonic neoplasms and diverticular disease. However, volvulus of the transverse colon is the rarest type of large intestinal volvulus. Moreover, the occurrence of transverse colonic volvulus secondary to a benign tumor originating from outside the intestine has never been reported. We hereby report a case of transverse colonic volvulus caused by mesenteric fibromatosis. CASE PRESENTATION: A 53-year-old female with a history of rheumatoid arthritis and thyroid tumor presented with abdominal pain for 1 day. Abdominal computed tomography revealed intestinal torsion at the hepatic flexure. Twisted and obstructed mucosa of the transverse colon was observed during colonoscopy, but no tumor invasion of the mucosal surface was detected. A solid mass of a mesenteric origin with involvement of the transverse colon was observed during surgery. The mass was diagnosed surgically as transverse colonic volvulus induced by a mesenteric tumor. Hence, the patient underwent a right hemicolectomy. Histopathological results indicated mesenteric desmoid-type fibromatosis. The postoperative recovery was uneventful, and the patient was discharged 8 days after surgery. CONCLUSIONS: Although mesenteric fibromatosis is rare, this disease should be considered when managing transverse colonic volvulus resulting from nonmucosal tumors.

Effect of dynamic position changes during colonoscope withdrawal: a meta-analysis of randomized controlled trials.

BACKGROUND: Colonoscopies are considered to be the primary screening test and gold standard test for colorectal cancer. Position changes during colonoscope withdrawal are believed to be associated with an increased adenoma detection rate (ADR) and polyp detection rate (PDR). However, previous results conflicted, and this study aimed to elucidate the effectiveness of dynamic position changes during colonoscope withdrawal. METHODS: The relevant publications were identified by searching the medical databases. The primary outcomes were the ADR and PDR, which were pooled and analyzed. The secondary outcome was the withdrawal time. The studies that supplied the ADR and PDR for different segments of the colon were separated into subgroup analyses. RESULTS: Five randomized controlled trials were eligible for analysis. The total ADR was higher with dynamic position changes than with a static position (odds ratio, [OR] 1.34; 95% confidence interval [CI] 1.13-1.59; p < 0.001), with low evidence of between-study heterogeneity (I2 = 0%). Although the total PDR was slightly higher with dynamic position changes than with a static position (OR 1.23; 95% CI 0.88-1.73), there difference was not statistically significant (p = 0.22). The withdrawal time was only increased by 0.47 min (95% CI - 0.11 to 1.06) with dynamic position changes, without statistical significance (p = 0.11). The subgroup analysis showed that the ADR and PDR for the transverse colon were higher with dynamic position changes, with pooled estimates of ADR (OR 1.72; 95% CI 1.02-2.88; p = 0.04) and PDR (OR 1.79; 95% CI 1.08-2.96; p = 0.02). CONCLUSION: Dynamic position changes during colonoscope withdrawal increased the total ADR; however, no obvious increase was found in the total PDR. The withdrawal time was not significantly prolonged with dynamic position changes. Subgroup analysis showed that the ADR and PDR in the transverse colon were obviously improved with dynamic position changes.

A case of reversed intestinal rotation revealed by volvulus in adult: anatomo-radiological correlations.

We report a case of reversed rotation (RR) of the midgut, the rarest form of intestinal malrotation (IMR), revealed by a chronic volvulus, in a 42-year-old woman presenting with episodes of abdominal pain occurring after heavy meals. The complete preoperative diagnosis was obtained by contrast-enhanced computed tomography (CT). Classical signs of volvulus were associated with typical findings of RR comprising an unusual position of the third duodenum in front of the mesenteric vessels and a very unusual location of the transverse colon behind these vessels. Complete absence of fixation of the right colon allowed secondary volvulus. A detailed reminder of the embryology of IMR and RR is presented.

Vascular anatomy of the splenic flexure, focusing on the accessory middle colic artery and vein.

AIM: Recently, the accessory middle colic artery (AMCA) has been recognized as the vessel that supplies blood to the splenic flexure. However, the positional relationship between the AMCA and inferior mesenteric vein (IMV) has not been evaluated. Herein, we aimed to evaluate the anatomy of the AMCA and the splenic flexure vein (SFV). METHOD: Two hundred and five patients with colorectal cancer who underwent enhanced CT preoperatively were enrolled in the present study. The locations of the AMCA and IMV were evaluated, focusing on the positional relationship between the vessels and pancreas - below the pancreas or to the dorsal side of the pancreas. RESULTS: The AMCA was observed in 74 (36.1%) patients whereas the SFV was found in 177 (86.3%) patients. The left colic artery (LCA) was the major artery accompanying the SFV in 87 (42.4%) of patients. The AMCA accompanied the SFV in 65 (32.7%) patients. In 15 (7.8%) patients, no artery accompanied the SFV. The origin of the AMCA was located on the dorsal side of the pancreas in 15 (20.3%) of these 74 patients. Similarly, the destination of the IMV was located on the dorsal side of the pancreas in 65 (31.7%) of patients. CONCLUSION: The SFV was observed in most patients, and the LCA or AMCA was the common accompanying artery. In some patients these vessels were located on the dorsal side of the pancreas and not below it. Preoperative evaluation of this anatomy may be beneficial for lymph node dissection during left-sided hemicolectomy.

Arterial anatomy of the splenic flexure using preoperative three-dimensional computed tomography.

BACKGROUND: To perform a safe and precise laparoscopic surgery for the splenic flexure cancer, it is important for surgeons to gain a preoperative understanding of the running of the feeding artery of the splenic flexure. We evaluated the blood supply to the splenic flexure by using preoperative three-dimensional computed tomography (3D-CT). METHOD: We retrospectively analyzed a total of 88 patients with colorectal cancer who underwent preoperative 3D-CT at our institutions between April 2016 and June 2017. RESULTS: The arterial blood supply to the splenic flexure was divided into four patterns as follows: type 1, the left branch of the middle colic artery (MCA) with common trunk and the left colic artery (LCA) (n = 48, 54.5%); type 2, the left branch of the MCA with independent origin and the LCA (n = 8, 9.1%); type3, the accessory-MCA (A-MCA) and the LCA (n = 27, 30.7%); and type4, the LCA alone (n = 5, 5.7%). The MCA had the common trunk of the right and left branches in the majority of cases (85.2%). The right and left branches of the MCA arose separately from the superior mesenteric artery (SMA) in 8 of 88 patients (9.1%). CONCLUSIONS: The arterial patterns of the splenic flexure were classified into four patterns by using preoperative 3D-CT. The A-MCA existed in 30% of the patients in this study. These information should be helpful to perform the optimal surgery for the splenic flexure cancer.

Spontaneous regression of transverse colon cancer with high-frequency microsatellite instability: a case report and literature review.

BACKGROUND: Spontaneous regression (SR) of colorectal cancer (CRC) is extremely rare, and only few cases have been reported. Although it is not yet clarified, a plausible mechanism for SR of CRC is an immunological event. CASE PRESENTATION: In this report, we present the case of SR of primary CRC in a 78-year-old man. Preoperative colonoscopy was performed, and a type 2 tumor measuring 30 mm in diameter in the transverse colon was detected. The biopsy revealed a poorly differentiated adenocarcinoma. Colectomy was performed 2 months after initial colonoscopy. During the surgery, only a 10-mm ulcer harboring a polypoid lesion measuring 8.5 mm was detected in the resected tissue; no other masses or carcinoma cells were seen on histological examination. Afterwards, the biopsy specimens were reanalyzed, and immunohistological analysis verified this as adenocarcinoma with stroma-infiltrating lymphocytes. Further analysis revealed a loss of two mismatch repair proteins, suggesting sporadic high-frequency microsatellite instability (MSI-H). CONCLUSION: According to previous literature, a common site of SR in CRC is the proximal colon, which is a feature of MSI-H CRC. However, our report showed a rare case of SR of CRC, which was in the transverse colon, with MSI-H present. This report indicates a relationship between immunological features of MSI-H and the occurrence of SR of CRC. A better understanding of this phenomenon and the mechanisms involved will have significant preventive and therapeutic implications for CRC, including anti-PD-1 immune checkpoint inhibitor therapy.

The one that got away: a rare complication after PEG tube placement.

A 74 year-old male patient was admitted to the emergency department due to diarrhea of a one-month duration. The patient had 5 to 7 bowel movements/day of liquid stool, without blood or mucus. He had also undergone a percutaneous endoscopic gastrostomy (PEG) tube placement 10 weeks previously due to post-stroke dysphagia, with endoscopic confirmation of its correct positioning. A course of antibiotics had already been prescribed and there was no improvement of the symptoms.

Regression of a giant pseudopolyp in a patient with colonic Crohn's disease after therapy with infliximab.

Giant inflammatory pseudopolyps (> 15 mm) are an uncommon complication of inflammatory bowel disease (IBD) and a differential diagnosis with adenomas and carcinomas is challenging. Although usually asymptomatic, they may result in intestinal obstruction or intussusception due to their size. The standard management involves lesion biopsies and endoscopic excision for selected cases; surgery is usually reserved for size-associated complications or an uncertain pathology. We report the case of a 43-year-old female patient with Crohn's disease (CD) in clinical remission, with no specific treatment at the time. A giant pseudopolyp of 40-mm was found during a screening colonoscopy. Therapy was initiated with infliximab and azathioprine in an attempt to reduce the size of the polyp and allow an endoscopic resection. Additional colonoscopies were performed following induction doses at weeks 0, 2, and 6, which revealed a reduced lesion size. Mucosal resection was attempted but failed due to severe fibrosis, which prevented base injections from lifting up the polyp. However, a follow-up colonoscopy three months later showed that the lesion had completely disappeared. The evidence in the literature regarding giant pseudopolyp management is scarce, but reports indicate that they rarely disappear with medical therapy alone and usually require surgery or endoscopic resection.

Analysis of the Vascular Interrelationships Among the First Jejunal Vein, the Superior Mesenteric Artery, and the Middle Colic Artery.

BACKGROUND: The technical difficulty of laparoscopic surgery for transverse colon cancer is partly due to the vascular variability around the middle colic vessels. Although individual variations in the arteries or veins in this area were previously investigated, the vascular interrelationships between these vessels remain unknown. This study was designed to investigate the vascular interrelationships between the arteries and veins around the middle colic vessels and to provide practically useful classifications. METHODS: This study included 105 consecutive patients who underwent colorectal surgery for colorectal tumors in our institution in 2016. Patients with a history of colectomy were excluded. Vascular anatomical classifications were analyzed by evaluating thin-slice images of preoperative contrast-enhanced computed tomography. RESULTS: Vascular anatomical patterns were classified according to whether the first jejunal vein ran behind (type A) or in front (type B) of the superior mesenteric artery. Type B was subclassified into two subtypes, depending on whether the middle colic artery originated cephalad (type B1) or caudad (type B2) to the first jejunal vein. We identified 83 (79.0%) cases of type A, 11 (10.5%) of type B1, and 11 (10.5%) of type B2. In 17 cases, the middle colic vein drained into the inferior mesenteric vein, and all of these were type A (P = 0.0202). Furthermore, in eight cases, the middle colic vein drained into the first jejunal vein, and all of these were type B (P < 0.0001). CONCLUSIONS: This study elucidated the vascular interrelationships around the middle colic vessels. Our findings provided important knowledge for laparoscopic surgery in treating transverse colon cancer.

Linked color imaging reduces the miss rate of neoplastic lesions in the right colon: a randomized tandem colonoscopy study.

BACKGROUND: Linked color imaging (LCI) is a newly developed image-enhancing endoscopy technology that provides bright endoscopic images and increases color contrast. We investigated whether LCI improves the detection of neoplastic lesions in the right colon when compared with high definition white-light imaging (WLI). METHODS: Consecutive patients undergoing colonoscopy were randomized (1:1) after cecal intubation into right colon inspection at first pass by LCI or by WLI. At the hepatic flexure, the scope was reintroduced to the cecum under LCI and a second right colon inspection was performed under WLI in previously LCI-scoped patients (LCI-WLI group) and vice versa (WLI-LCI group). Lesions detected on first- and second-pass examinations were used to calculate detection and miss rates, respectively. The primary outcome was the right colon adenoma miss rate. RESULTS: Of the 600 patients enrolled, 142 had at least one adenoma in the right colon, with similar right colon adenoma detection rates (r-ADR) in the two groups (22.7 % in LCI-WLI and 24.7 % in WLI-LCI). At per-polyp analysis, double inspection of the right colon in the LCI-WLI and WLI-LCI groups resulted in an 11.8 % and 30.6 % adenoma miss rate, respectively (P < 0.001). No significant difference in miss rate was found for advanced adenomas or sessile serrated lesions. At per-patient analysis, at least one adenoma was identified in the second pass only (incremental ADR) in 2 of 300 patients (0.7 %) in the LCI - WLI group and in 13 of 300 patients (4.3 %) in the WLI - LCI group (P = 0.01). CONCLUSIONS: LCI could reduce the miss rate of neoplastic lesions in the right colon.