Accessory Middle Colic Artery Research Articles

Surgical anatomy of the dorsal pancreatic artery: Considering embryonic development

ObjectivesThe dorsal pancreatic artery (DPA) is a pancreatic branch with various anatomical variations. Previous studies mostly focused on the origin of the DPA, and its pathways and branching patterns have rarely been examined. The purpose of this study was to investigate the branching patterns and pathways of the DPA. MethodsThis study included 110 patients who underwent computed tomography scans. We examined the pathways and branching patterns of the DPA. ResultsThe DPA was identified in 101 patients (92%), and originated from the splenic artery in 30 patients (31%), the common hepatic artery in 17 patients (17%), the celiac trunk in 10 patients (10%), the superior mesenteric artery in 27 patients (27%), the replaced right hepatic artery in 7 patients (7%), the inferior pancreaticoduodenal artery in 5 patients (5%), and other arteries in 3 patients (3%). Four distinct types of branches were identified as follows: the superior branch (32%), the inferior branch (86%), the right branch (80%), and the accessory middle colic artery (12%). Additionally, the arcs of Buhler and Riolan were observed in two patients each and their anastomotic vessels followed almost the same pathway as the DPA. ConclusionA number of variations of the DPA were observed with regard to its origin and branching pattern; however, the DPA and its branches always ran along the same pathway, as summarized in Fig. 4. The anatomical information gained from this study may contribute to performing safe pancreatic resections.

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

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). 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. 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%). 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.

Verification of blood flow path reconstruction mechanism in distal sigmoid colon and rectal cancer after high IMA ligation through preoperative and postoperative comparison by manual subtraction CTA

IntroductionWe aimed to investigate manual subtraction computed tomography angiography (MS-CTA) to further confirm the distribution and classification of LCA (left colic artery) ascending/descending branches, then observe the postoperative blood flow path to illustrate how the above branches evolved to postoperative blood path. Material and methods89 patients with distal sigmoid and rectal cancer were referred in our observation and underwent MS-CTA between June 2020 and March 2022. We classified the distribution of LCA and confirmed whether there exists AMCA (accessory middle colic artery). Then we planned blood flow path based on the classification of LCA branches before operation. High ligation was applied in regular radical surgery. During operation, we carefully protect the bifurcation of ascending and descending LCA. Then we compared the planned blood flow path with the actual postoperative blood flow path to verify the mechanism we proposed previously. ResultsOf 89 patients, 82 cases met our criteria, we summarized 6 distribution pattens of LCA ascending and descending branches. These preoperative pattens are consistent with the inspection during operation. The postoperative blood flow path of 6 pattens is evolved from the above adjacent anastomotic branches and is consistent with the planned blood flow path. We also found 2 cases with IMA stenosis and 1 case with SMA stenosis under pathological condition, and their compensatory blood flow path is in accordance with our theory. The rate of the anastomotic leakage in our study group is relatively low (7.3%). ConclusionMS-CTA could confirm the distribution of LCA and AMCA, display accurate postoperative blood reconstruction path after IMA high ligation, and it further verified the mechanism we proposed previously, which is the proximal anastomotic branches forming new blood flow path from high-pressure area to the low-pressure area. This mechanism might be helpful for performing accurate laparoscopic sigmoid and rectal cancer surgery.

A multicenter cohort study on mapping of lymph node metastasis for splenic flexural colon cancer.

There have been no reports of searching for metastases to lymph nodes along the accessory middle colic artery (aMCA). The aim of this study was to investigate the metastasis rate of the aMCA for splenic flexural colon cancer. Patients with histologically proven colon carcinoma located in the splenic flexure, clinically diagnosed as stage I-III were eligible for this study. Patients were retrospectively and prospectively enrolled. The primary endpoint was frequency of lymph node metastasis to the aMCA (station 222-acc and 223-acc). The secondary endpoint was the frequency of lymph node metastasis to the middle colic artery (MCA) (station 222-lt and 223) and left colic artery (LCA) (station 232 and 253). Between January 2013 and February 2021, a total of 153 consecutive patients were enrolled. The location of the tumor was 58% in the transverse colon and 42% in the descending colon. Lymph node metastases were observed in 49 cases (32%). The presence of aMCA rate was 41.8% (64 cases). The metastasis rates of stations 221, 222-lt, and 223 were 20.0%, 1.6%, and 0%, and stations 231, 232, and 253 were 21.4%, 1.0%, and 0%, respectively. The metastasis rates of stations 222-acc and 223-acc were 6.3% (95% confidence interval: 1.7%-15.2%) and 3.7% (95% confidence interval: 0.1%-19%), respectively. This study identified the distribution of lymph node metastases from splenic flexural colon cancer. If the aMCA is present, this vessel should be targeted for dissection, taking into account the frequency of lymph node metastasis.

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

BackgroundThe 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 methodsThe 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.ResultsOur 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.ConclusionThe 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.Graphical abstract

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

Variations of the vasculature at splenic flexure by left colic artery (LCA) and middle colic artery (MCA) remain ambiguous. This study aim to investigate the anatomical variations of the branches from LCAand MCA at splenic flexure area. 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). 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 reachedthe 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. 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.

Laparoscopic low anterior resection for rectal cancer wherein the inferior mesenteric artery arose from the superior mesenteric artery: a case report

BackgroundFew cases have been reported of colorectal cancer with inferior mesenteric artery (IMA) branching abnormalities; therefore, the lymphatic flow in such cases remains unknown. We report the first case of locally advanced rectal cancer in which the IMA arose from the superior mesenteric artery (SMA) in which we achieved to visualize the lymphatic flow.Case presentationA 65-year-old woman complaining of bloody stools was investigated in our hospital and suspected with rectal cancer. Colonoscopy and abdominal enhanced computed tomography (CT) revealed a circumscribed, localized ulcerative tumor in the rectum. 3-Dimensional contrast-enhanced computed tomography (3D-CT) showed that the IMA arose from the SMA. The patient was diagnosed with rectal cancer (cT3N0M0, cStage IIa) and laparoscopic low anterior resection was performed. The sigmoid colon was resected using the medial approach. Only the plexus of the colic branch of the lumbar splanchnic nerve was observed at the site where the root of the IMA usually exists and showed interruption of the indocyanine green (ICG) fluorescence-illuminated lymphatics. The root of the IMA was ligated, and Japanese D3 lymphadenectomy was performed, preserving the accessory middle colic artery. All fluorescent lymph nodes were resected. The pathological diagnosis was pT4aN1aM0 stage IIIb. The patient’s postoperative course was uneventful. Adjuvant chemotherapy was administered, and the patient was recurrence-free at 1.5 years after surgery.ConclusionsWe were able to perform safe and appropriate surgery oncologically, despite abnormal vascular anatomy, due to preoperative identification using 3D-CT and intraoperative navigation using ICG administration.

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.

Surgical anatomy of the accessory middle colic artery: a meta-analysis with implications for splenic flexure cancer surgery.

Surgical resection of splenic flexure cancers (SFCs) is technically demanding due to the complex regional anatomy, characterized by the presence of embryological adhesions, close proximity to the pancreas and spleen, and a highly heterogeneous arterial supply and lymphatic drainage. The accessory middle colic artery (AMCA) is increasingly being recognized as an important source of blood supply to the splenic flexure. The aim of this study is to determine the prevalence and anatomical features of the AMCA. A systematic search of the scientific literature was conducted on PubMed and Embase from inception to November 2020 to identify potentially eligible studies. Data were extracted and prevalence was pooled into a meta-analysis using MetaXL and Meta-Analyst software. A total of 16 studies (n=2203 patients) were included. The pooled prevalence (PP) of the AMCA was 25.4% (95% CI 18.1-33.4). Its prevalence was higher in patients without a left colic artery (LCA) (PP=83.2%; 95% CI 70.4-93.1). The commonest origin for the AMCA was the superior mesenteric artery (PP=87.9%; 95% CI 86.4-90.7). The AMCA shared a common trunk/gave rise to pancreatic branches in 23.1% of cases (95% CI 15.3-31.9). The AMCA contributes to the vascularization of the splenic flexure in approximately 25% of individuals, and may be an important feeder artery to SFCs, especially in the absence of a LCA. Preoperative identification of this artery is important to ensure optimal surgery for SFC and minimize complications.

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

BackgroundThe impact of the position of the middle colic artery (MCA) bifurcationand the trajectory of the accessory MCA (aMCA) on adequate lymphadenectomy whenoperating colon cancer have as of yet not been described and/or analysed in theliterature. The aim of this study was to determine the MCA bifurcation position toanatomical landmarks and to assess the trajectory of aMCA.MethodsThe colonic vascular anatomy was manually reconstructed in 3D fromhigh-resolution CT datasets using Osirix MD and 3-matic Medical and analysed. CTdatasets were exported as STL files and supplemented with 3D printed models whenrequired.ResultsThirty-two datasets were analysed. The MCA bifurcation was left to thesuperior mesenteric vein (SMV) in 4 (12.1%), in front of SMV in 17 (53.1%) and rightto SMV in 11 (34.4%) models. Median distances from the MCA origin to bifurcation were3.21 (1.18–15.60) cm. A longer MCA bifurcated over or right to SMV, while a shorterbifurcated left to SMV (r = 0.457, p = 0.009). The main MCA direction was towards right in19 (59.4%) models. When initial directions included left, the bifurcation occurredleft 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 foundin 10 (31.3%) models, following the inferior mesenteric vein (IMV) in 5 near thelower pancreatic border. The IMV confluence was into SMV in 18 (56.3%), splenic veinin 11 (34.4%) and jejunal vein in 3 (9.4%) models.ConclusionAwareness of the wide range of MCA bifurcation positions reported iscrucial for the quality of lymphadenectomy performed. The aMCA occurs in 31.3% modelsand its trajectory is in proximity to the lower pancreatic border in one half ofmodels, indicating that it needs to be considered when operating splenic flexurecancer.

Arterial blood supply from accessary middle colic artery to the pancreas

Background: An accessory middle colic artery (AMCA) is an aberrant artery feeding the splenic flexure of the colon. Little is known about the branching pattern of the AMCA to the pancreas. We aimed to evaluate the branching pattern of the AMCA from the superior mesenteric artery (SMA) with special reference to the pancreatic artery using multidetector-row computed tomography (MDCT).

Accessory Middle Colic Artery Arising from the Splenic Artery—A Case Report—

Accessory Middle Colic Artery Arising from the Splenic Artery—A Case Report—

Evaluation of vascular anatomy for colon cancer located in the splenic flexure using the preoperative three-dimensional computed tomography angiography with colonography.

The aim of this study is to reveal the vascular branching variation in SFC(splenic flexure cancer) patients using the preoperative three-dimensional computed tomography angiography with colonography (3D-CTAC). We retrospectively analyzed patients with SFC who underwent preoperative 3D-CTAC between January 2014 and December 2019. Among 1256 colorectal cancer (CRC) patients, 96 (7.6%) manifested SFC. The arterial branching from the superior mesenteric artery (SMA) was classified into five patterns, as follows: (type 1A) the left branch of middle colic artery (LMCA) diverged from middle colic artery (MCA) (N = 47, 49.0%); (2A) the LMCA diverged from the MCA and the accessory middle colic artery (AMCA) (N = 26, 27.1%); (3A) the LMCA independently diverged from the SMA (N = 16, 16.7%); (4A) the LMCA independently diverged from the SMA and AMCA (N = 3, 3.1%); (5A) only the AMCA and the LMCA was absent (N = 4, 4.1%). Venous drainage was classified into four patterns, as follows: (type 1V) the SFV flows into the inferior mesenteric vein (IMV) then back to the splenic vein (N = 50, 52.1%); (2V) the SFV flows into the IMV then back to the superior mesenteric vein (SMV) (N = 19, 19.8%); (type 3V) the SFV independently flows into the splenic vein (N = 3, 3.1%); (type 4V) the SFV is absent (N = 24, 25.0%). 3D-CTAC could reveal accurate preoperative tumor localization and vascular branching. These classifications should be helpful in performing accurate complete mesocolic excision and central vessel ligation for SFC.

Laparoscopic left hemicolectomy with regional lymph node navigation and intracorporeal anastomosis for splenic flexure colon cancer.

Laparoscopic approaches have become a standard strategy for colon cancer patients who undergo surgical treatment. Complete mesocolic excision (CME) with central vascular ligation (CVL) is the fundamental principle of radical resection of colon cancers. Splenic flexure colon cancer (SFCC) is rare, accounting for less than 4% of all colorectal cancer cases. Moreover, a laparoscopic approach for SFCC following the CME/CVL concept can be challenging because the blood supply of the splenic flexure is derived from either the middle colic artery (MCA) branching from the superior mesenteric artery, the left colic artery (LCA) branching from the inferior mesenteric artery. In addition, approximately one third of SFCC patients have an accessory MCA that can originate from the celiac trunk. Herein, we describe the technical procedure of a laparoscopic left hemicolectomy for SFCC using indocyanine green (ICG) for necessary and sufficient lymphadenectomy followed by intracorporeal anastomosis. Two injections of ICG (0.5mg/0.2ml × 2) into the subserosa of the proximal and distal sides of the tumor preceded the surgical procedure after pneumoperitoneum. Near infrared images obtained throughout the laparoscopic procedure helped visualize lymphatic drainage vessels and inform decision making for determining vessels requiring ligation according to the CVL concept: MCA, LCA or accessory MCA. Complete intracorporeal anastomosis following necessary and sufficient lymphadenectomy with ICG can minimize the dissecting area of the laparoscopic left hemicolectomy for SFCC patients. Intravenous ICG injection (2.5mg) after anastomosis helps confirm blood perfusion at the anastomosis site. Four patients with SFCC underwent a laparoscopic colectomy under ICG navigation in 2019 at our institute. The median operative time was 237min, the median estimated blood loss was 0ml, and the median number of dissected lymph nodes was 13. No patients experienced postoperative complications. In conclusion, laparoscopic left hemicolectomy with ICG navigation and intracorporeal anastomosis for SFCC patients may be a feasible option for the radical resection of colon cancer.

A three-dimensional computed tomography angiography study of the anatomy of the accessory middle colic artery and implications for colorectal cancer surgery

PurposeIn the present study, we focused on the accessory middle colic artery and aimed to increase the safety and curative value of colorectal cancer surgery by investigating the artery course and branching patterns.MethodsWe included 143 cases (mean age, 70.4 ± 11.2 years; 86 males) that had undergone surgery for neoplastic large intestinal lesions at the First Department of Surgery at Yamagata University Hospital between August 2015 and July 2018. We constructed three-dimensional (3D) computed tomography (CT) angiograms and fused them with reconstructions of the large intestines. We investigated the prevalence of the accessory middle colic artery, the variability of its origin, and the prevalence and anatomy of the arteries accompanying the inferior mesenteric vein at the same level as the origin of the inferior mesenteric artery.ResultsAccessory middle colic artery was observed in 48.9% (70/143) cases. This arose from the superior mesenteric artery in 47, from the inferior mesenteric artery in 21, and from the celiac artery in two cases. In 78.2% (112/143) cases, an artery accompanying the inferior mesenteric vein was present at the same level as the origin of the inferior mesenteric artery; this artery was the left colic artery in 92, the accessory middle colic artery in 11, and it divided and became the left colic artery and the accessory middle colic artery in 10 cases.Conclusion3D CT angiograms are useful for preoperative evaluation. Accessory middle colic arteries exist and were observed in 14.9% of cases.

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

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). 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. 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. 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.

Preoperative fecal elastase-1 (FE-1) adds value in predicting post-operative pancreatic fistula: not all soft pancreas share the same risk - A prospective analysis on 105 patients.

An accessory middle colic artery (AMCA) is an aberrant artery feeding the splenic flexure of the colon. Little is known about the branching pattern of an AMCA. We aimed to evaluate the branching pattern of the AMCA from the superior mesenteric artery (SMA) with special reference to the pancreatic artery using multidetector-row computed tomography (MDCT) before surgery.We investigated 112 patients who underwent contrast-enhancement MDCT before surgical resection of the pancreas between January 2015 and July 2018. The pancreatic branch from the AMCA was divided into the dorsal pancreatic artery (DPA) and the inferior pancreaticoduodenal artery (IPDA). The branching level and angle of the AMCA from the SMA were also evaluated.The AMCA was present in 27.7% of patients (n = 31/112). The AMCA branching pattern was classified into four types: type A, no branch from the AMCA (n = 20); type B, a common trunk with the DPA (n = 6); type C, a common trunk with the IPDA (n = 3); and type D, a common trunk with the DPA and IPDA (n = 2). The AMCA with the IPDA (types C and D) branched more proximally compared to the AMCA without the IPDA (P = 0.04). The AMCA branched vertically from the SMA in most cases (n = 24/31, 77.4%).The AMCA had a pancreatic branch in 8.9% (10/112) of cases. Special attention should be paid to its branching pattern in pancreatic and colon surgery.

Arterial blood supply to the pancreas from accessary middle colic artery

BackgroundAn accessory middle colic artery (AMCA) is an aberrant artery feeding the splenic flexure of the colon. Little is known about the branching pattern of an AMCA. We aimed to evaluate the branching pattern of the AMCA from the superior mesenteric artery (SMA) with special reference to the pancreatic artery using multidetector-row computed tomography (MDCT) before surgery. MethodsWe investigated 112 patients who underwent contrast-enhancement MDCT before surgical resection of the pancreas between January 2015 and July 2018. The pancreatic branch from the AMCA was divided into the dorsal pancreatic artery (DPA) and the inferior pancreaticoduodenal artery (IPDA). The branching level and angle of the AMCA from the SMA were also evaluated. ResultsThe AMCA was present in 27.7% of patients (n = 31/112). The AMCA branching pattern was classified into four types: type A, no branch from the AMCA (n = 20); type B, a common trunk with the DPA (n = 6); type C, a common trunk with the IPDA (n = 3); and type D, a common trunk with the DPA and IPDA (n = 2). The AMCA with the IPDA (types C and D) branched more proximally compared to the AMCA without the IPDA (P = 0.04). The AMCA branched vertically from the SMA in most cases (n = 24/31, 77.4%). ConclusionsThe AMCA had a pancreatic branch in 8.9% (10/112) of cases. Special attention should be paid to its branching pattern in pancreatic and colon surgery.

Preoperative Evaluation of Blood Vessel Anatomy Using 3-Dimensional Computed Tomography for Laparoscopic Surgery of Transverse Colon Cancer

This study describes the efficacy of the evaluation of blood vessel anatomy by 3-dimensional computed tomography (3D-CT) for laparoscopic surgery for transverse colon cancer (TCC). A total of 102 patients with TCC were examined by preoperative 3D-CT to clarify their blood vessel anatomy at Tokyo Medical University Hospital between January 2010 and December 2015, before undergoing laparoscopic surgery using the obtained 3D-CT data. Regarding blood vessel variation, the middle colic artery (MCA) was present in all patients (100%). The common duct type was observed in 89 patients (87.3%), and a type of branch separate from the superior mesenteric artery was observed in 13 patients (12.7%). The accessory MCA was present in 25 patients (24.5%). The middle colic vein was present in all patients (100%), and it drained into the following vessels: the superior mesenteric vein, gastrocolic trunk, first jejunal vein, and inferior mesenteric vein [67 (65.8%), 25 (24.5%) 8 (7.8%), and 2 (1.9%) patients, respectively]. Regarding the surgical outcome, the bleeding volume was 43 g, the operative time was 218 minutes, the number of harvested lymph nodes was 21, the proximal resection margin was 164 mm, the distal resection margin was 105 mm, and the length of postoperative hospital stay was 10 days. Although complicated variations and anomalies in the MCA and the contiguous veins were observed, preoperative 3D-CT will be useful for surgeons performing laparoscopic surgery on patients with TCC.

Variations in the Vascular Anatomy of the Right Colon and Implications for Right-Sided Colon Surgery.

Knowledge of the normal pattern and variations of the blood supply of the right colon is crucial for better outcomes after colon surgery. The purpose of this study was to describe the precise vascular anatomy of the right colon according to surgical perspective. Adult fresh cadavers were dissected between January 2013 and October 2015, focusing on the venous and arterial anatomy of the right side of the colon. Macroscopic anatomical dissections were performed on 111 adult fresh cadavers with emphasis on the vascular anatomy of the right colon. The colic tributaries of the superior mesenteric artery and vein were documented in writing. Furthermore, the dissections were recorded with a video camera. The incidence of colic arteries arising from the superior mesenteric artery included ileocolic artery, 100%; right colic artery, 33.3%; middle colic artery, 100%; and accessory middle colic artery, 11,7%. All 111 cadavers had a single ileocolic vein, which drained into the superior mesenteric vein in 103 cases (92.8%), into the gastro-pancreatico-colic trunk in 7 cases (6.3%), and into the jejunal trunk in 1 case (0.9%). The drainage site of the ileocolic vein to the superior mesenteric vein varied, and in 9% of cases the ileocolic vein did not accompany the ileocolic artery. The gastro-pancreatico-colic trunk was detected in 87 cases (78.4%); with several forms of the origin of the respective branches, the gastropancreatic trunk was detected in 24 cases (21.6), and the classic gastrocolic trunk of Henle was not detected. Variations were found in the formation and drainage routes of other venous colic tributaries of the superior mesenteric vein. This study is limited by its use of cadavers in that it is impossible to trace each vessel to its origin in live surgery. Surgeons must watch, observe, and bear in mind that vascular variations can occur. Awareness of these complex variations may improve the quality of surgery and may prevent devastating complications during right-sided colon resections.