Cadaveric Study of Colon-Lengthening Maneuvers After Sigmoidectomy.

BACKGROUND: Creation of a tension-free colorectal anastomosis after left colon resection or low anterior resection is a key requirement for technical success. The relative contribution of each of a series of known lengthening maneuvers remains incompletely characterized. OBJECTIVE: The aim of this study was to compare technical procedures for lengthening of the left colon before rectal anastomosis. DESIGN: A series of lengthening maneuvers was performed on 15 fresh cadavers. Mean distance gained was measured for each successive maneuver, including 1) high inferior mesenteric artery ligation, 2) splenic flexure takedown, and 3) high inferior mesenteric vein ligation by the ligament of Treitz. SETTING: Cadaveric study. MAIN OUTCOME MEASURES: The premobilization and postmobilization position of the proximal colonic end was measured relative to the inferior edge of the sacral promontory. Measurements of the colonic length relative to the sacral promontory were taken after each mobilization maneuver. The inferior mesenteric artery, sigmoid colon, and rectum specimen lengths were measured. The distance from the inferior border of the sacral promontory to the pelvic floor was measured along the sacral curvature. RESULTS: Mean sigmoid colon resection length was 34.7 ± 11.1 cm. Before any lengthening, baseline reach was -1.3 ± 4.2 cm from the sacral promontory. Inferior mesenteric artery ligation yielded an additional 11.5 ± 4.7 cm. Subsequent splenic flexure takedown added an additional 12.8 ± 9.6 cm. Finally, inferior mesenteric vein ligation added an additional 11.33 ± 6.9 cm, bringing the total colonic length to 35.7 ± 14.7 cm. BMI and weight negatively correlated with length gained. LIMITATIONS: The study was limited by nature of being a cadaver study. CONCLUSIONS: Stepwise lengthening maneuvers allow significant additional reach to allow a tension-free left colon to rectal anastomosis. See Video Abstract . ESTUDIO CADAVRICO DE MANIOBRAS DE ALARGAMIENTO COLNICO TRAS UNA SIGMOIDECTOMA: ANTECEDENTES:La creación de una anastomosis colorrectal libre de tensión tras una resección de colon izquierdo o tras una resección anterior baja es un requisito clave para el éxito relacionado con la técnica quirúrgica. La relativa contribución de las diversas maniobras de alargamiento permanece caracterizada de manera incompleta.OBJETIVO:El propósito de este estudio fue la de comparar procedimientos técnicos de alargamiento del colon izquierdo previo a la anastomosis rectal.DISEÑO:Una serie de maniobras de alargamiento fueron realizados en 15 cadáveres frescos. La distancia promedio ganada fue medida para cada maniobra sucesiva, incluyendo (1) ligadura alta de la arteria mesentérica inferior, (2) descenso del ángulo esplénico, (3) ligadura alta de la vena mesentérica interior mediante el ligamento de Treitz.AJUSTES:Estudio cadavérico.PRINCIPALES MEDIDAS DE RESULTADO:La posición premobilizacion y postmobilizacion del extremo proximal del colon fue medido tomando en cuenta el borde inferior del promontorio sacro. Las mediciones de la longitud colónica en relación al sacro fueron tomadas luego de cada maniobra de movilización. Fueron tomadas así mismo las longitudes de la arteria mesentérica inferior, el colon sigmoides y recto. Las distancias desde el borde inferior del promontorio sacro al suelo pelvico fueron medidas a lo largo de la curvatura sacra.RESULTADOS:Average sigmoid colon resection length was 34.7 ± 11.1 cm. Prior to any lengthening, baseline reach was -1.3 ± 4.2 cm from the sacral promontory. Inferior mesenteric artery ligation yielded an additional 11.5 ± 4.7 cm. Subsequent splenic flexure takedown added an additional 12.8 ± 9.6 cm. Finally, inferior mesenteric vein ligation added an additional 11.33 ± 6.9 cm, bringing the total colonic length to 35.7 ± 14.7 cm. BMI and weight negatively correlated with length gained.LIMITACIONES:Este estudio tuvo como limitación la naturaleza de haber sido un estudio cadavérico.CONCLUSIONES:Maniobras de alargamiento permiten un alcance adicional significativo permitiendo de esta manera una anastomosis de colon izquierdo a recto libre de anastomosis. (Traducción-Dr Osvaldo Gauto ).

Vascular variants in laparoscopic extended right hemicolectomy with central vascular ligation for right colon cancer.

PURPOSE: To evaluate the right colic vascularity, focusing on the confluences of veins. METHODS: The subjects of this retrospective study were 100 patients who underwent laparoscopic extended right hemicolectomy (Lap-ERHC) between April 2015 and September 2020, at our hospitals. Veins draining into the superior mesenteric vein (SMV) included the ileocecal vein (ICV), the right colic vein (RCV), the middle colic vein (MCV), and the gastrocolic trunk of Henle (GCT). Veins draining into vessels other than the SMV were defined as accessory colic veins (aICV, aRCV or aMCV). RESULTS: The GCT, aRCV, and aMCV were found in 86, 89, and 15 patients, respectively. In 66 patients with one aRCV, drainage was split as the anterior superior pancreaticoduodenal vein (ASPDV) in 12, the right gastroepiploic vein (RGEV) in 7, and the GCT in 47. In 23 patients with two aRCVs, drainage was split as the ASPDV in 4, the RGEV in 1, the GCT in 11, and the ASPDV and GCT in 7. In 14 patients with one aMCV, drainage was split as the GCT in 8, the splenic vein in 5, and the first jejunal vein (FJV) in 1. One patient had two aMCVs, draining into the GCT and the FJV. CONCLUSIONS: The findings of our evaluation of vascular anatomy, focusing on confluences of the colic veins, provides useful information for colorectal surgeons.

Anatomical study of the inferior mesenteric vein using three-dimensional computed tomography angiography in laparoscopy-assisted surgery for left-sided colorectal cancer.

PURPOSE: To investigate the drainage patterns of the inferior mesenteric vein (IMV) and measure the distance from the root of the inferior mesenteric artery (IMA) to the IMV using preoperative three-dimensional computed tomography (3D-CT) angiography in patients undergoing surgery for left-sided colorectal cancer. METHODS: In this retrospective study, we analyzed data collected prospectively on 167 consecutive patients who underwent laparoscopic left-sided colorectal cancer surgery between July, 2014 and August, 2019. The drainage pattern of the IMV and the distance from the root of the IMA to the IMV were evaluated using 3D-CT angiography. We also assessed intraoperative adverse events and postoperative outcomes. RESULTS: The IMV drained into the superior mesenteric vein (SMV) in 44 patients, into the confluence point of the SMV and splenic vein (SV) in 38 patients, into the SV in 83 patients, and into the middle colic vein in the remaining three patients. The median length from the root of the IMA to the IMV was 22.1 mm (1.3-84.9). IMV injury occurred in only one patient during surgery, but resulted in colonic ischemia. CONCLUSION: 3D-CT angiography is useful for the preoperative assessment of vascular anatomical variations of the IMV and IMA for safe intraoperative navigation and prevention of complications during laparoscopy-assisted left-sided colorectal surgery.

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

PURPOSE: In 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. METHODS: We 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. RESULTS: Accessory 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. CONCLUSION: 3D CT angiograms are useful for preoperative evaluation. Accessory middle colic arteries exist and were observed in 14.9% of cases.

[Laparoscopic radical resection of rectal cancer with preservation of the left colic artery: anatomical basis and surgical experience].

In order to increase the blood supply of anastomosis, surgeons choose to preserve the left colon artery (LCA) during the laparoscopic radical resection of rectal cancer. However, surgeons are always ailed by hemorrhage and incompletely dissection of No. 253 lymph nodes. One reason is the shortage of understanding the relationship between inferior mesenteric artery (IMA), LCA, and inferior mesenteric vein before surgery. Another reason is that surgeon always remove the lymph nodes around LCA, while don't normatively resect No. 253 lymph nodes, which affect the overall survival rate. Therefore, the "medial-to-lateral approach" for laparoscopic preservation with LCA radical resection in rectal cancer was suggested in this article. The CT technique could be used to analyze the IMA classification, which contribuated to the standard conservation of LCA. Laparoscopic radical resection of rectal cancer could be completed of high quality, through accurate definition and exactly dissection of the No. 235 lymph nodes.

Vascular anatomy of the transverse mesocolon and bidirectional laparoscopic D3 lymph node dissection for patients with advanced transverse colon cancer.

Laparoscopic D3 lymph node dissection for transverse colon cancer is technically demanding because of complicated anatomy. Here, we reviewed the vascular structure of the transverse mesocolon, explored the extent of the base of the transverse mesocolon, and evaluated the feasibility and oncological safety of D3 lymph node dissection. We retrospectively reviewed the clinical records of 42 patients with advanced transverse colon cancer who underwent curative surgery and D3 dissection at Kyushu University Hospital between January 2008 and December 2015. We examined the venous and arterial anatomy of the transverse mesocolon of each resection and compared surgical outcomes between patients who underwent laparoscopic D3 (Lap D3) and open D3 (Open D3) dissection. Patients included two with Stage I, 18 with Stage II, 20 with Stage III, and two with Stage IVA. Thirty-six (85.7%) and six (14.3%) patients underwent Lap D3 or Open D3, respectively. The tumor sizes of the Open D3 and Lap D3 groups were 7.8 and 3.7 cm, respectively (P < 0.001). The Lap D3 group had significantly less blood loss (26 mL vs 272 mL, P = 0.002). The other outcomes of the two groups were not significantly different, including 3-year overall survival (87.7% vs 83.3%, P = 0.385). We observed four patterns of the middle colic artery (MCA) arising from the superior mesenteric artery (SMA), and the frequency of occurrence of a single MCA was 64.3%. The right-middle colic vein (MCV) was present in 92.9% of resections and served as a tributary of the gastrocolic trunk, and 90.5% of the left MCVs drained into the superior mesenteric vein (SMV). The root of the transverse mesocolon was broadly attached to the head of the pancreas and to the surfaces of the SMV and SMA. Laparoscopic D3 lymph node dissection may be tolerated by patients with advanced transverse colon cancer.

Variant termination of first and second jejunal veins into a "pancreatic portal vein".

Jejunal veins usually terminate into the superior mesenteric vein. Here, an unusual termination of first and second jejunal veins into a pancreatic portal vein has been presented. The common vein formed by the first and second jejunal veins could be named as pancreatic portal vein because it divided into two branches in front of the third part of the duodenum and these two branches entered the head of the pancreas and further divided into smaller branches before anastomosing with the tributaries of pancreatico-duodenal veins. The knowledge of this rare vein could be useful to radiologists and surgeons.

Gastrocolic trunk of Henle and its variants: review of the literature and clinical relevance in colectomy for right-sided colon cancer.

PURPOSE: Venous vascular anatomy of the right colon presents a high degree of variability. Henle's Gastrocolic Trunk is considered an important anatomical landmark by colorectal surgeons. The classical description concerns a bipod vascular structure or tripod, but several variants are associated to it. The aim of this study is to merge the most updated literature on the anatomy knowledge of the Gastrocolic Trunk by evaluating all possible variants, as well as to underline its surgical importance due to its topographical relationships. METHODS: Twelve studies describing the anatomy of the gastrocolic trunk were selected, each of them dealing with a more or less extensive series of cases. A distinction was drawn between the gastropancreatic trunk, devoid of the colonic component, and the gastrocolic trunk; and then the frequency of the different resulting variants was reported. The data obtained from cadavers and radiological studies were analyzed separately. RESULTS: The Gastrocolic Trunk is found in 74% of cadaver studies, and in 86% of radiological studies. Its most frequent configuration is represented by the union of right gastroepiploic vein + anterior superior pancreaticoduodenal vein + superior right colic vein, respectively, 32.5% and 42.5%, followed by the right colic vein which replaces (26.9%, 12.3%) or is added (10%, 20.1%) to the superior right colic vein. CONCLUSIONS: The superior right colic vein joins the right gastroepiploic vein and the anterior superior pancreaticoduodenal vein thus forming, in most cases, the gastrocolic trunk. The anatomical knowledge of vascular structures forms the basis for both the interpretation of preoperative radiological images and the surgical procedure itself, despite the considerable anatomical variability of tributaries.

[Clinical anatomy study of superior mesenteric vessels and its branches].

Objective: To examine the anatomical relationships of tributaries to superior mesenteric artery and vein in surgical procedures. Methods: A prospectively designed observational trial, registried to Chinese Clinical Trial Registry, ChiCTR 1800014610, was conducted in Department of General Surgery, Peking Union Medical College Hospital from July 2016 to Decmeber 2018 to record the relationships of ileocolic artery and vein, right colic artery and vein, middle colic artery and vein, and combinations to assemble Henle's trunk, during the laparoscopic operation of radical right colectomy for right colon malignancies. The length of middle colic artery, length of Henle's trunk, and distance from Henle's trunk to the inferior margin of pancreatic head to duodenum were measured during operation. A total of 100 patients, 52 male and 48 female, with right colon cancer, who underwent radical right colectomy, were enrolled in present study from July 2016 to December 2018, with age of (61.0±12.3) years (range: 31 to 82 years), and body mass index of (23.3±3.5) kg/m(2) (range: 16.0 to 34.2 kg/m(2)). Results: The ileocolic artery and vein presented as rates of 97.0% (97/100, 95%CI: 91.5% to 99.4%, the same below) and 98.0% (98/100, 93.0% to 99.8%), respectively. The ileocolic vein ran ventrally in 51 of 97 patients (52.6%, 42.7% to 62.5%). The right colic artery, which raised from superior mesenteric artery directly, was found in 42 of 100 patients (42.0%, 32.3% to 51.7%); and the right colic vein drained directly into superior mesenteric vein in 19 of 100 patients (19.0%, 11.3% to 26.7%). The presence of middle colic artery and vein were 95.0% (95/100, 90.7% to 99.3%) and 90.0% (90/100, 84.1% to 95.9%) respectively. The average length of middle colic artery, from its origin to bifurcation into right and left branches, was (2.6±1.6) cm (range: 0.1 to 7.2 cm). All the dissected middle colic vein drained into superior mesenteric vein (87.8% (79/90), 81.0% to 94.6%) and Henle's trunk (12.2% (11/90), 5.4% to 19.0%). Henle's trunk was found in 93 of 100 patients (93.0%, 88.0% to 98.0%), with average length of (1.0±0.6) cm (range: 0.1 to 2.4 cm). The distance between Henle's trunk to the inferior margin of pancreatic head was (2.7±0.7) cm (range: 1.3 to 4.5 cm). More than half of the Henle's trunk were composed of 3 tributaries (54.8% (53/93), 40.8% to 61.2%). The most frequently discovered tributaries to form Henle's trunk were right gastroepiploic vein (98.0% (98/100), 93.0% to 99.8%), superior right colic vein (82.0% (82/100), 74.5% to 89.5%), and superior anterior pancreaticoduodenal vein (78.0% (78/100), 69.9% to 86.1%). In present study, the right branch of middle colic vessels was often found to run closely with Henle's trunk, veins drained from small intestine could be found to run over superior mesenteric artery to converge into superior mesenteric vein. There were 2 incidences, injuries to Henle's trunk and middle colic vein, happened during the operation, which were overcomed by bipolar coagulation and dividing the vessels. Conclusions: Ileocolic vessels and middle colic vessels could be used as landmarks for laparoscopic surgery based on their constant anatomical existence. In contrast, the chances are rare for the presence of right colic artery or right colic vein. Nearly half of the Henle's trunk was consisted of right gastroepiploic vein, superior right colic vein and superior anterior pancreaticoduodenal vein. Exceptional cautions should be made for the variations of the Henle's trunk during the operation.

The venous trunk of henle (gastrocolic trunk): A systematic review and meta-analysis of its prevalence, dimensions, and tributary variations.

Surgeons have recognized the clinical significance of the venous trunk of Henle during multiple pancreatic, colorectal, and hepatobiliary procedures. To date, no study has followed the principles of evidence-based anatomy to characterize it. Our aim was to find, gather, and systematize available anatomical data concerning this structure. The MEDLINE/PubMed, ScienceDirect, EMBASE, BIOSIS, SciELO, and Web of Science databases were searched. The following data were extracted: prevalence of the trunk of Henle, its mean diameter and length, the organization of its tributaries, method of anatomical assessment (cadaveric, radiological, or intraoperative), geographical origin, study sample, and known health status. Our search identified 38 records that included data from 2,686 subjects. Overall, the prevalence of the trunk of Henle was 86.9% (95% CI, 0.81-0.92) and the mean diameter was 4.2 mm. Only one study reported the length of the trunk (10.7 mm). The most common type of venous trunk (56.1%) was a vessel comprising three tributaries: gastric (right gastro-epiploic vein), pancreatic (most commonly the anterior superior pancreaticoduodenal vein), and colic (most commonly the superior right colic vein). The trunk of Henle is a common variant in the anatomy of the portal circulation. It is a highly variable vessel, but the most common type is a gastro-pancreato-colic trunk. In surgical practice, the presence of this venous trunk poses a high risk for bleeding, but it can also be a useful landmark during various abdominal procedures. Clin. Anat. 31:1109-1121, 2018. © 2018 Wiley Periodicals, Inc.

Intraoperative Archive of Right Colonic Vascular Variability Aids Central Vascular Ligation and Redefines Gastrocolic Trunk of Henle Variants.

BACKGROUND: Vascular supply to the right colon has become an issue because of high variability and subsequent impact on minimally invasive surgery. Past cadaveric or radiologic anatomic assessments are noncomprehensive. OBJECTIVE: Intraoperative charting of right colonic arteriovenous anatomy was undertaken to determine the incidence and scope of vascular variations. DESIGN: Vascular anatomy variations were documented in snapshot images, captured during laparoscopic video recordings or through open surgical digital photography. SETTINGS: Data were drawn from consecutive right hemicolectomies, routinely entailing complete mesocolic excision with central vascular ligation. PATIENTS: Seventy patients (mean age, 62.7 years; 37 women (52.8%); 33 men (47.2%)), each with surgically treatable right-sided colon cancer, were prospectively studied. RESULTS: Both ileocolic and middle colic arteries were regularly identified (100%), with right colic artery present in 41.4% of patients. Ileocolic and middle colic veins consistently drained into the right colon. Although the ileocolic vein always emptied into the superior mesenteric vein, drainage of the middle colic vein was split (superior mesenteric vein, 94.3%; gastrocolic trunk of Henle, 5.3%), as was drainage of the right colic (superior mesenteric vein, 43.3%; gastrocolic trunk of Henle, 56.7%) and accessory middle colic veins (superior mesenteric vein, 54.5%; gastrocolic trunk of Henle, 45.5%), present in 42.9% and 15.7% of patients. Gastrocolic trunk of Henle was found in 88.6% of patients, usually draining into the superior mesenteric vein. No significant sex-related differences were present regarding the incidence and scope of variability displayed by the right colic artery, right colic vein, accessory middle colic vein, or gastrocolic trunk of Henle classification (p > 0.05). LIMITATIONS: The inconsistency between cadaver and live surgery anatomy and the low BMI of the Asian population might be drawbacks of our study. CONCLUSIONS: Variations in right colonic arteriovenous channels, assessed intraoperatively, corroborate those established by cadaveric and radiologic means, prompting a new gastrocolic trunk of Henle classification.

Evaluation of the vascular anatomy of the right-sided colon using three-dimensional computed tomography angiography: a single-center study of 536 patients and a review of the literature.

PURPOSE: The requisite for a rigorous preoperative understanding of vascular branching continues to grow in parallel with the implementation of laparoscopic surgery. Three-dimensional (3D)-computed tomography (CT) angiography is a less-invasive modality than traditional angiographic examination. Therefore, we aimed to evaluate branching patterns of the superior mesenteric artery (SMA). METHODS: In the present study, 536 consecutive patients who underwent preoperative 3D-CT angiography from April 2012 to March 2014 were prospectively enrolled. The branching pattern of the right colic artery (RCA) and the intersectional patterns of the RCA, ileocolic artery (ICA), and superior mesenteric vein (SMV) were evaluated. RESULTS: The RCA existed in only 179 cases (33.4 %); the remaining 357 patients (66.6 %) lacked evidence of the RCA. The ICA was detected in all cases. The RCA ran ventral to the SMV in the majority of cases (89.4 %). Conversely, the ICA ran ventral to the SMV in only half of the cases (50.6 %). When the RCA was observed to pass dorsal to the SMV, the ICA also ran dorsal to SMV in all cases. CONCLUSIONS: 3D-CT angiography can aid surgeons in identifying and understanding the anatomical vascular variations and intersectional patterns of the RCA, ICA, and SMV. Developing awareness of these variations can aid in the prevention of unexpected vascular injury during laparoscopic right-sided colon surgery.

Anatomy of the transverse colon revisited with respect to complete mesocolic excision and possible pathways of aberrant lymphatic tumor spread.

PURPOSE: Although lymph node metastases to pancreatic and gastroepiploic lymph node stations in transverse colon cancer have been described, the mode of lymphatic spread in this area remains unclear. This study was undertaken to describe possible pathways of aberrant lymphatic spread in the complex anatomic area of the proximal superior mesenteric artery and vein, the greater omentum, and the lower pancreatic border. METHODS: Abdominal specimens obtained from four cadaveric donors were dissected according to the principles of complete mesocolic excision. The vascular architecture of the transverse colon was scrutinized in search of possible pathways of lymphatic spread to the pancreatic and gastroepiploic lymph nodes. RESULTS: Vascular connections between the transverse colon and the greater omentum at the level of both the hepatic and the splenic flexures could be identified. In addition, small vessels running from the transverse mesocolon to the lower pancreatic border in the area between the middle colic artery and the inferior mesenteric vein were demonstrated. Moreover, venous tributaries to the gastrocolic trunk could be exposed to highlight its surgical importance as a guiding structure for complete mesocolic excision. CONCLUSION: The technical feasibility to clearly separate embryologic compartments by predefined tissue planes in complete mesocolic excision was confirmed. However, the vicinity of all three endodermal intestinal segments (foregut, midgut, and hindgut) obviously gives way to vascular connections that might serve as potential pathways for lymphatic metastatic spread of transverse colon cancer.

Bowel function and quality of life after superior mesenteric nerve plexus transection in right colectomy with D3 extended mesenterectomy.

BACKGROUND: The aim of this study was to ascertain the impact of injury to the superior mesenteric nerve plexus caused by right colectomy with D3 extended mesenterectomy as performed in the prospective multicenter trial: "Safe Radical D3 Right Hemicolectomy for Cancer through Preoperative Biphasic Multi-detector Computed Tomography" in which all soft tissue surrounding the superior mesenteric vessels from the level of the middle colic artery to that of the ileocolic artery was removed. METHODS: Bowel function and gastrointestinal quality of life in two consecutive cohorts that underwent right colectomy with and without D3 extended mesenterectomy were compared. Main outcome measures were the Diarrhea Assessment Scale (DAS) and Gastrointestinal Quality of Life Index (GIQLI). The data were collected prospectively through telephone interviews. RESULTS: Forty-nine patients per group, comparable for age, sex, length of bowel resected but with significantly shorter follow-up time in the experimental group, were included. There was no difference in total DAS scores, subscores or additional questions except for higher bowel frequency scores in the D3 group (p = 0.02). Comparison of total GIQLI scores and subscales showed no difference between groups. Regression analysis with correction for confounding factors showed 0.48 lower bowel frequency scores in the D2 group (p = 0.022). Within the D3 group presence of jejunal arteries cranial to the D3 dissection area showed 1.78 lower DAS scores and 0.7 lower bowel frequency scores. CONCLUSIONS: Small bowel denervation after right colectomy with D3 extended mesenterectomy leads to increased bowel frequency but does not impact gastrointestinal quality of life. Individual anatomical variants can affect postoperative bowel function differently despite standardized surgery.

Classification of portal vein tributaries in Thai cadavers including a new type V.

PURPOSE: To compare portal vein tributaries in Thai with Thompson classification. METHODS: In 211 Thai cadavers, abdominal regions were dissected to identify the portal veins and their tributaries. The subjects were classified into types based on modes of drainage of the left gastric and inferior mesenteric veins. Percentages of all types of venous drainage were counted. RESULTS: There are four types of portal tributaries as defined by Thompson, type I_47.87 %, type II_13.27 %, type III_7.58 %, and type IV_29.86 %. There were 1.42 % of whose inferior mesenteric veins entered the joining angle of the superior mesenteric and splenic veins, and were classified as type V. The left gastric vein mostly drained into the portal vein in 79.15 %, while the inferior mesenteric vein emptied into the splenic vein mainly in 55.45 %. CONCLUSIONS: A new variance of portal tributaries in Thai cadavers is reported. The variations of portal vein formations are critical for liver surgery and interventional radiological procedures.

Vascular anatomy of the small intestine-a comparative anatomic study on humans and pigs.

BACKGROUND: Porcine models are well established for studying intestinal anastomotic healing. In this study, we aimed to clarify the anatomic differences between human and porcine small intestines. Additionally, we investigated the influences of longitudinal and circular sutures on human small intestine perfusion. METHODS: Intestines were obtained from human cadavers (n = 8; small intestine, n = 51) and from pigs (n = 10; small intestine, n = 60). Vascularization was visualized with mennige gelatin perfusion and high-resolution mammography. Endothelial cell density was analyzed with immunohistochemistry and factor VIII antibodies. We also investigated the influence of suture techniques (circular anastomoses, n = 19; longitudinal sutures, n = 15) on vascular perfusion. RESULTS: Only human samples showed branching of mesenteric vessels. Compared to the pig, human vessels showed closer connections at the entrance to the bowel wall (p = 0.045) and higher numbers of intramural anastomoses (p < 0.001). Porcine main vessels formed in multifilament-like vessel bundles and displayed few intramural vessel anastomoses. Circular anastomoses induced a circular perfusion defect at the bowel wall; longitudinal anastomoses induced significantly smaller perfusion defects (p < 0.001). Both species showed higher vascular density in the jejunum than in the ileum (p < 0.001). Human samples showed similar vascular density within the jejunum (p = 0.583) and higher density in the ileum (p < 0.001) compared to pig samples. CONCLUSION: The results showed significant differences between human and porcine intestines. The porcine model remains the standard for studies on anastomotic healing because it is currently the only viable model for studying anastomosis and wound healing. Nevertheless, scientific interpretations must consider the anatomic differences between humans and porcine intestines.

Navigating the mesentery: a comparative pre- and per-operative visualization of the vascular anatomy.

AIM: Awareness of anatomy is critical for performing safe surgery within the root of the mesentery. Our aim was to investigate the anatomical relationship between the superior mesenteric artery (SMA) and vein (SMV) and their branches within a predefined D3 area of the right colon and to compare preoperatively established three-dimensional (3D) mesenteric vessel anatomy from CT with that found at surgery. METHOD: Prospective data were collected on 139 patients included in the 'Safe Radical D3 Right Hemicolectomy for Cancer Through Preoperative Biphasic Multi-detector Computed Tomography (MDCT) Angiography' trial. CT data sets were 3D reconstructed before surgery and compared with photographs taken during the operation. RESULTS: The ileocolic artery was present and correctly identified in all patients and crossed the SMV anteriorly in 58 (41.7%). Seventeen patients had a right colic artery at surgery and there were three false-negative and one false-positive CT findings, yielding a diagnostic accuracy of 97.1%, sensitivity of 85.7% and specificity of 95.2%. Positive and negative predictive values were 94.7% and 97.5%, respectively. The middle colic artery was absent in one (0.7%) patient and multiple (nine double and one triple) in 10 (7.2%) patients. A mean of 3.8 ± 1.2 jejunal arteries and 2.0 ± 0.8 jejunal veins arose from the SMA and SMV. Jejunal veins crossed the SMA in the D3 area anteriorly in 30.9% of patients. In 26 (18.7%) patients, additional veins drained into the SMV, including pancreaticoduodenal in 16, right colic in six and both in two. The inferior mesenteric vein entered the SMV in 58 (41.7%) patients and crossed the D3 area in three (2.2%). CONCLUSION: CT-reconstructed anatomy has high specificity, sensitivity, accuracy and reliability.

Lymph node distribution in the d3 area of the right mesocolon: implications for an anatomically correct cancer resection. A postmortem study.

BACKGROUND: Data on lymph node distribution in the right colon D3 area are scarce, especially for nodes posterior to the superior mesenteric vessels. OBJECTIVE: The aim of this study was to determine whether nodes exist posterior to the superior mesenteric vessels and if arterial crossing patterns affect node distribution. DESIGN: This is an anatomical postmortem study. SETTINGS: This study was conducted at the following institutions: Department of Gastrointestinal surgery/Pathology, Vestfold Hospital Trust, Norway; Institute for Pathology, University of Belgrade, Serbia; and Anatomy Sector, University of Geneva, Switzerland. PATIENTS: Fresh human cadavers were selected to undergo autopsy. INTERVENTION: A predefined D3 area was removed from cadavers, fixed in formaldehyde, divided into 3 vertical compartments with regard to the superior mesenteric vessels. Vertical compartments were further divided into 8 compartments. Millimeter slices were analyzed at histology. MAIN OUTCOME MEASURES: Lymph nodes ≥1 mm were counted in each compartment. RESULTS: Twenty-six cadavers (14 men), median age 76 years, were included. Mean node number per cadaver was 15.9 ± 7.4. Lateral, anterior, and posterior vertical compartments contained median 5.5 (1-11), 5 (2-21), and 5 (0-11) nodes. The effect of the ileocolic artery crossing pattern on node number in the posterior vertical compartment was p = 0.020. Anterior/posterior ileocolic artery compartments contained nodes in 58% and 85% cadavers with median of 1(0-7) and 2(0-5). These compartments showed a significant difference in node numbers depending on the ileocolic artery crossing pattern, p < 0.001 (posterior crossing) and p < 0.001 (anterior crossing). The middle colic artery compartment contained nodes in all cadavers with a median of 2 (1-4). The association between volume and total number of nodes in the D3 area was statistically significant, p < 0.001. LIMITATIONS: Nodes posterior to the superior mesenteric vessels do not necessarily have clinical relevance. CONCLUSION: Anatomically correct D3 resection implies posterior vertical compartment removal with posterior ileocolic artery crossing. Addition of the lateral vertical compartment to routine right colectomy has an improvement potential of 5 to 6 nodes.

Anatomical basis of laparoscopic medial-to-lateral mobilization of the descending colon.

In laparoscopic colorectal resection, the medial-to-lateral approach has been largely adopted. This approach can be initiated by the division of either the inferior mesenteric artery (IMA) or the inferior mesenteric vein (IMV). This cadaveric study aimed to establish the feasibility of IMV dissection as the initial landmark of medial-to-lateral left colonic mobilization for evaluating the size of the peritoneal window between the IMV at the lower part of the pancreas and the origin of the IMA (IMA-IMV distance) and the point of origin of the IMA compared to the lower edge of the third part of the duodenum (IMA-D3 distance). These distances were recorded on 30 fresh cadavers. The IMA-D3 distance was 0.4 ± 2.2 cm (mean ± SD). The IMA originated from the aorta at the level of or below the D3 in 21 cases (70%). The IMA-IMV distance was 5.5 ± 1.8 cm and was greater or equal to 5 cm (large window) in 21 cases (70%). IMA-IMV distance was correlated with IMA-D3 showing that a large window was inversely correlated with a low IMA origin (P < 0.001). IMA-D3 distance was not correlated with weight, height and sex. IMA-IMV distance was largerin male (6.7 ± 0.9 vs. 4.9 ± 1.8, P = 0.001) and correlated with weight, (r = 0.60, 95%CI = 0.03-0.10, P < 0.001) and height (r = 0.54, 95%CI = 0.05-0.21, P = 0.002). IMV can be used as the initial landmark for laparoscopic medial-to-lateral dissection in two-thirds of cases. A too-small window can require first IMA division. The choice between the two different medial-to-lateral approaches could be made by evaluating the anatomical relationship between IMA, IMV, and D3.