Variaciones anatómicas en la vascularización del colon derecho y su implicancia en la escisión completa del mesocolon con linfadenectomía D3. Estudio de corte transversal / Anatomical variations in right colon vascularization: its implication in complete mesocolic excision with D3 lymphadenectomy. A cross-sectional study

Introducción: La escisión completa del mesocolon con linfadenectomía D3 (CME-D3) mejora los resultados de los pacientes operados por cáncer del colon. Reconocer adecuadamente la anatomía vascular es fundamental para evitar complicaciones. Objetivo: El objetivo primario fue determinar la prevalencia de las variaciones anatómicas de la arteria mesentérica superior (AMS) y sus ramas en relación a la vena mesentérica superior (VMS). El objetivo secundario fue evaluar la asociación entre las distintas variantes anatómicas y el sexo y la etnia de lo pacientes. Diseño: Estudio de corte transversal. Material y métodos: Se incluyeron 225 pacientes con cáncer del colon derecho diagnosticados entre enero 2017 y diciembre de 2020. Dos radiólogos independientes describieron la anatomía vascular observada en las tomografías computadas. Según la relación de las ramas de la AMS con la VMS, la población fue dividida en 2 grupos y subdividida en 6 (1a-c, 2a-c). Resultados: La arteria ileocólica fue constante, transcurriendo en el 58,7% de los casos por la cara posterior de la VMS. La arteria cólica derecha, presente en el 39,6% de los pacientes, cruzó la VMS por su cara anterior en el 95,5% de los casos. La variante de subgrupo más frecuente fue la 2a seguida por la 1a (36,4 y 24%, respectivamente). No se encontró asociación entre las variantes anatómicas y el sexo u origen étnico. Conclusión: Las variaciones anatómicas de la AMS y sus ramas son frecuentes y no presentan un patrón predominante. No hubo asociación entre las mismas y el sexo u origen étnico en nuestra cohorte. El reconocimiento preoperatorio de estas variantes mediante angiotomografía resulta útil para evitar lesiones vasculares durante la CME-D3. (AU)

Background: Complete mesocolic excision with D3 lymphadenectomy (CME-D3) improves the outcomes of patients operated on for colon cancer. Proper recognition of vascular anatomy is essential to avoid complications. Aim: Primary outcome was to determine the prevalence of anatomical variations of the superior mesenteric artery (SMA) and its branches in relation to the superior mesenteric vein (SMV). Secondary outcome was to evaluate the association between these anatomical variations and sex and ethnicity of the patients. Design: Cross-sectional study. Material and methods: Two hundred twenty-fivepatients with right colon cancer diagnosed between January 2017 and December 2020 were included. Two independent radiologists described the vascular anatomy of computed tomography scans. The population was divided into 2 groups and subdivided into 6 groups (1a-c, 2a-c), according to the relationship of the SMA and its branches with the SMV. Results: The ileocolic artery was constant, crossing the SMV posteriorly in 58.7% of the cases. The right colic artery, present in 39.6% of the patients, crossed the SMV on its anterior aspect in 95.5% of the cases. The most frequent subgroup variant was 2a followed by 1a (36.4 and 24%, respectively). No association was found between anatomical variants and gender or ethnic origin. Conclusions: The anatomical variations of the SMA and its branches are common, with no predominant pattern. There was no association between anatomical variations and gender or ethnic origin in our cohort. Preoperative evaluation of these variations by computed tomography angi-ography is useful to avoid vascular injuries during CME-D3. (AU)

Surgical anatomy of the dorsal pancreatic artery: Considering embryonic development.

OBJECTIVES: The 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. METHODS: This study included 110 patients who underwent computed tomography scans. We examined the pathways and branching patterns of the DPA. RESULTS: The 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. CONCLUSION: A 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.

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.

Arterial branching pattern of the cranial mesenteric artery in the degu (Octodon degus).

BACKGROUND: The cranial mesenteric artery exhibits a species-specific ramification pattern that adapts to the morphology of the intestinal tract. The degu is a strictly herbivorous rodent with a well-developed large intestine with a spiral loop in the ascending colon; therefore, the cranial mesenteric artery likely demonstrates a degu-specific ramification pattern. Thus, we traced the cranial mesenteric artery to establish the detailed ramification pattern of the branches. METHODS: Eighteen male degus were injected with 0.3-0.8 ml of a latex mixture and water at a 1:1 ratio in conjunction with red acrylic paint coloring using a catheter inserted into the thoracic aorta. The cranial mesenteric artery was traced using a surgical microscope and photographed using a digital camera. RESULTS: The arteries emerging from the cranial mesenteric artery exhibited frequent variations in number, distribution area, anastomosis pattern, and branching order. In the most frequent cases (22%), the cranial mesenteric artery sequentially gave rise to caudal pancreaticoduodenal, middle colic, right colic, jejunal, and ileocolic arteries. The right and middle colic arteries exhibited four different ramification patterns. In the most common cases (67%), the middle and right colic arteries emerged independently from the cranial mesenteric artery. The former was distributed to the transverse and descending colon, whereas the latter sent branches to the spiral loop of the ascending colon. CONCLUSIONS: The complex ramification pattern of the right colic artery in the degu may be an adaptation to the characteristic running pattern of the ascending colon. Thus, we present the first comprehensive report of the arterial branching pattern of the cranial mesenteric artery in the degu.

Angiographic characteristics of the intermesenteric artery.

PURPOSE: The literature reports the presence of the intermesenteric artery (IA), an anastomosis connecting the superior mesenteric artery (SMA) to the inferior mesenteric artery (IMA) in 9-18% of human cadaver dissections. This is the first study describing the morphological and demographic characteristics of the IA based on in vivo imaging. METHODS: A total of 150 consecutive abdominal computed tomography (CT) angiographies of adult patients identified by sex and age were analyzed. The IA was assessed for its presence, point of origin, pathway, point of insertion, and diameter at its origin. The diameters of the SMA, IMA, and other arteries from which the IA originated and into which it inserted were measured by CT angiography using Radiant™ and Osirix MD™ software. RESULTS: The IA was found in 17 (51.5%) of the females and 60 (51.3%) of the males. The diameters of the SMA and IMA were larger in the males than in the females, but there was no sex difference in the diameter of the IA. The diameter of the SMA was larger than that of the IMA, and the diameter of the IA was smaller than that of the other arteries evaluated. An IA connecting the SMA and IMA trunks was found in 25.9% of the cases, while other connections between the branches of those trunks through an IA occurred less frequently. CONCLUSIONS: The intermesenteric artery is more frequently found than the literature refers and in most of cases directly connects the upper and lower arterial mesenteric circulations.

Tratamiento de la isquemia mesentérica crónica mediante técnica ROMS y uso de catéter de reentrada / Treatment of chronic mesenteric ischemia using ROMS technique and reentry catheter

Presentamos el caso de una paciente de 74 años con historia de isquemia mesentérica crónica asociada a múltiples comorbilidades que fue llevada a la sala hemodinámica para revascularización endovascular, que no fue efectiva, por lo que se decidió la realización de una laparotomía y retrograde open mesenteric stenting (ROMS). Durante el procedimiento se realizó una disección, para la que se utilizó el catéter de reentrada Outback® Elite. Se logró acceder al espacio luminal y posteriormente se implantó con éxito un stent, con lo que se obtuvo un adecuado paso de medio de contraste y la resolución de la oclusión.(AU)

We present the case of a 74-year-old patient with a history of chronic mesenteric ischemia with multiple comorbidities, which was taken to the hemodynamic room for endovascular revascularization which was not possible, so it is decided to make laparotomy and Retrograde Open Mesenteric Stenting (ROMS), presenting a dissection during the procedure for which the Outback® Elite re-entry catheter is used, achieving access to the true lumen and subsequently the successful deployment of a stent, getting adequate flow of contrast medium and resolution of the occlusion.(AU)

Reconstructing topography and extent of injury to the superior mesenteric artery plexus in right colectomy with extended D3 mesenterectomy: a composite multimodal 3-dimensional analysis.

BACKGROUND: Superior mesenteric artery plexus (SMAP) injury is reported to cause postoperative intractable diarrhea after pancreatic/colonic surgery with extended lymphadenectomy. This study aims to describe the SMAP microanatomy and extent of injury after right colectomy with extended D3 mesenterectomy for cancer. METHODS: Three groups (I) anatomical dissection, (II) postmortem histology, and (III) surgical specimen histology were included. Nerve count and area were compared between groups II and III and paravascular sheath thickness between groups I and II. 3D models were generated through 3D histology, nanoCT scanning, and finally through 3D printing. RESULTS: A total of 21 specimens were included as follows: Group (I): 5 (3 females, 80-93 years), the SMAP is a complex mesh surrounding the superior mesenteric artery (SMA), branching out, following peripheral arteries and intertwining between them, (II): 7 (5 females, 71-86 years), nerve count: 53 ± 12.42 (38-68), and area: 1.84 ± 0.50 mm2 (1.16-2.29), and (III): 9 (5 females, 55-69 years), nerve count: 31.6 ± 6.74 (range 23-43), and area: 0.889 ± 0.45 mm2 (range 0.479-1.668). SMAP transection injury is 59% of nerve count and 48% of nerve area at middle colic artery origin level. The median values of paravascular sheath thickness decreased caudally from 2.05 to 1.04 mm (anatomical dissection) and from 2.65 to 1.17 mm (postmortem histology). 3D histology models present nerve fibers exclusively within the paravascular sheath, and lymph nodes were observed only outside. NanoCT-derived models reveal oblique nerve fiber trajectories with inclinations between 35° and 55°. Two 3D-printed models of the SMAP were also achieved in a 1:2 scale. CONCLUSION: SMAP surrounds the SMA and branches within the paravascular sheath, while bowel lymph nodes and vessels lie outside. Extent of SMAP injury on histological slides (transection only) was 48% nerve area and 59% nerve count. The 35°-55° inclination range of SMAP nerves possibly imply an even larger injury when plexus excision is performed (lymphadenectomy). Reasons for later improvement of bowel function in these patients can lie in the interarterial nerve fibers between SMA branches.

Classification of the superior mesenteric artery.

The aim of this study was to characterize the branching pattern and morphology of the superior mesenteric artery (SMA), and also to create a new SMA classification, which seems necessary for clinicians performing surgery in this anatomical area. The anatomical variations in the branching patterns of the SMA were examined in 30 cadavers fixed in 10% formalin. Morphometric measurements were then obtained twice by two researchers. In the proposed classification system, Type I, characterized by all normal branches-inferior pancreatoduodenal artery, ileocolic artery, right colic artery, middle colic artery and intestinal arteries-occurred in 53.33% of the specimens. Type II, characterized by absence of the inferior pancreatoduodenal artery, was present in 26.67%. Type III, characterized by absence of the right colic artery, was present in 3.33%. Type IV, characterized by a common trunk for the inferior pancreatoduodenal artery and middle colic arteries, was observed in 3.33%. Type V, characterized by an aberrant hepatic artery and absence of the inferior pancreatoduodenal artery, was observed in 13.33%. The origin of the SMA was at the Th12/L1 level in 10% of cases, at L1 in 43.33%, at L1/L2 in 36.67%, and at L2 in 10%. The SMA is characterized by high morphological variability, the variants being associated with distinct clinical aspects. The introduction of a new, structured, anatomical classification seems necessary for all clinicians.

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.

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.

Prepancreatic common hepatic artery arising from superior mesenteric artery: an exceptional but important finding during pancreaticoduodenectomy.

PURPOSE: The hepato-mesenteric trunk is an extremely rare condition in which the common hepatic artery (CHA) originates from the superior mesenteric artery (SMA). Usually, CHA passes behind the head of the pancreas. A systematic review was performed to provide guidelines for the perioperative management of patients with this anatomical variation who underwent a pancreaticoduodenectomy (PD). A case report was also included. METHODS: A systematic search of the literature was conducted and the manuscript was structured following point-by-point the PRISMA guidelines. The risk of bias within individual studies was assessed using the Joanna Briggs Institute Critical Appraisal Checklist tools. Case report was structured according to the CARE guidelines. RESULTS: After an initial selection of 141 titles, 9 articles were included in the study (n = 10 patients). A postoperative surgical complication which required a reintervention occurred only one time. In four patients, CHA had a posterior position relative to pancreas, while in three cases, it was anterior. The remaining three patients had an intrapancreatic course. The CHA was resected in two patients, with an end-to-end reconstruction or using the splenic artery stump. In only three patients, a preoperative multidisciplinary presentation was performed and in four cases, the CHA variation was not described by radiologists in formal CT-scan reports. CONCLUSION: Although there are no definitive guidelines, improvements in the preoperative knowledge of such a rare anatomical variation may ensure better postoperative outcomes, avoiding intraoperative accidents and life-threatening postoperative complications.

Morphological speculation of the MHPD and related clinical projections.

OBJECTIVE: The concept of mesopancreas has been brought into focus nowadays. Studies on membrane morphology of pancreas are clinically significant in determining an ideal surgical route for a "holy plane". In this paper, we aimed to observe the structure of the peripancreatic membranes and its interactions with adjacent tissues; tentatively put forward the proposition of mesohepatopancreaticoduodenum (MHPD) and explore in depth in surgical local resection. METHODS: 33 cadavers were examined in the experiment, including 30 for gross anatomy and 3 for histological observation after transection. The histological characteristics of the membrane covering the pancreas were proved by Masson and Bielschowsky silver staining and further explored in clinical application and testified in a surgical scenario. All above were carried out through traditional procedures. RESULTS: The anterior surface membrane of the pancreas was intact and the posterior portion expanding to the pancreaticoduodenum enclosed the surface of the duodenum and the pancreatic head, which could be easily isolated from the posterior abdominal wall. The posterior surface membrane around the body and tail wrapped the pancreatic parenchyma, which created a soft-tissue window for the posterior abdominal wall. Then, dense connective tissue adhesions were detected between the celiac artery and the superior mesenteric artery. CONCLUSIONS: The embryonic origin of the mesopancreas and the surgical procedures were reviewed and inspected based on the proposition of MHPD and above results. We hope that this study could stir up our interest in the advancement of imaging diagnoses and minimally invasive surgical treatment of pancreas.

What comprises the plate-like structure between the pancreatic head and the celiac trunk and superior mesenteric artery? A proposal for the term "P-A ligament" based on anatomical findings.

A plate-like structure is located posterior to the portal vein system, between the pancreatic head and roots and/or branches of two major arteries of the aorta: the celiac trunk and superior mesenteric artery. We aimed to clarify the distribution and components of this plate-like structure. Macroscopic examination of the upper abdomen and histological examination of the plate-like structure were performed on 26 cadavers. The plate-like structure is connected to major arteries (aorta, celiac trunk, superior mesenteric artery) and the pancreatic head; it contains abundant fibrous bundles comprising nerves, vessels, collagen fibers, and adipose tissue. Furthermore, it consists of three partly overlapping fibrous components: rich fibrous bundles (superior mesenteric artery plexus) fused to the uncinate process of the pancreas; fibrous bundles arising from the right celiac ganglion and celiac trunk that spread radially to the dorsal side of the pancreatic head and superior mesenteric artery plexus; and fibrous bundles, accompanied by the inferior pancreaticoduodenal artery, entering the pancreatic head. The plate-like structure is the pancreas-major arteries (aorta, celiac trunk, superior mesenteric artery) ligament (P-A ligament). The term "P-A ligament" may be clinically useful and can facilitate comprehensive understanding of the anatomy surrounding the pancreatic head and provide an anatomical basis for further pancreatic surgery studies.

Distance measurements and origin levels of the coeliac trunk, superior mesenteric artery, and inferior mesenteric artery by multiple-detector computed tomography angiography.

The aim of this study is to determine vertebral levels of the coeliac trunk, the superior mesenteric artery, and the inferior mesenteric artery originated from the abdominal aorta and to calculate the distance measurements between these arteries and between these arteries and the aortic bifurcation by multidetector computed tomography angiography technique. It was determined that the nine different vertebral levels of the coeliac trunk, the nine different vertebral levels of the superior mesenteric artery, and the eleven different vertebral levels of the inferior mesenteric artery. The distance measurements between the coeliac trunk and the superior mesenteric artery, the inferior mesenteric artery, the aortic bifurcation were found significant between female and male. In this study, it was determined more different levels than the levels described in classical anatomy. The preoperative information of these morphological variations can contribute to the reduction of surgical time and perioperative vascular complications especially for anterior lumbar interbody fusion and defining the location of the primary lymphatic drainage site for gastrointestinal malignancies.

An anatomical review of various superior mesenteric artery-first approaches during pancreatoduodenectomy for pancreatic cancer.

When pancreatic head cancer invades the superior mesenteric artery (SMA), attempts at curative resection are aborted. Preoperative imaging diagnostics to determine the surgical curability have yet to surpass the intraoperative information acquired via inspection, palpation, and trial dissection. Pancreatoduodenectomy (PD) is a standard measure for treating periampullary cancers. In conventional PD, SMA invasion is usually identified by dissecting the retroportal lamina, which connects the uncinate process and SMA nerve plexus after dividing the neck of the pancreas. During PD for pancreatic head cancer, this retroperitoneal margin frequently vitiates surgical curability. SMA-first approaches during PD are methods where the SMA is dissected first by severing the posterior pancreatic capsule to assess the SMA involvement of pancreatic cancer early in the operation. The first report of such an approach prompted subsequent reports of various maneuvers that are now known collectively as "artery-first" approaches. We herein review those approaches by classifying them according to (1) the side of the mesocolon from where the SMA approach occurs (supracolic or infracolic) and (2) the direction of access (right or left and anterior or posterior). The steps of the reported PD procedures are numbered according to a timeline and summarized using anatomical division of the SMA.

ANATOMICAL VARIATIONS OF THE SUPERIOR MESENTERIC ARTERY AND ITS CLINICAL AND SURGICAL IMPLICATIONS IN HUMANS.

INTRODUCTION: Superior mesenteric artery (SMA) usually arises from the abdominal aorta, just below the celiac trunk and it supplies the midgut-derived embryonic structures. Anatomical variations in this vessel contribute to problems in the formation and/or absorption of this part of the intestine and its absence has been recognized as the cause of congenital duodenojejunal atresia. OBJECTIVE: To analyze SMA anatomical variations in humans and the possible associated clinical and surgical implications. METHODS: This is a systematic review of papers indexed in PubMed, SciELO, Springerlink, Science Direct, Lilacs, and Latindex databases. The search was performed by two independent reviewers between September and December 2018. Original studies involving SMA variations in humans were included. SMA presence/absence, level, place of origin and its terminal branches were considered. RESULTS: At the end of the search, 18 studies were selected, characterized as for the sample, method to evaluate the anatomical structure and main results. The most common type of variation was when SMA originated from the right hepatic artery (6.13%). Two studies (11.11%) evidenced the inferior mesenteric artery originating from the SMA, whereas other two (11.11%) found the SMA sharing the same origin of the celiac trunk. CONCLUSION: SMA variations are not uncommon findings and their reports evidenced through the scientific literature demonstrate a great role for the development of important clinical conditions, making knowledge about this subject relevant to surgeons and professionals working in this area.

Safe exposure of the left renal vein during laparoscopic distal pancreatectomy for pancreatic ductal adenocarcinoma: anatomical variations and pitfalls.

PURPOSE: The left renal vein is technically difficult to expose during laparoscopic distal pancreatectomy for pancreatic ductal adenocarcinoma despite being an important landmark for posterior dissection. We hereby propose a novel technique to safely expose the left renal vein while avoiding the associated anatomical pitfalls. METHODS: The anatomy of the left renal artery and vein was analyzed using multidetector computed tomography. We initially exposed the left renal vein on the left posterior side of the superior mesenteric artery followed by exposure toward the left kidney. We retrospectively examined the perioperative results of this technique in 33 patients who underwent laparoscopic distal pancreatectomy. RESULTS: 15.7% of the patients had an accessory left renal artery coursing cranial to the vein. In 43.1%, the left renal arterial branch ventrally traversed the vein at the renal hilum, thereby posing a risk for arterial injury. The location of the left renal vein varies cranial (17.6%) or caudal (82.4%) to the pancreas. The left renal vein was exposed without any vascular injury using this technique. The median operative time was 259 min, blood loss was 18 mL, and R0 resection rate was 97.0%. CONCLUSIONS: The initial exposure of the left renal vein should, therefore, be on the left posterior side of the superior mesenteric artery.

Replaced right and common hepatic arteries with lienogastric trunk: a rare variant of celiaco-mesenteric anatomy.

We report a rare variant in mesenteric arterial anatomy: replacement of the right hepatic and common hepatic arteries to the SMA in a patient treated for hepatocellular carcinoma. The potential clinical implications of this unusual variation of celiaco-mesenteric anatomy will be discussed.

Hepatic arterial system anomalies encountered during pancreaticoduodenectomy - our experience.

We present our experience of incidence and management of aberrant hepatic arterial anatomy encountered during pancreaticoduodenectomy (PD). Patients undergoing PD between December 2014 and November 2016 at the Shaukat Khanum Memorial Cancer Hospital, Lahore were included in this short report. Preoperative imaging and operative findings of these patients were reviewed to evaluate the hepatic arterial anatomy and classified according to Hiatt classification. Sixty-four PD were performed with aberrant arterial anatomy identified in 24 (37.5%) of the cases. Most common anomaly was replaced right hepatic artery (rRHA) arising from the superior mesenteric artery seen in seven (11%) of the patients. Aberrant vessels were recognised and preserved in 23 cases. In one patient, the rRHA was coursing through the pancreatic parenchyma needing resection and reconstruction with uneventful postoperative recovery. Hepatic arterial anomalies are common and it is possible to preserve these vessels with careful surgical dissection using artery first technique.

Morphogenesis of the ventral pancreas anlagen is influenced by the SMA branching pattern.

Developmentally, the uncinate process of the pancreas is derived from the ventral pancreatic anlagen, supplied by the superior mesenteric artery (SMA), and contains pancreatic polypeptide (PP)-rich islets of Langerhans. In contrast, the other parts of the pancreas originate from the dorsal anlagen supplied by the celiac system and contain PP-poor islets. This study was performed to investigate whether morphogenesis of the ventral pancreas anlagen is associated with the pattern of SMA branching. SMA branches to the pancreatic body were dissected in 44 cadavers. The cadavers were divided into two groups: the SMA group in which the SMA gave off branches to the pancreatic body and the General group in which it did not. In the SMA group, the ratio of the diameter of the SMA branch supplying the pancreatic body (SMA branch) to that of the SMA itself was calculated. After dissection was completed, tissues were collected from all pancreatic specimens for HE staining and for immunohistochemistry with PP and insulin antibodies. There were 25 cadavers in the General group and 19 in the SMA group. In 10/19 cadavers from the SMA group, PP-rich islets were confirmed in the pancreatic body. The SMA branch diameter ratio was significantly smaller in the SMA group cadavers with PP-poor islets (n = 9) than in cadavers with PP-rich islets (n = 10) (P < 0.001). These findings suggest a relation between the SMA branching pattern and the distribution of PP cells.