The meandering mesenteric artery: a historic review and surgical implications

Inferior Mesenteric Artery Ligation Level in Rectal Cancer Surgery beyond Conventions: A Review

Within the intricate field of rectal cancer surgery, the contentious debate over the optimal level of ligation of the inferior mesenteric artery (IMA) persists as an ongoing discussion, influencing surgical approaches and patient outcomes. This narrative review incorporates historical perspectives, technical considerations, and functional as well as oncological outcomes, addressing key questions related to anastomotic leakage risks, genitourinary function, and oncological concerns, providing a more critical understanding of the well-known inconclusive evidence. Beyond the dichotomy of high versus low tie, it navigates the complexities of colorectal cancer surgery with a fresh perspective, posing a transformative question: "Is low tie ligation truly reproducible?" Considering a multidimensional approach that enhances patient outcomes by integrating the surgeon, patient, technique, and technology, instead of a rigid and categorical statement, we argued that a balanced response to this challenging question may require compromise.

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.

Collateral circulation develops in stenosis of the celiac trunk and superior mesenteric artery

PURPOSE

Mesenteric circulation is provided by the celiac trunk (CT), superior mesenteric artery (SMA), and inferior mesenteric artery (IMA). The collateral circulation between CT and SMA and between SMA and IMA plays a protective role against intestinal ischemia in case of narrowing or occlusion of the mesenteric vessels. In our study, it is aimed to determine the CT and SMA stenosis rates in patients with CT and SMA stenosis from angiography images, the occurrence of the collateral variations, and the frequency of these variations.

METHODS

A total of 408 non-selective or selective CT and SMA angiographic images were taken of 215 patients (130 males, 85 females) who were admitted to Akdeniz University Hospital with symptoms of chronic mesenteric ischemia (CMI) were included. The angiography images were analyzed in regards to CT and SMA stenosis rates, and the collateral variations between mesenteric vessels.

RESULTS

Stenosis of CT was observed in 14 patients, whereas the stenosis of the SMA was observed in 12 patients. The most common collateral vessel in these patients was the gastroduodenal artery. Both stenoses of CT and SMA were found in 9 patients. The Riolan arch was the most common type of collateral vessel in these patients.

CONCLUSION

It was observed that mesenteric circulation was mainly provided by gastroduodenal artery in patients with isolated CT or SMA stenosis or occlusion while in patients with stenosis or occlusion of both CT and SMA, mesenteric circulation was mainly provided by the Riolan arch. A significant increase was observed in the prominence of collateral vessels in patients with stenosis of more than 70%.

Correlation of Riolan's arch diameter to treatment choice in patients with isolated superior mesenteric artery dissection

OBJECTIVE

To investigate the diameter changes of Riolan's arch in patients with isolated superior mesenteric artery dissection (ISMAD) and to evaluate the implication for treatment selection.

METHODS

Ninety-five patients with CT angiography (CTA) confirmed ISMAD were retrospectively included, and another 95 cases with no positive findings on abdominal CTA were included as controls. According to the treatment methods, the patients were subsequently divided into conservative treatment (n = 68) or invasive treatment (n = 27) subgroups. According to the initial CTA images, the prevalence of Riolan's arch as well as its diameter (D_R) were determined in each subject, and compared between ISMAD and control cases, as well as between patients with different treatments. In patients with ISMAD, dissections were classified according to the Li classification.

RESULTS

Riolan's arch prevalence and D_R were significantly elevated in the ISMAD group compared with the control group (83.16% vs. 35.79%, P < 0.001; 2.63 ± 0.56 mm vs. 2.12 ± 0.39 mm, P < 0.001). Patients with invasive treatment had significantly higher baseline D_R (2.93 ± 0.57 mm vs. 1.89 ± 1.14 mm, P < 0.001), and higher proportion of high-risk dissection (P < 0.001) than those administered conservative treatment. Binary logistic regression revealed D_R (OR = 2.771, 95% CI 1.157-6.638, P = 0.022) and Li classification (OR = 0.107, 95% CI 0.019-0.586, P = 0.010) were independent risk factors for treatment selection. With cutoff of 2.635 mm, the area under the curve, sensitivity, and specificity were 0.805, 0.778 and 0.794, respectively.

CONCLUSION

Dilation of Riolan's arch is common in patients with ISMAD, and Riolan's arch diameter could be a convenient indicator of disease severity and inform subsequent treatment.

3D mesenteric angiogram-based assessment of Arc of Riolan crossing the inferior mesenteric vein: important considerations in high ligation during splenic flexure takedown in anterior resection

Background

Recent studies have described the finding of the Arc of Riolan (AoR) crossing the inferior mesenteric vein (IMV) seen during high ligation of IMV while performing minimally invasive colectomies. However, the AoR usually has a medial course, and this variant AoR anatomic course and the clinical importance of its preservation during splenic flexure takedown in anterior resection remains controversial.

Methods

After institutional approval (QA-5775), radiological identification of and mapping of the vessel horizontally crossing the IMV under the pancreas, when present, was performed at a single institution (Westmead Hospital, New South Wales, Australia). One hundred consecutive computed tomographic (CT) mesenteric angiograms conducted in 2018 were reviewed retrospectively to determine the presence of a vessel horizontally crossing the IMV. 3D reconstructions were used to map out its course to understand its origin and full course. Baseline characteristics, including demographic and comorbidity data, were obtained from the medical record.

Results

On 3D mesenteric angiogram reconstructions, a vessel crossing anterior to the IMV was present in 11 of 98 cases (11.2%). Two cases were excluded as the presence of this vessel was indeterminate. Eight of 11 patients (72.7%) were male, and the mean age was 49.3 years (range: 21–80 years). There was no statistically significant difference in age and comorbidities between the groups. Importantly, in all 11 cases, there was an arterial vessel crossing the IMV originating from the SMA and communicating with the IMA or a branch of the IMA, proving definitively that this vessel was by definition the AoR.

Conclusion

This 3D mesenteric angiogram mapping study has shown definitively that the vessel horizontally crossing anterior to the IMV and inferior to the pancreas is an arterial vessel from the SMA to IMA, and by definition the Arc of Riolan. When present, identification and preservation of this collateral arterial vessel during splenic flexure takedown in anterior resection may be important in reducing the risk of post-operative bowel ischaemia.

A US Rectal Cancer Consortium Study of Inferior Mesenteric Artery Versus Superior Rectal Artery Ligation: How High Do We Need to Go?

BACKGROUND

The optimal level of pedicle ligation during proctectomy for rectal cancer, either at the origin of the inferior mesenteric artery or the superior rectal artery, is still debated.

OBJECTIVE

The objective was to determine whether superior rectal artery ligation portends equivalent technical or oncologic outcomes.

DESIGN

This was a retrospective analysis of a rectal cancer database (2007-2017).

SETTINGS

The study was conducted at 6 tertiary referral centers in the United States (Emory University, University of Michigan, University of Pittsburgh Medical Center, The Ohio State University Wexner Medical Center, Vanderbilt University Medical Center, and Washington University School of Medicine in St. Louis).

PATIENTS

Patients with primary, nonmetastatic rectal cancer who underwent low anterior resection or abdominoperineal resection were included.

MAIN OUTCOME MEASURES

Anastomotic leak, lymph node harvest, locoregional recurrence-free survival, recurrence-free survival, and overall survival were measured.

RESULTS

Of 877 patients, 86% (n = 755) received an inferior mesenteric artery ligation, whereas 14% (n = 122) received a superior rectal artery ligation. A total of 12%, 33%, 24%, and 31% were pathologic stage 0, I, II, and III. Median follow-up was 31 months. Superior rectal artery ligation was associated with a similar anastomotic leak rate compared with inferior mesenteric artery ligation (9% vs 8%; p = 1.0). The median number of lymph nodes removed was identical (15 vs 15; p = 0.38). On multivariable analysis accounting for relevant clinicopathologic factors, superior rectal artery ligation was not associated with increased anastomotic leak rate, worse lymph node harvest, or worse locoregional recurrence-free survival, recurrence-free survival, or overall survival (all p values >0.1).

LIMITATIONS

This was a retrospective design.

CONCLUSIONS

Compared with inferior mesenteric artery ligation, superior rectal artery ligation is not associated with either worse technical or oncologic outcomes. Given the potential risks of inadequate blood flow to the proximal limb of the anastomosis and autonomic nerve injury, we advocate for increased use of superior rectal artery ligation. See Video Abstract at http://links.lww.com/DCR/B646.

ESTUDIO DEL CONSORCIO DE CNCER DE RECTO DE ESTADOS UNIDOS DE LIGADURA BAJA DE LA ARTERIA MESENTRICA INFERIOR CONTRA LIGADURA ALTA DE LA ARTERIA MESENTRICA INFERIOR QU TAN ALTO DEBEMOS EXTENDERNOS

ANTECEDENTES:el nivel óptimo de la ligadura del pedículo en la proctectomía para el cáncer de recto, ya sea en el origen de la arteria mesentérica inferior o en la arteria rectal superior aún no esta definido.OBJETIVO:El objetivo era determinar si la ligadura de la arteria rectal superior pronostica resultados técnicos u oncológicos similares.DISEÑO:Análisis retrospectivo de una base de datos de cáncer de recto (2007-2017).ESCENARIO:el estudio se realizó en seis centros de referencia de tercer nivel en los Estados Unidos (Universidad de Emory, Universidad de Michigan, Centro médico de la Universidad de Pittsburgh, Centro médico Wexner de la Universidad Estatal de Ohio, Centro médico de la Universidad de Vanderbilt y Escuela de Medicina de la Universidad de Washington en St. Louis).PACIENTES:Se incluyeron pacientes con cáncer de recto primario no metastásico que se sometieron a resección anterior baja o resección abdominoperineal.PRINCIPALES VARIABLES ANALIZADAS:Se midió la fuga anastomótica, los ganglios linfáticos recuperados, la sobrevida sin recidiva locorregional, la sobrevida sin recidiva y la sobrevida global.RESULTADOS:De 877 pacientes, en el 86% (n = 755) se realizó una ligadura de la arteria mesentérica inferior, y en el 14% (n = 122) se realizó una ligadura de la arteria rectal superior. El 12%, 33%, 24% y 31% estaban en estadio patológico 0, I, II y III respectivamente. La mediana de seguimiento fue de 31 meses. La ligadura de la arteria rectal superior se asoció con una tasa de fuga anastomótica similar a la ligadura de la arteria mesentérica inferior (9 vs 8%, p = 1,0). La mediana del número de ganglios linfáticos extirpados fue idéntica (15 contra 15, p = 0,38). En el análisis multivariado que tiene en cuenta los factores clínico-patológicos relevantes, la ligadura de la arteria rectal superior no se asoció con una mayor tasa de fuga anastomótica, una peor cosecha de ganglios linfáticos o una peor sobrevida libre de recurrencia locorregional, sobrevida libre de recurrencia o sobrevida global (todos p> 0,1).LIMITACIONES:Diseño retrospectivo.CONCLUSIONES:En comparación con la ligadura de la arteria mesentérica inferior, la ligadura de la arteria rectal superior no se asocia a peores resultados técnicos ni oncológicos. Debido a los riesgos potenciales de un flujo sanguíneo inadecuado del muñon proximal de la anastomosis y la lesión de los nervios autonómicos, proponemos una mayor realización de la ligadura de la arteria rectal superior. Consulte Video Resumen en http://links.lww.com/DCR/B646.

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.

Redefining the collateral system between the superior mesenteric artery and inferior mesenteric artery: a novel classification

AIM

The aim of this study was to evaluate the arterial collateral vasculature between the superior mesenteric artery and the inferior mesenteric artery (IMA) from a surgical perspective.

METHOD

A total of 107 fresh adult cadavers (94 male) were studied with emphasis on the vascular anatomy of the left colon. Dissections were carried out mimicking the anterior resection technique. The vasculature of the left mesocolon and the collaterals between the superior mesenteric artery and the IMA with respect to their relationship to the inferior mesenteric vein (IMV) were assessed and classified. Collaterals were classified into three different groups: marginal anastomoses (via the marginal = pericolic artery), intermediate mesocolic anastomoses (parallel to the marginal artery but neither adjacent to the IMV nor close to the duodenum) and central mesocolic anastomoses (next to the IMV at the level of the duodenojejunal junction and the lower border of the pancreas).

RESULTS

All patients had a marginal anastomosis. However, the marginal anastomosis, as the only anastomosis between the superior and inferior mesenteric arteries at the splenic flexure, was observed in 41 cases (38%). In addition to the marginal artery, intermediate mesocolic anastomoses were found in 49 (46%) and a central mesocolic anastomosis was observed in 17 (16%) of the 107 cases in the splenic flexure mesocolon. It is in this latter variant that collateral vessels can be compromised during ligation/transection of the IMV.

CONCLUSION

This new classification can contribute to a precise mesocolic dissection technique and splenic flexure mobilization and help prevent ischaemic damage to the descending colon.

The importance of the Moskowitz artery as a lesser-known collateral pathway in the medial laparoscopic approach to splenic flexure mobilisation and its evaluation with preoperative computed tomography

INTRODUCTION

The collateral pathways between the superior mesenteric artery (SMA) and inferior mesenteric artery (IMA) play an important role in colonic surgery. The most well-known are the Drummond marginal artery and Riolan's arch. The Moskowitz artery, also known as the meandering mesenteric artery, is a lesser-known collateral pathway and represents another link between SMA and IMA. The Moskowitz artery runs along the colonic mesentery floor and represents the link between the proximal segment of the middle colic artery and the ascending branch of the left colic artery.

AIM

To comprehend the presence and importance of the Moskowitz artery (meandering mesenteric artery) in preoperative patients by using computed tomography (CT) studies.

MATERIAL AND METHODS

We retrospectively reviewed all abdominal CT images performed using intravenous contrast for any reason at the Radiology Department of Yeditepe University Hospital between April 2015 and September 2018. Patients older than 18 years with intravenous contrast (arterial and venous phases with a cross-section thickness of 0.625 mm), who underwent abdominal CT scan, and patients without any abdominal surgery were included in the study. As a result of the screening, 109 CT scans with eligibility criteria were included in this study.

RESULTS

There were 109 cases in this study; 50 (45.9%) of them were male and 59 (54.1%) were female. Moskowitz artery was found in 18 (16.5%) cases; 8 were males and 10 were females. Riolan's arch was present in 30 cases, of whom 15 were male and 15 were female. In our study Moskowitz artery and Riolan's arch were monitored as separate vascular structures, and in all cases with Moskowitz artery, Riolan's arch was also present. There was a statistically significant difference (p < 0.05) between the combined MCA emerging type and the presence of MA, and 12 cases with combined branch and 6 cases with single branch had Moskowitz artery. There was a statistically significant difference (p < 0.05) between LCA types and the presence of MA, and the Moskowitz artery was the most common seen at type 1 LCA.

CONCLUSIONS

Knowledge of the relationship between Riolan's arch and the Moskowitz artery is valuable, and preoperative evaluation of this artery may be beneficial in the presence of Riolan's arch. In addition, preoperative radiological evaluation and its importance are prominent in minimising intraoperative bleeding during splenic flexure mobilisation with a medial laparoscopic approach and reducing the risk of colorectal anastomosis leakage.

The effect of different inferior mesenteric artery ligation levels and different lymph node dissection areas on the short- and long-term outcomes of rectal cancer

Background

Surgery is the most effective treatment for rectal cancer patients, but its key steps, including selection of the level of inferior mesenteric artery ligation and removal of 253 lymph nodes, are still inconclusive. This study aimed to analyze the effects of different surgical methods, including levels of ligation (low vs. high) and lymph node dissection areas (D2 vs. D3) on the short-term and long-term outcomes.

Methods

Between March 2014 and August 2018, 253 rectal cancer patients were retrospectively analyzed; 113 patients underwent low ligation D2 lymph node dissection (LLD2), 75 patients underwent low ligation D3 lymph node dissection (LLD3), and 65 patients underwent high ligation (HL). We compared the short-term and long-term outcomes among the different groups.

Results

There were no significant differences among the groups in terms of the intraoperative variables, including operative time, blood transfusion, and conversion from laparoscopic to open surgery. The median blood loss was significantly lower in LLD3 (50 mL) than in LLD2 (100 mL) and HL (100 mL), but it was not significantly different between LLD2 and HL. There were no significant differences among the LLD2, LLD3, and HL groups in the incidence of postoperative complications (9.7% vs. 12.0% vs. 10.8%, respectively) and hospital stay (14 vs. 15 vs. 14, respectively). The anastomotic leakage Clavien-Dindo grade was significantly lower with LLD2 and LLD3 than with HL, but it was the same between LLD2 and LLD3. The total number of lymph nodes harvested in the LLD3 group (n=14) was higher than that in the LLD2 group (n=12), but it was not significantly different than that in the HL group (n=13). There were no significant differences among the groups in terms of 3-year overall survival rate and disease-free survival rate.

Conclusions

Low ligation was similar to HL in terms of major intraoperative and postoperative parameters, but it can reduce the severity of anastomotic leakage to a certain extent. D3 lymph node dissection can increase the total number of lymph nodes harvested, but it did not improve long-term prognosis.

A prospective study of real-time identification of line of transection in robotic colorectal cancer surgery by ICG

Colorectal cancer is the second most common cancer in women and the third most common cancer in men in the world. Surgical resection is the gold standard treatment and minimally invasive surgery remains the standard of care. Anastomotic leakage is one of the most feared postoperative complications in colorectal surgery. Although several factors have been identified as possible causes of anastomotic leakage (i.e., surgical techniques, patient risk factors, suture material or devices), the complete pathogenesis is still unclear. The reported leak rate ranges from 1 to 30% and increases as the anastomosis is more distal. To date the most widely used methods to assess tissue perfusion includes the surgeon intraoperative visual judgement based on the colour; bleeding edges of resected margins; pulsation and temperature, thereby resulting in either excess or insufficient colonic resection. Earlier studies in colorectal surgery have suggested that assessment of tissue perfusion by the clinical judgment of the operating surgeon underestimated the risk of anastomotic leakage. Indocyanine green (ICG) is a intravenous dye which has shown promise in identifying the bowel vascularity real time. Earlier studies on colorectal cancer have shown that ICG based detection of bowel vascularity is technically possible and has reduced the anastomotic leak rates in 16.7% of patients. We conducted a prospective study on patients with ICG guided bowel perfusion during robotic colorectal cancer surgery. The method is technically easy, reproducible and safe. This technique has changed the intraoperative decision in 88% of patients. Larger studies are needed before this can become the standard of care.

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

AIM

Recently, the accessory middle colic artery (AMCA) has been recognized as the vessel that supplies blood to the splenic flexure. However, the positional relationship between the AMCA and inferior mesenteric vein (IMV) has not been evaluated. Herein, we aimed to evaluate the anatomy of the AMCA and the splenic flexure vein (SFV).

METHOD

Two hundred and five patients with colorectal cancer who underwent enhanced CT preoperatively were enrolled in the present study. The locations of the AMCA and IMV were evaluated, focusing on the positional relationship between the vessels and pancreas - below the pancreas or to the dorsal side of the pancreas.

RESULTS

The AMCA was observed in 74 (36.1%) patients whereas the SFV was found in 177 (86.3%) patients. The left colic artery (LCA) was the major artery accompanying the SFV in 87 (42.4%) of patients. The AMCA accompanied the SFV in 65 (32.7%) patients. In 15 (7.8%) patients, no artery accompanied the SFV. The origin of the AMCA was located on the dorsal side of the pancreas in 15 (20.3%) of these 74 patients. Similarly, the destination of the IMV was located on the dorsal side of the pancreas in 65 (31.7%) of patients.

CONCLUSION

The SFV was observed in most patients, and the LCA or AMCA was the common accompanying artery. In some patients these vessels were located on the dorsal side of the pancreas and not below it. Preoperative evaluation of this anatomy may be beneficial for lymph node dissection during left-sided hemicolectomy.

Revascularisation of iatrogenic superior mesenteric artery injury by end to end anastomosis during robot assisted nephrectomy

INTRODUCTION

Superior mesenteric artery (SMA) injury is very peculiar to left sided renal surgery. Although it is rare only, most of it is unreported. We report a case of SMA injury during robot assisted laparoscopic nephrectomy, which was managed successfully by end to end anastomosis.

CASE PRESENTATION

A 19-year-old male patient was undergoing robot assisted laparoscopic simple nephrectomy for pyelonephritic kidney. Because of dense adhesion, SMA was inadvertently clipped and cut. It was recognised intraoperatively and an end to end anastomosis was done by laparotomy.

DISCUSSION

SMA injury is rarely encountered in surgical practice. Most of it occurs following trauma. Iatrogenic SMA injury occurs in case of distorted local anatomy either due to adhesion or bulky tumor in left renal fossa and vicinity.

CONCLUSION

One should be cautious about proximity of SMA and its possible injury during left nephrectomy and it should be repaired as soon as possible.

Abdominal aortic aneurysm with occlusion of three primary mesenteric vessels treated by surgery with perfusion of the left iliac artery†

A 64-year-old woman who underwent thoraco-abdominal aortic replacement for a Crawford type II aneurysm 11 years ago was referred to our hospital because of a residual juxtarenal abdominal aortic aneurysm. The coeliac, superior mesenteric and inferior mesenteric arteries were occluded. Collateral vessels from the left internal iliac artery to these 3 mesenteric arteries had developed. We performed open aneurysm repair using an extracorporeal circuit to maintain collateral flow to these mesenteric arteries.

Successful conservative treatment of acute traumatic occlusions of the celiac artery and superior mesenteric artery: A case report emphasizing the importance of the visceral collateral circulations

RATIONALE

Blunt injury of major visceral arteries such as celiac artery (CA) and superior mesenteric artery (SMA) are very rare but fatal, therefore, these injuries are challenging to trauma surgeons. The patient with occlusion of CA or SMA is theoretically viable by visceral collateral circulation. However, there are very rare cases in clinics. To date, there have been few reports of both CA and SMA occlusions after blunt trauma. Herein we describe our successful conservative treatment of patients with both CA and SMA occlusions.

PATIENT CONCERNS

Fifteen-year-old girl suffering from schizophrenia was transferred to our hospital after a fall from 3-floor-height with a purpose of suicide.

DIAGNOSES

An abdominal computed tomography (CT) scan with contrast enhancement showed proximal CA and proximal SMA occlusions with surrounding retroperitoneal hematoma, however, distal parts of occlusion were supplied by the collateral vessels (enlarged marginal artery of left colon from inferior mesenteric artery and pancreaticoduodenal arcade).

INTERVENTIONS

She was treated by only supportive care without anticoagulant due to retroperitoneal hematoma.

OUTCOMES

The patient was discharged 25 days after admission without complications.

LESSONS

We think that our patient could survive because her vascular status was healthy and collateral circulations were plenty according to the young age. We believe that this case can provide a basis for ligation in these forbidding and handless major visceral arterial injuries such as CA or SMA.

Arc of Riolan-Preserving Splenic Flexure Takedown During Anterior Resection: Potentially Critical to Prevent Acute Anastomotic Ischemia

INTRODUCTION

The Arc of Riolan is a strategic vessel that provides collateral mesenteric circulation in 10% of individuals. The importance of identifying and preserving the arc of Riolan in reducing the risk of ischemia to the proximal anastomotic segment after high ligation anterior resection was evaluated.

TECHNIQUE

The arc of Riolan is a vessel that crosses anterior to the inferior mesenteric vein horizontally below the level of the pancreas. A retrospective review of all recorded videos of laparoscopic and robotic low and ultra-low anterior resections was performed in September to December 2012 and prospective evaluation in April to July 2013. The main outcome measures were arc of Riolan identification and preservation, and this was correlated with postoperative transmural colonic ischemia requiring surgical reintervention. From July 2013 onward, we routinely performed arc of Riolan-sparing anterior resections.

RESULTS

Arc of Riolan was observed in 17.8% of cases. Between 2006 and 2012, before routinely looking for and preserving the arc of Riolan, our rate of acute colonic transmural ischemia requiring an emergency Hartmann procedure after anterior resection was 0.8% (6/723). Between 2012 and 2016, after we started performing arc of Riolan-sparing splenic flexure takedown, there were no cases of acute colonic transmural ischemia requiring surgical reintervention (0/576) after anterior resection.

CONCLUSIONS

Recognizing and preserving the arc of Riolan, if visualized, during high inferior mesenteric vein ligation and splenic flexure takedown may be an important step in reducing the risk of acute colonic ischemia postanterior resection. See Video at http://links.lww.com/DCR/A535.

Reversal of Acute Mesenteric Ischemia by Salvation of the Meandering Mesenteric Artery with Stenting of the Left Internal Iliac Artery

The presence of the meandering mesenteric artery, which is a nonconstant tortuous arterial component unifying the peripheral intestinal circulation, is evidence of chronic occlusive disease of the main intestinal arteries. This collateral intestinal arterial pathway, when present, must be preserved in any abdominal intervention, as it is often the only remaining arterial supply of the intestine; its ligation can be accompanied by intestinal ischemia. We present herein, the case of a 42-year-old man, heavy smoker, who had chronic mesenteric ischemia without particular clinical manifestations till the hospitalization for acute myocardial infarction for which he underwent balloon angioplasty and stenting of the left circumflex coronary artery. Three days later, he experienced acute-on-chronic intestinal ischemia with crescendo clinical manifestations; intra-arterial angiography revealed the presence of a meandering mesenteric artery in a milieu of celiac, superior and inferior mesenteric, and right internal iliac artery occlusion accompanied by a tight stenosis of the left internal iliac artery. Successful stenting of the orifice of the left internal iliac artery was followed by a well-defined dilatation of the meandering artery, revascularization of the peripheral branches of the inferior-through the superior hemorrhoidal artery-and superior mesenteric arteries and complete resolution of the acute mesenteric ischemia. Thus, time was gained for the patient in order to have, if needed, a future elective open revascularization of the mesenteric artery, when the perioperative risk of mortality from the recent myocardial infarction and the coronary angioplasty and stenting will be minimal.

Importance of the Moskowitz artery in the laparoscopic medial approach to splenic flexure mobilization: a cadaveric study

BACKGROUND

The medial approach in laparoscopic splenic flexure mobilization is based on the entrance to the lesser sac just above the ventral edge of the pancreas (VEOP). The artery of Moskowitz runs through the base of the mesocolon, just above the VEOP. The aim of this study was to assess the incidence of the artery of Moskowitz, its route and its distance from the VEOP.

METHODS

We performed a cadaveric study on 27 human cadavers. The vascular arcades of the splenic flexure were dissected, the number of vascular arches, and the origin and localization of its terminal anastomosis were recorded. The splenic flexure avascular space (SFAS) was defined as the avascular zone in the mesocolon delimited by the VEOP, middle colic artery, ascending branch of the left colic artery and the vascular arch of the splenic flexure nearest to the VEOP and was quantified as the distance between the VEOP and the most proximal arch RESULTS: The artery of Drummond was identified in 100% of the cadavers. In 5 of 27 (18%) Riolan's arch was present, and in 3 of 27 (11%) the Moskowitz artery was found. The mean distance from the VEOP to the artery of Moskowitz was 0.3 cm (SD 0.04). This vascular arch travelled from the origin of the middle colic artery to the distal third of the ascending branch of the left colic artery. The SFAS was greater (p = 0.001) in cadavers that only presented the artery of Drummond (mean 6.8 cm; SD 1.25) than in those with Riolan's arch (mean 4.5 cm; SD 0.5) CONCLUSIONS: In the medial approach for laparoscopic mobilization of the splenic flexure, when only one of the arches is present, the avascular area is an extensive and secure territory. If the artery of Moskowitz is present, the area is nonexistent and this would contraindicate the approach due to risk of iatrogenic bleeding. A radiological preoperatory study could be essential for accurate and safe surgery in this area.

Dacron graft aneurysm with dissection

Dacron grafts have been used as a conduit for large caliber arteries for many years successfully. However, these grafts can undergo complications such as aneurysm formation, rupture, and failure. Evaluation of these complications are of paramount importance because of its tendency to rupture and cause death. Imaging plays an important role in identifying and monitoring of these complications, and also provides a road map to the vascular surgeons for early intervention and revascularization.

Reconstruction after esophagectomy for esophageal cancer patients with a history of gastrectomy

Pedicled jejunal flap and colon graft interposition are choices for esophageal reconstruction in patients with a history of gastrectomy or those who have undergone synchronous esophagogastrectomy. However, the optimal conduit in this situation is still being debated. We reviewed the literature concerning esophageal reconstruction using a conduit other than the stomach. Approximately 10 % of esophagectomized patients undergo esophageal reconstruction using pedicled jejunum or colon interposition in Japan. The jejunal graft and colon graft are selected evenly, although the percentage of jejunal graft use is gradually increasing. Microvascular supercharge was performed in most of the reports of pedicled jejunal graft reconstruction, whereas vascular enhancement was not popularly used in the reports of colon graft interposition. Although the incidences of graft loss and anastomotic leakage were comparable between grafts, mortality rates seem to be higher in patients who undergo colon graft reconstruction than in those who undergo reconstruction with a jejunal graft. Prospective comparisons of short-term outcomes as well as long-term quality of life are needed to identify the best method of reconstruction.

Anatomic and radiologic review of chronic mesenteric ischemia and its treatment

Chronic mesenteric ischemia (CMI) is a vascular occlusive disease process that generally affects the elderly population. Clinical presentation occurs when two of the three mesenteric arteries are affected and includes non-specific abdominal pain and weight loss. The most common cause of CMI is atherosclerotic arterial occlusion. The aim of this review is to present the vascular anatomy of the mesenteric arterial circulation including the different collateral pathways. The imaging findings and the different treatment options with a brief review of the literature is presented.

Colectomy in patients with previous colectomy or occlusive vascular diseases: Pitfalls and precautions

Two principal branches from the aorta provide the colonic blood supply: the superior and inferior mesenteric arteries. There are numerous anatomical variations, which the surgeon must fully understand before embarking on any colonic surgery. A good knowledge of these variations is particularly important when the patient has already undergone colectomy or presents with occlusive vascular disease. The aim of this review is to summarize the standard anatomy and the main variations of the colonic blood supply as they apply to colorectal surgery in this setting.

Surgical Anatomy of the Gastrointestinal Tract and Its Vasculature in the Laboratory Rat

The aim of this study was to describe and illustrate the morphology of the stomach, liver, intestine, and their vasculature to support the planning of surgical therapeutic methods in abdominal cavity. On adult Wistar rats corrosion casts were prepared from the arterial system and Duracryl Dental and PUR SP were used as a casting medium and was performed macroscopic anatomical dissection of the stomach, liver, and intestine was performed. The rat stomach was a large, semilunar shaped sac with composite lining. On the stomach was very marked fundus, which formed a blind sac (saccus cecus). The rat liver was divided into six lobes, but without gall bladder. Intestine of the rat was simple, but cecum had a shape as a stomach. The following variations were observed in the origin of the cranial mesenteric artery. On the corrosion cast specimens we noticed the presence of the anastomosis between middle colic artery (a. colica media) and left colic artery (a. colica sinistra). We investigated the second anastomosis between middle colic artery and left colic artery. The results of this study reveal that the functional anatomical relationship between the rat stomach, liver and intestine is important for the development of surgical research in human and veterinary medicine.

Historical perspective: eponyms of vascular radiology

Eponyms are ubiquitous throughout the medical literature, especially the radiology lexicon. In particular, vascular radiology is replete with dozens of eponyms named after pathologic and anatomic features and various medical devices. Several disease processes are known exclusively by their eponyms or by both their eponyms and their descriptive names. Although some authors advocate abandoning eponyms in favor of more descriptive terms, the established history and common use of eponyms make it unlikely that they will disappear from the vocabulary. Radiologists should be familiar with both the eponymous and descriptive names of disease processes to ensure effective communication and prevent erroneous identification. Study of these eponyms provides information about these disease processes and other medical knowledge for use in daily practice. In addition, biographic information about the pertinent physicians can yield insights into the sometimes surprising origins of these eponyms. The authors provide biographic sketches of these physicians and discuss the clinical relevance of the anatomic features, malformations, and syndromes that bear their names.

Origin of the celiac and superior mesenteric arteries in a common trunk: description of a rare vessel variation of the celiacomesenteric trunk with a literature review

A variation artery was observed in a Japanese cadaver. The celiac and superior mesenteric arteries arose from a common trunk (also referred to as the celiacomesenteric trunk), but not from the abdominal aorta, respectively. From the common trunk, the common hepatic artery was distributed in the right part of the liver, and the left hepatic artery arose from the left gastric artery, which also arose from the common trunk. The left inferior phrenic artery arose from the common trunk, but the right inferior phrenic artery arose from the right middle suprarenal artery. This information regarding the branch pattern in this variation artery is useful for clinical examination and treatment.

A mixed-type intermesenteric trunk as a major contributor to the ascending, transverse, and descending colons: a case report

PURPOSE

We present a case in which a mixed-type intermesenteric trunk was the major arterial supply for the ascending, transverse, and descending colons.

METHODS

We dissected a cadaver of a man aged 74 years that was used for a routine abdominal dissection course of 2nd year medical students.

RESULTS

We observed that a mixed-type intermesenteric trunk supplied the majority of the colon, originating from the inferior mesenteric artery. The vessel was non-tortuous and had a counter clockwise course. It gave branches that supply the marginal artery at the splenic and hepatic flexures and at the transverse colon and finally it anastomosed with the ileocolic artery at the ileocecal junction. Through the intermesenteric trunk, the inferior mesenteric artery supplied the descending, transverse, and ascending colons with contributions from the sigmoidal and ileocolic arteries.

CONCLUSIONS

The intermesenteric trunk is an important central connection between the superior and inferior mesenteric arteries. It probably is an embryologic remnant that constituted a longitudinal anastomosis between both mesenteric arteries.

A rare case of aneurysm of arc of riolan artery and gastroduodenal artery

Arc of Riolan is a collateral channel that connects the proximal superior mesenteric artery (SMA) or its middle colic branch and the proximal inferior mesenteric artery or its left colic branch in case of stenosis of either of the arteries. A 65-year-old diabetic female presented with vague abdominal pain. Ultrasonography showed a large aneurysm within the abdomen in the left lumbar region. Computed tomography (CT) angiography done showed severe diffuse atherosclerotic calcification of the abdominal aorta with complete occlusion of the celiac trunk and mild stenosis of SMA origin. The arc of Riolan was seen between the middle colic artery and the ascending branch of the left colic artery, with a large saccular aneurysm in its mid section. No evidence of rupture or hematoma was visible. Another saccular aneurysm was also seen involving the gastro-duodenal and the pancreatico-duodenal collateral arcade. As far as we know, this is the first case of arc of Riolan artery aneurysm to be reported in English literature.

The relation between inferior mesenteric vein ligation and collateral vessels to splenic flexure: anatomical landmarks, technical precautions and clinical significance

PURPOSE

Our aim to assess clinical significance of the relation between inferior mesenteric vein ligation and collateral blood supply (meandering mesenteric artery) to the splenic flexure with elaboration more in anatomical landmarks and technical tips.

MATERIALS AND METHODS

We review the literature regarding the significance of the collateral vessels around inferior mesenteric vein (IMV) root and provide our prospective operative findings, anatomical landmarks and technical tips. We analyzed the incidence and pattern of anatomic variation of collateral vessels around the IMV.

RESULTS

A total of 30 consecutive patients have been prospectively observed in a period between June 25-2012 and September 7-2012. Nineteen males and eleven females with mean age of 63 years. Major colorectal procedures were included. There were three anatomical types proposed, based on the relation between IMV and the collateral vessel. Type A and B in which either the collateral vessel crosses or runs close to the IMV with incidence of 43.3% and 13.3%, respectively, whereas type C is present in 43.3%. There was no definitive relation between the artery and vein. No intra or postoperative ischemic events were reported.

CONCLUSION

During IMV ligation, inadvertent ligation of Arc of Riolan or meandering mesenteric artery around the IMV root "in type A&B" might result in compromised blood supply to the left colon, congestion, ischemia and different level of colitis or anastomotic dehiscence. Therefore, careful dissection and skeletonization at the IMV root "before ligation if necessary" is mandatory to preserve the collateral vessel for the watershed area and to avoid further injury.

Right colectomy with simultaneous vascular reconstruction for celiac and superior mesenteric arterial occlusion

INTRODUCTION

Identification of the primary feeding vessel and its removal with corresponding lymphatics is crucial for oncologic bowel resection for colon cancer. However, this notion would be challenged if we encountered abnormal mesenteric vascular anatomy. We report a case of colon cancer with abnormal mesenteric circulation, for whom we performed oncologic colectomy with vascular reconstruction.

PRESENTATION OF CASE

A 61-year-old man presented with obstructing transverse colon cancer. A contrast-enhanced computed tomography (CT) scan showed complete occlusion at the root of the superior mesenteric artery (SMA) and the celiac artery (CA), with evidently dilated marginal artery (MA). An X-ray angiography revealed retrograde arterial blood flow originating from the inferior mesenteric artery (IMA) via the MA, the SMA, and to the CA. At laparotomy, we found remarkably dilated MA with the mid-transverse colon cancer. There were no other communicating vessels between the IMA and the SMA. Right colectomy with proper lymph node dissection was completed, following vascular anastomosis between the MA to the SMA. His postoperative course was uneventful. A postoperative CT angiography showed revascularization of the areas where the SMA and the CA supplied.

DISCUSSION

In this patient, if the abberant mesenteric circulation remained unrecognized at the time of surgery, and the MA were divided without vascular reconstruction, severe ischemia and subsequent gangrene of large part of the visceral organs would have occurred.

CONCLUSION

This case illustrates the fundamental importance of assessment for vascular anatomy in patients undergoing oncologic abdominal surgery which associates with division of major mesenteric arteries.

Altered position of the medial lingual nutritional foramina at different stages of alveolar ridge atrophy

To determine the altered location of the medial lingual nutritional foramina in different stages of bone resorption, 55 cadaveric mandibles were selected for this study from a total of 1532. Prevalence, location of the foramen (lingual, cranial, labial), application of Atwood classification (grades 1-6), and macroanatomic dissections were tools of this examination. An increasing grade of atrophy leads to a shift in position of the medial lingual nutritional foramen.

Mesenteric vasculature and collateral pathways

The arterial and venous circulation of the bowel is complex and is characterized by marked redundancy of multiple interconnecting branches, which provides a rich blood supply to aid in the digestive process and also serves to protect the bowel from potential ischemia or infarction. As a result of this circulatory pattern, anatomic variants and extensive collateral pathways are common. A thorough knowledge of both the arterial and venous mesenteric circulation, including normal, variant, and collateral anatomy, is necessary for the appropriate evaluation and management of the various disease processes that may affect the vascular supply of the gastrointestinal system.

Reduction of oxygenation and blood flow in pedicled bowel segments in the rat and its consequences for anastomotic healing

PURPOSE

Experimental studies indicate that perioperative hypoperfusion impairs anastomotic healing. In bowel surgery, the part of bowel that will be anastomosed is often pedicled, leaving the blood supply dependent on the marginal artery only. Little is known about the blood supply in such a segment, and whether anastomotic strength is affected when flow would be reduced. This study describes oxygenation and blood flow in pedicled bowel segments in the rat and investigates whether early anastomotic strength changes with variations in blood flow.

METHODS

In rats, pedicled segments were created in ileum and colon by successive ligation of the feeding arteries. Oxygenation and blood flow were measured in the distal part of this segment by use of near-infrared spectroscopy with indocyanine green as an intravascular tracer. In a second experiment, a short pedicled colonic segment was created and, after flow measurements, an anastomosis was constructed. Wound strength and hydroxyproline content were analyzed 2 and 5 days after operation.

RESULTS

After creation of a pedicled segment, the concentration of oxygenated hemoglobin decreased significantly. Blood flow also significantly decreased to even less than 10% of baseline. A very large variation was observed between animals, in particular, after ligation of the first arteries. The strength of colonic anastomoses was not significantly correlated with the blood flow in the pedicled segment before anastomotic construction.

CONCLUSIONS

The creation of a pedicled bowel segment greatly reduces tissue oxygenation and blood flow to its distal part. Such impaired perioperative flow does not significantly affect early wound strength after anastomotic construction.

Mesenteric involvement in giant cell arteritis. An underrecognized complication? Analysis of a case series with clinicoanatomic correlation

We reviewed the clinical manifestations of mesenteric vasculitis due to giant cell arteritis (GCA) and considered features of the mesenteric anatomy in relationship to disease expression. We compiled and reviewed a case series by systematic identification of patients previously reported in the English-language literature to have mesenteric involvement from known GCA. Included in the analysis was a detailed case review of a patient with GCA and small bowel infarction seen at our institution. Twelve patients were identified with mesenteric ischemia attributed to GCA. Concomitant cranial and abdominal symptoms were present in 7 of the 12 patients, and cranial symptoms were absent in 5 patients who presented with abdominal complaints. The abdominal symptoms fell within a spectrum ranging from chronic postprandial symptoms to acute abdominal pain. Survival was observed in only 6 of the 12 cases, 3 of whom required bowel resection and were treated with high-dose corticosteroids. Review of the anatomic features of the specialized splanchnic circulation reveals an extensive collateral network that may protect against early disease expression from ischemia, despite mesenteric arteritic involvement. Mesenteric vasculitis resulting in small bowel infarction has only rarely been described in GCA but represents a serious and potentially treatable complication. We propose an explanation, based on mesenteric vascular anatomy, for the infrequency of symptomatic expression of this entity and suggest that occult mesenteric GCA may be present far more often than recognized.

Riolan's arch: confusing, misnomer, and obsolete. A literature survey of the connection(s) between the superior and inferior mesenteric arteries

BACKGROUND

There are 2 interpretations of Riolan's arch: (1) Riolan's arch is identical to a central part of the marginal artery (MA), connecting the superior (SMA) and the inferior mesenteric (IMA) arteries; and (2) Riolan's arch represents a rare artery, connecting the SMA and the IMA. The current review aims to emphasize the clinical importance of the colon's vasculature and to show the feasibility of abolishing the terms "Riolan's arch" and "meandering mesenteric artery."

METHODS

A literature survey was performed.

RESULTS

It appears that no distinct identity can be ascribed to Riolan's arch and that the "meandering mesenteric artery" represents an angiographically hypertrophied MA and/or the ascending branch of the left colic artery. However, a rare, centrally located, communicating artery has been described. Generally, the MA is sufficient for left colic circulation after ligation of the IMA, but at the splenic flexure, patency of the ascending branch of the left colic artery can be primordial.

CONCLUSION

As connections between the SMA and the IMA can be adequately described using structures mentioned in Terminologica Anatomica, the terms "Riolan's arch" and "meandering mesenteric artery" should be abolished.