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

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.

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

INTRODUCTION

We aimed to investigate manual subtraction computed tomography angiography (MS-CTA) to further confirm the distribution and classification of LCA (left colic artery) ascending/descending branches, then observe the postoperative blood flow path to illustrate how the above branches evolved to postoperative blood path.

MATERIAL AND METHODS

89 patients with distal sigmoid and rectal cancer were referred in our observation and underwent MS-CTA between June 2020 and March 2022. We classified the distribution of LCA and confirmed whether there exists AMCA (accessory middle colic artery). Then we planned blood flow path based on the classification of LCA branches before operation. High ligation was applied in regular radical surgery. During operation, we carefully protect the bifurcation of ascending and descending LCA. Then we compared the planned blood flow path with the actual postoperative blood flow path to verify the mechanism we proposed previously.

RESULTS

Of 89 patients, 82 cases met our criteria, we summarized 6 distribution pattens of LCA ascending and descending branches. These preoperative pattens are consistent with the inspection during operation. The postoperative blood flow path of 6 pattens is evolved from the above adjacent anastomotic branches and is consistent with the planned blood flow path. We also found 2 cases with IMA stenosis and 1 case with SMA stenosis under pathological condition, and their compensatory blood flow path is in accordance with our theory. The rate of the anastomotic leakage in our study group is relatively low (7.3%).

CONCLUSION

MS-CTA could confirm the distribution of LCA and AMCA, display accurate postoperative blood reconstruction path after IMA high ligation, and it further verified the mechanism we proposed previously, which is the proximal anastomotic branches forming new blood flow path from high-pressure area to the low-pressure area. This mechanism might be helpful for performing accurate laparoscopic sigmoid and rectal cancer surgery.

Discontinuity of marginal artery at splenic flexure and rectosigmoid junction: A systematic review and meta-analysis

AIM

The aim of this study was to provide comprehensive evidence-based assessment of the discontinuity of the marginal artery at the splenic flexure (SF) and the rectosigmoid junction (RSJ).

METHOD

A systematic review was conducted of literature published to 26 December 2022 in the electronic databases PubMed, SCOPUS and Web of Science to identify studies eligible for inclusion. Data were extracted and pooled into a meta-analysis using the Metafor package in R. The primary outcomes were the pooled PPEs of the marginal artery at the SF and the RSJ. The secondary outcome was the size of vascular anastomoses.

RESULTS

A total of 21 studies (n = 2,864 patients) were included. The marginal artery was present at the splenic flexure in 82% (95% CI: 62-95) of patients. Approximately 81% (95% CI: 63-94%) of patients had a large macroscopic anastomosis, while the remainder (19%) had small bridging ramifications forming the vessel. The marginal artery was present at the RSJ in 82% (95% CI: 70-91%) of patients.

CONCLUSION

The marginal artery may be absent at the SF and the RSJ in up to 18% of individuals, which may confer a higher risk of ischaemic colitis. As a result of high interstudy heterogeneity noted in our analysis, further well-powered studies to clarify the prevalence of the marginal artery at the SF and the RSJ, as well as its relationship with other complementary colonic collaterals (intermediate and central mesenteric), are warranted.

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%.

The retrocolic fascial system revisited for right hemicolectomy with complete mesocolic excision based on anatomical terminology: do we need the eponyms Toldt, Gerota, Fredet and Treitz?

AIM

Right hemicolectomy with complete mesocolic excision (CME) requires the removal of an intact mesocolic envelope. The study aimed to determine, on the basis of macroscopic and microscopic anatomical studies, the optimal surgical dissection planes for CME to preserve fascial integrity. Unequivocal anatomical nomenclature was applied to describe the retrocolic fascial system and compared to frequently used eponyms (Toldt, Gerota, Fredet, Treitz).

METHOD

Stepwise macroscopic dissections, cross-section studies and histological analysis were performed on body donors to identify the components of the retrocolic fascial system. Based on these anatomical findings, the optimal surgical dissection planes for CME were validated in laparoscopic training courses on body donors and in robot-assisted surgical procedures in patients.

RESULTS

The mesocolic tissue and lymphovascular pedicles were enveloped by the ventral and dorsal mesocolic leaf (mesocolic fascia). The mesocolic fascia was attached to the parietal peritoneal fascia ('fascia of Toldt') along the parieto-mesocolic interface, and further cranially to the pre-duodenopancreatic fascia along the mesocolic-duodenopancreatic interface ('space of Fredet'). Dorsally, the parietal peritoneal fascia was separated from the anterior renal fascia ('fascia of Gerota') by the parieto-renal interface. Dissection along this interface in front of the anterior renal fascia followed by incision of the parietal peritoneal fascia at the duodenal border and opening the mesocolic-duodenopancreatic interface yielded the best macroscopic appearance of specimens and was considered optimal for CME.

CONCLUSION

The retrocolic fascial system as well as the surgical dissection planes for CME can be described by clearly defined anatomical terms rather than potentially confusing eponyms.

Successful coil embolization of a ruptured aneurysm of the arc of Riolan artery

The arc of Riolan (AOR) is an anastomosis between the middle and left colic arteries. Aneurysms of the AOR are very rare visceral artery aneurysms. A 44-year-old man presented with abdominal pain and loss of consciousness. Computed tomography and angiography showed hemorrhagic ascites around the liver and spleen. An irregularly dilated artery was visible within a hematoma in the upper left region of the abdomen, consistent with a ruptured pseudoaneurysm of the AOR. Transcatheter arterial embolization was performed with microcoils. The patient's abdominal pain disappeared after embolization, and no symptoms of intestinal ischemia were observed. To our knowledge, this is the first case of an AOR aneurysm with AOR dilation due to dissection of the celiac artery that was successfully treated by coil embolization.

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.

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.

Surgical outcomes of various surgical approaches for transverse colon cancer

The transverse colon has anatomical peculiarities in the middle position between the foregut and the midgut. Because the transverse colon harbors a flexure at both ends, mobilization of the transverse colon can be especially challenging compared with other colons. Although transverse colon cancer is relatively uncommon, an optimal surgical management for transverse colon cancer must be established. In transverse colon cancer, proximity to the pancreas and variation in arterial and venous anatomy make radical resection more difficult. Dissection of lymph nodes around the middle colic vessels is a critical step in transverse colon cancer resection. The proximity of the middle colic vessels to the superior mesenteric vessels contributes to the complexity of this step, making it challenging for less-trained surgeons. For these reasons, patients with transverse colon cancer were not included in most landmark studies that compared laparoscopic surgery with open surgery. More radical operations, such as subtotal colectomy or extended right or left hemicolectomy, can be performed for transverse colon cancer to secure an adequate lymphadenectomy. Such cancers have also been treated with limited segmental colectomies, such as right, transverse, or left colectomy. Currently, there is still a lack of standardized definitions and procedures. Therefore, it is time to discuss and establish optimal surgical treatments for transverse colon cancer.

Arterial supply to the rat colon

Rats are often used as animal models in studies such as on intestinal transplantation and anastomosis healing, which require colectomy. Although detailed information regarding arterial supply is important to establish accurate and reproducible experimental procedures, this has not been studied in the rat colon. Therefore, we analysed the detailed arterial distribution pattern and its individual variations in the colon of 34 rats. The rat colon received colic branches of the ileocolic artery, and the right, middle and left colic arteries. The single left colic artery constantly arose from the caudal mesenteric artery and was distributed to the descending colon, whereas the others showed variations in number and distribution. The ileocolic artery gave rise to one (12%) or two (88%) colic branches supplying the proximal ascending colon, and these branches formed rich, mesh-like anastomoses along the initial portion of the ascending colon. One (74%) or two (26%) right colic arteries originated from the cranial mesenteric artery and supplied the ascending colon and right colic flexure. Moreover, one (38%), two (56%) or three (6%) middle colic arteries emerged from the cranial mesenteric artery and were distributed to the transverse colon, left colic flexure and proximal descending colon. In total, we categorized the individual variations in arterial branching and anastomosis into 11 patterns. Arterial supply to the rat colon showed a specific pattern and frequent individual variations. These findings thus provide essential information for establishing reproducible models of rat colic surgery.

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.

The New Concept of Physiological "Riolan's Arch" and the Reconstruction Mechanism of Pathological Riolan's Arch After High Ligation of the Inferior Mesenteric Artery by CT Angiography-Based Small Vessel Imaging

Background

Due to the complexity of anatomical relationship between superior mesenteric artery (SMA) and left colic artery (LCA), there is no unified anatomical concept of "Riolan's arch." There is no consensus as to tie off the inferior mesenteric artery (IMA) at its origin or just below the origin of the left colic artery during radical surgery of sigmoid colon and rectal cancers. The aim of the study is to investigate the anatomy of shortcut anastomotic branches (adjacent branches) of SMA at splenic flexure and to explore how the shortcut pathway (Riolan's arch) was formed, as the compensation of anastomotic branches between MCA and LCA under pathological conditions and the reconstruction and the mechanism of pathological Riolan's arch after high ligation of the inferior mesenteric artery.

Methods

Between January 2018 and May 2020, patients with colorectal cancer who underwent CTA before surgery were enrolled in the study. The anatomy of shortcut anastomotic branch of SMA and LCA was investigated by volume rendering technique (VR) and maximum-intensity projection (MIP). GE's small vessel extraction technology (selected VR) was used to directly display these shortcut anastomotic branches on a map and to establish their three-dimensional anatomical classification. Then, we used the axonometric drawing to make the model more exact. Next, combining with some cases of pathological Riolan's arch and basing on hydrodynamic principle, we speculate the mechanism of collateral circulation. Finally, based on the retrospective study of high ligation cases and combined principles of fluid mechanics, we show how these shortcut anastomotic branches evolved into Riolan's arch.

Results

We report the classification of the ascending branch of LCA (which approaches the splenic flexure) and the left branch of MCA, display these shortcut anastomotic branches on a map, and establish their three-dimensional anatomical classification. We found that Riolan's arch is a shortcut pathway for the compensation of anastomotic branches, between MCA and LCA under pathological conditions, and that the formation mechanism of shortcut path accords with the principle of hydrodynamics.

Conclusions

Our results show the mechanism of pathological Riolan's arch formation and provide new anatomic thinking for the battle between high and low ligation of IMA in colorectal cancer surgery.

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.

Large Bowel Ischemia/Infarction: How to Recognize It and Make Differential Diagnosis? A Review

Ischemic colitis represents the most frequent form of intestinal ischemia occurring when there is an acute impairment or chronic reduction in the colonic blood supply, resulting in mucosal ulceration, inflammation, hemorrhage and ischemic necrosis of variable severity. The clinical presentation is variable and nonspecific, so it is often misdiagnosed. The most common etiology is hypoperfusion, almost always associated with generalized atherosclerotic disease. The severity ranges from localized and transient ischemia to transmural necrosis of the bowel wall, becoming a surgical emergency, with significant associated morbidity and mortality. The diagnosis is based on clinical, laboratory suspicion and radiological, endoscopic and histopathological findings. Among the radiological tests, enhanced-CT is the diagnostic investigation of choice. It allows us to make the diagnosis in an appropriate clinical setting, and to define the entity of the ischemia. MR may be adopted in the follow-up in patients with iodine allergy or renal dysfunctions, or younger patients who should avoid radiological exposure. In the majority of cases, supportive therapy is the only required treatment. In this article we review the pathophysiology and the imaging findings of ischemic colitis.

CT Angiography of the Arc of Riolan

Online supplemental material is available for this article.

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.

Evaluation of characteristics of left-sided colorectal perfusion in elderly patients by angiography

BACKGROUND

Handling of the inferior mesenteric artery (IMA) and maintaining anastomotic perfusion are important in radical resection of left-sided colorectal cancer. However, the branching of this artery and the drainage patterns of this vein vary among individuals, and the characteristics and perfusion region of this artery in elderly patients remain unclear.

AIM

To evaluate the characteristics and perfusion region of the IMA in elderly patients using angiography.

METHODS

We enrolled 154 patients (> 65 years old) who underwent digital subtraction angiography of the IMA. The characteristics, bifurcation, and distribution of the IMA and termination of the anastomotic perfusion of the left colon and rectum were examined using digital subtraction angiography. Collateral arterial arches and the IMA hemoperfusion region were also recorded. Perfusion regions were cross-referenced with clinical and anatomical features by the univariate analysis.

RESULTS

Of 154 patients, 25 (16.2%) had IMA lesions. The left colic artery arose independently from the IMA in 44.2% of patients, shared a trunk with the sigmoid artery in 35.1%, shared an opening with the sigmoid and superior rectal arteries in 16.9%, and was absent in 5.1%. The IMA perfusion region stopped at the splenic flexure in 50 (32.5%) patients. The collateral circulation existed in the colonic perfusion region, including the marginal artery (Drummond’s artery), the ascending branch of the left colonic artery to supply the transverse colon, and the arc of Riolan with a frequency of 100%, 22.7%, and 1.9%, respectively. The IMA perfusion region was independently associated with the comorbidity of atherosclerosis, IMA atherosclerotic lesion, branching pattern, collateral circulation, and marginal artery integrity.

CONCLUSION

The IMA and its branches are prone to arteriosclerosis, and IMA perfusion may be interrupted at the splenic flexure in elderly patients. The applicability and precision of preoperative angiography for evaluating the IMA branching and perfusion patterns could facilitate geriatric laparoscopic left-sided colorectal cancer surgery with suspicion of poor IMA perfusion.

Low ligation has a lower anastomotic leakage rate after rectal cancer surgery

BACKGROUND

For laparoscopic rectal cancer surgery, the inferior mesenteric artery (IMA) can be ligated at its origin from the aorta [high ligation (HL)] or distally to the origin of the left colic artery [low ligation (LL)]. Whether different ligation levels are related to different postoperative complications, operation time, and lymph node yield remains controversial. Therefore, we designed this study to determine the effects of different ligation levels in rectal cancer surgery.

AIM

To investigate the operative results following HL and LL of the IMA in rectal cancer patients.

METHODS

From January 2017 to July 2019, this retrospective cohort study collected information from 462 consecutive rectal cancer patients. According to the ligation level, 235 patients were assigned to the HL group while 227 patients were assigned to the LL group. Data regarding the clinical characteristics, surgical characteristics and complications, pathological outcomes and postoperative recovery were obtained and compared between the two groups. A multivariate logistic regression analysis was performed to evaluate the possible risk factors for anastomotic leakage (AL).

RESULTS

Compared to the HL group, the LL group had a significantly lower AL rate, with 6 (2.8%) cases in the LL group and 24 (11.0%) cases in the HL group (P = 0.001). The HL group also had a higher diverting stoma rate (16.5% vs 7.5%, P = 0.003). A multivariate logistic regression analysis was subsequently performed to adjust for the confounding factors and confirmed that HL (OR = 3.599; 95%CI: 1.374-9.425; P = 0.009), tumor located below the peritoneal reflection (OR = 2.751; 95%CI: 0.772-3.985; P = 0.031) and age (≥ 65 years) (OR = 2.494; 95%CI: 1.080-5.760; P = 0.032) were risk factors for AL. There were no differences in terms of patient demographics, pathological outcomes, lymph nodes harvested, blood loss, hospital stay and urinary function (P > 0.05).

CONCLUSION

In rectal cancer surgery, LL should be the preferred method, as it has a lower AL and diverting stoma rate.

European guidelines on chronic mesenteric ischaemia - joint United European Gastroenterology, European Association for Gastroenterology, Endoscopy and Nutrition, European Society of Gastrointestinal and Abdominal Radiology, Netherlands Association of Hepatogastroenterologists, Hellenic Society of Gastroenterology, Cardiovascular and Interventional Radiological Society of Europe, and Dutch Mesenteric Ischemia Study group clinical guidelines on the diagnosis and treatment of patients with chronic mesenteric ischaemia

Chronic mesenteric ischaemia is a severe and incapacitating disease, causing complaints of post-prandial pain, fear of eating and weight loss. Even though chronic mesenteric ischaemia may progress to acute mesenteric ischaemia, chronic mesenteric ischaemia remains an underappreciated and undertreated disease entity. Probable explanations are the lack of knowledge and awareness among physicians and the lack of a gold standard diagnostic test. The underappreciation of this disease results in diagnostic delays, underdiagnosis and undertreating of patients with chronic mesenteric ischaemia, potentially resulting in fatal acute mesenteric ischaemia. This guideline provides a comprehensive overview and repository of the current evidence and multidisciplinary expert agreement on pertinent issues regarding diagnosis and treatment, and provides guidance in the multidisciplinary field of chronic mesenteric ischaemia.

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

AIM

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

METHOD

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

RESULTS

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

CONCLUSION

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

Arterial vascularization of the right colon with implications for surgery

PURPOSE

During right-sided colectomies, surgeons encounter major anatomical variations at the level of the right colon, leading to morbidity. Due to the confusion surrounding the colonic arterial vessels emerging from the superior mesenteric artery (SMA) to vascularize the right part of the colon, this review aimed to describe the arterial vessels found in the mesocolic structures of the ascending colon, the hepatic flexure and the right transverse colon.

METHODS

A review of the literature was performed using the MEDLINE database. Only human studies were included. All dissection, angiographic, arterial cast and corrosion studies were analyzed.

RESULTS

This review demonstrates that the right colon, the hepatic flexure and the right transverse colon are vascularized by three significant arteries emerging from the SMA and forming one peripheral paracolic arc: (1) the ileocolic artery (ICA), the most constant vessel (99.8%) with low variability; (2) the right colic artery (RCA), the most inconstant vessel (2/3 of cases) with high variability in its origin; and (3) the middle colic artery (MCA), a constant vessel (95%) with variation in its origin and its number. The marginal artery is almost constant (100%) and represents the only peripheral arterial arc at the level of the right side of the colon.

CONCLUSIONS

Three arteries emerging from the superior mesenteric artery exist: the ICA, the RCA and the MCA. The ICA and the MCA are the most constant. Knowledge of this vascular anatomy is essential for performing right-sided colectomies.

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.

Retrocolic versus antecolic gastrointestinal reconstruction in robotic pancreaticoduodenectomy

BACKGROUND

With the advancement of robotic pancreaticoduodenectomy (RPD), several reconstruction methods have been advocated to make RPD more effective and safer. In this study, we investigated the safety and effectiveness of RPD using a left retrocolic (L-port) technique and compared it with those of RPD using an antecolic technique.

METHODS

Between October 2015 and August 2016, we retrospectively reviewed consecutive cases of RPD before and after introducing the L-port technique for gastrointestinal reconstruction. The L-port technique was mainly performed for retrocolic gastrojejunal reconstruction and some cases of duodenojejunal reconstruction. The perioperative and postoperative outcomes were compared in the two groups.

RESULTS

Eighty-three cases of RPD were retrieved for statistical analysis. Compared with the antecolic group, the L-port group was significantly associated with a shorter operative time (median time [IQR] 345 [307-384] min vs. 390 [370-455] min, P < 0.001), reconstruction time (54 [48-59] min vs. 84 [75-98] min, P < 0.001) and lower incidence of delayed gastric emptying. There were no cases of re-operation due to internal herniation, colonic ischemia, or bowel volvulus in the L-port group during the 1-year follow-up period.

CONCLUSIONS

Our results demonstrated that the L-port technique of RPD is a safe and feasible technique for gastrointestinal reconstruction.

Standardize the Surgical Technique and Clarify the Relevant Anatomic Concept for Complete Mobilization of Colonic Splenic Flexure Using da Vinci Xi® Robotic System

BACKGROUND

The present study is to set up a standardized approach for complete mobilization of colonic splenic flexure using da Vinci Xi^® robotic system, based on clarification of the mesenteric structures of distal transverse colon.

METHODS

The surgical outcomes and relevant anatomic structures of 104 consecutive patients undergoing robotic resection of primary colorectal cancer with the intent of complete mobilization of colonic splenic flexure using da Vinci Xi^® robotic system were retrospectively reviewed.

RESULTS

Complete mobilization of colonic splenic flexure can be efficiently performed by the Xi^® robotic system, as demonstrated by short operation time, minimal intra-operative blood loss, and few surgical complications. Xi^® robotic system has overcome the drawbacks of Si^® robotic system for the mobilization of colonic splenic flexure. The present study defined the following anatomic hallmarks for the colonic splenic flexure: (1) The transverse mesocolon distal to the inferior mesenteric vein adheres to the low border of pancreas by the avascular fibrous connective tissues, which have been inappropriately named as "mesenteric root"; (2) The colonic splenic flexure abuts closely to spleen with an acute angle in 78.85% (n = 82/104); (3) Only a minority of patients presented with the Riolan branch (15.38%, n = 16/104) or the Moskowitz artery (8.65%, n = 9/104).

CONCLUSION

With increased maneuverability of Xi^® robotic arms and the clarification of relevant anatomic concept, the surgical technique for the complete mobilization of colonic splenic flexure can be standardized; and the standardization of surgical technique is the first step toward the enhanced automation in the rapidly evolving robotic systems.

Changes in Clinical Practice Reduce the Rate of Anastomotic Leakage After Colorectal Resections

Background

Anastomotic leakage is a serious clinical problem after colorectal resections and is associated with a significantly increased length of stay, morbidity and mortality. The aim of the present study was to evaluate the effect of changes in clinical practice on anastomotic leakage rate after colorectal resections.

Methods

Retrospective cohort study based on prospectively collected data. All 894 patients with primary anastomosis after colorectal resection at a tertiary referral center between 2006 and 2013 were analyzed. Changes in clinical practice aiming at reducing the rate of anastomotic leakages were introduced in January 2010 and were characterized by exclusion of perioperative nonsteroidal anti-inflammatory drugs, introduction of intra-operative goal-directed fluid therapy and avoidance of primary anastomoses in emergency resections. The study population was divided into two groups, one treated before and one after the introduction of changes in clinical practice. Groups were compared regarding patient characteristics and incidence of anastomotic leakage.

Results

The cumulative incidence of anastomotic leakage after colorectal resections decreased from 10.0% (41 of 409) to 4.5% (22 of 485) after changing clinical practice, relative risk 0.45 (95% CI 0.27–0.75, p = 0.002). The adjusted odds ratio was 0.45 (0.26–0.78, p = 0.004). A separate analysis showed a decrease after colon resections from 9.1% (23 of 252) to 4.5% (14 of 310), relative risk 0.49 (0.26–0.94, p = 0.039), and from 11.5% (18 of 157) to 4.6% (8 of 175) after rectal resections, relative risk 0.40 (0.18–0.89, p = 0.024).

Conclusion

Implementing a structured change of clinical practice can significantly reduce the anastomotic leakage rate after colorectal resections.

Trial registration

Clinical trial registration number: ACTRN12617001497392.

Assessment of Blood Flow Patterns Distal to Aortic Occlusion Using CT in Patients with Resuscitative Endovascular Balloon Occlusion of the Aorta

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is used to decrease hemorrhage below the level of aortic occlusion (AO); however, the amount of collateral blood flow below the level of occlusion is unknown. Our aim was to investigate blood flow patterns during complete AO in patients who underwent CT scan after REBOA.

STUDY DESIGN

Between February 2013 and January 2017, patients who received REBOA and underwent CT scan with intravenous contrast during full AO were included. Patients were excluded if they had a CT scan performed with the balloon partially or fully deflated.

RESULTS

Nine patients (8 men) were included; all had blunt trauma. Mean Injury Severity Score (±SD) was 48 ± 8 and mean age was 45 ± 19 years. Four had supra-celiac AO, and 5 had infra-renal AO. Arterial contrast enhancement was noted below the level of AO in all patients, and distal to REBOA sheath placement in 5. Collateralization from arteries above and below the AO was identified in all patients. Contrast extravasation distal to AO was identified in 4 patients, and hematomas in 8. Distal vascular enhancement patterns varied by level of AO and contrast administration site.

CONCLUSIONS

Aortic occlusion appears to dramatically decrease, but does not completely impede, distal perfusion during REBOA due to multiple pathways of collateralization. Active extravasation and hematomas can still be detected in the setting of full AO, with purposefully timed contrast and image acquisition. Blood flow persists below the level of both the AO and in-dwelling sheath. Dynamic flow studies are needed to determine the contribution of AO and sheath placement to distal tissue ischemia.

Low-tie IMA and selective D3 lymph node sampling in laparoscopic rectal resection for carcinoma rectum: comparison of surgical and oncological outcomes with the open technique

Background

Level of proximal lymphovascular ligation remains controversial in carcinoma rectum. High-tie inferior mesenteric artery (IMA) claims better lymph node clearance; low-tie IMA minimizes autonomic nerve injury (ANI) and ensures vascularity to anastomosis. Objective of this study is to compare postsurgical complications and oncological clearance in laparoscopic rectal resection (LRR) and open rectal resection (ORR) for carcinoma rectum, with low-tie IMA and selective D3 lymphadenectomy.

Methods

Retrospective analysis was done comparing LRR and ORR done with low-tie IMA for carcinoma rectum/rectosigmoid for significant differences (P<0.05) regarding postsurgical complications and histopathology parameters.

Results

A total of 118 patients; 48 in LRR group and 70 in ORR group were studied. They were comparable in age, site of lesion and clinical TNM (cTNM) stage. Comorbidities and symptoms requiring upfront surgery were more among ORR. 75% LRR and 55.3% ORR had neoadjuvant chemoradiation (NACRT). Duration of surgery was longer in LRR. Clavien-Dindo grade >3 was similar in two groups. Histopathology characteristics were also comparable; including specimen length, lymph node yield, length of distal margin and pathologic TNM (pTNM) stage. Selective D3 lymphadenectomy was done in 37.5% LRR and 37.14% ORR. And 4.16% in LRR and 4.28% in ORR were had positive IMA root lymph nodes.

Conclusions

The post-surgical complications and oncological clearance of LRR done with low-tie IMA and selective D3 lymphadenectomy were found equivalent to ORR. Low-tie IMA without routine splenic flexure mobilisation had no technical issues regarding the anastomosis.

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.

Ileum preserving expanded jejunectomy and pancreaticoduodenectomy with combined resection of the superior mesenteric artery for huge retroperitoneal solitary fibrous tumor

We encountered a patient with a large retroperitoneal solitary fibrous tumor, in whom we could preserve approximately 150 cm of the ileum even after pancreaticoduodenectomy combined with resection of the superior mesenteric artery, thus preventing short bowel syndrome.

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.

A rare branching pattern of hindgut: absence of inferior mesenteric artery

The arterial system of the gastrointestinal tract has many variations. However, variation in the inferior mesenteric artery (IMA) is less common than for the other abdominal arteries. The case in the present cadaver subject showed a variation in the anatomy of the IMA that differed from those seen in previous studies, because it did not originate from the abdominal aorta and had no branches. A single artery arising from branches of the inferior pancreaticoduodenal and middle colic arteries supplied the hindgut. This variation generated blood vessels along the digestive tract during the later stages of development. The marginal artery of the colon in this case probably was more highly developed instead of the IMA. It is clinically important to know the range of variations, as these data are used in the diagnosis and treatment of abdominal diseases. This hitherto unknown variation might affect the health of patients, and we recommend radiographic examinations for diagnosis and treatment.

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.

Technical difficulties of left colic artery preservation during left colectomy for colon cancer

PURPOSE

Low-tie ligation in colorectal cancer surgery is associated with technical difficulties in left colic artery preservation. We aimed to evaluate and classify the anatomical and technical difficulties of left colic artery (LCA) preservation at its origin and along its route at the inferior border of the pancreas.

METHODS

A vascular reconstruction computed tomography prospective series of 113 patients was analyzed. The inferior mesenteric artery (IMA) branching pattern according to Latarjet's classification (Type I, separate LCA origin, Type II, fan-shaped branching pattern) and the distances between the IMA and the LCA origins and between the LCA and the Inferior mesenteric vein (IMV) at the inferior border of the pancreas were measured.

RESULTS

The IMA branching pattern was Type I in 80 (71 %) patients and Type II in 33 (29 %) patients. The IMA-LCA distance was 39.8 ± 12.2 mm. The LCA-IMV distance at the inferior border of the pancreas was 20.5 ± 21.7 mm. When classified based on this distance, 75 (66 %) patients were classified into the Near subgroup (<20 mm) (7.7 ± 4.1 mm) and 38 (34 %) into the Far subgroup (≥20 mm) (45.6 ± 20.4 mm, p < 0.001). A Type I subgroup F accounted for 27 % of the patients.

CONCLUSIONS

Left colic artery preservation is highly feasible at its origin in more than two-thirds of cases due to the separate origin. The addition of a high IMV ligation increases the risk of damage to the LCA at the inferior border of the pancreas because the distance to the IMV is less than 20 mm in two-thirds of cases.

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.

The rationale behind complete mesocolic excision (CME) and a central vascular ligation for colon cancer in open and laparoscopic surgery : proceedings of a consensus conference

BACKGROUND

It has been evident for a while that the result after resection for colon cancer may not have been optimal. Several years ago, this was showed by some leading surgeons in the USA but a concept of improving results was not consistently pursued. Later, surgeons in Europe and Japan have increasingly adopted the more radical principle of complete mesocolic excision (CME) as the optimal approach for colon cancer. The concept of CME is a similar philosophy to that of total mesorectal excision for rectal cancer and precise terminology and optimal surgery are key factors.

METHOD

There are three essential components to CME. The main component involves a dissection between the mesenteric plane and the parietal fascia and removal of the mesentery within a complete envelope of mesenteric fascia and visceral peritoneum that contains all lymph nodes draining the tumour area (Hohenberger et al., Colorectal Disease 11:354-365, 2009; West et al., J Clin Oncol 28:272-278, 2009). The second component is a central vascular tie to completely remove all lymph nodes in the central (vertical) direction. The third component is resection of an adequate length of bowel to remove involved pericolic lymph nodes in the longitudinal direction.

RESULT

The oncological rationale for CME and various technical aspects of the surgical management will be explored.

CONCLUSION

The consensus conference agreed that there are sound oncological hypotheses for a more radical approach than has been common up to now. However, this may not necessarily apply in early stages of the tumour stage. Laparoscopic resection appears to be equally well suited for resection as open surgery.

High tie versus low tie vascular ligation of the inferior mesenteric artery in colorectal cancer surgery: impact on the gain in colon length and implications on the feasibility of anastomoses

BACKGROUND

There is no demonstrated benefit of high-tie versus low-tie vascular transections in colorectal cancer surgery.

OBJECTIVE

The aim of this study was to compare the effects of high-tie and low-tie vascular transections on colonic length after oncological sigmoidectomy, the theoretical feasibility of colorectal anastomosis at the sacral promontory, and straight or J-pouch coloanal anastomosis after rectal cancer surgery with total mesorectal excision.

DESIGN

This study is an anatomical study on surgical techniques.

SETTINGS

This study was conducted in a surgical anatomy research unit.

PATIENTS

Thirty fresh nonembalmed cadavers were randomly assigned to high-tie and low-tie groups (n = 15).

INTERVENTIONS

Oncological sigmoidectomy followed by total mesorectal excision was performed.

MAIN OUTCOME MEASURES

The distances from the proximal colon limb to the lower edge of the pubis symphysis were recorded after each step of vascular division.

RESULTS

The successive mean gains in length in high-tie vs low-tie vascular transections were 2.9±1.2 cm vs 3.1 ± 1.8 cm (p = 0.83) after inferior mesenteric artery division, 8.1 ± 3.1 cm vs 2.5 ± 1.2 cm (p = 0.0016) after inferior mesenteric vein division at the lower part of the pancreas, 8.1 ± 3.8 cm vs 3.3 ± 1.7 cm (p = 0.0016) after sigmoidectomy. The mean cumulative gain in length was significantly higher in high-tie vs low-tie vascular transections (19.1 ± 3.8 vs 8.8 ± 2.9 cm, p = 0.00089). After secondary left colic artery division, the gain in length was similar to that of the high-tie group (17 ± 3.1 vs 19.1 ± 3.8 cm) (p = 0.089). Colorectal anastomosis at the promontory and straight and J-pouch coloanal anastomosis feasibility rates were 100% in the high-tie group, 87%, 53%, and 33% in the low-tie group, but 100%, 100%, and 87% after secondary left colic artery division.

LIMITATIONS

This anatomical study, based on cadavers rather than live patients, does not evaluate colon limb vascularization.

CONCLUSIONS

The gain in colonic length is 10 cm greater for high-tie vascular transections. With low-tie vascular transections, high inferior mesenteric vein division produced a small additional gain in length, and secondary left colic artery division produced the same length gain as high-tie vascular transections.

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.

Intraoperative pulmonary artery stenting in aortoarteritis: a hybrid procedure

A 40-year old male presented with history of dyspnea and recurrent syncope. Preliminary evaluation revealed findings suggestive of severe pulmonary hypertension. His echocardiogram revealed severe stenosis of the right pulmonary artery (RPA) with severe pulmonary hypertension, which was confirmed on 64-slice MSCT. On cardiac catheterization, the stenotic segment could not be crossed. Hence he underwent surgical reconstruction of the RPA. Post-operatively, he developed arterial desaturation and hypotension due to compression of the reconstructed segment by the ascending aorta. Subsequently, intraoperative direct stenting of the RPA was performed on a beating heart. Post-procedure there was a significant drop in right heart pressures which was sustained on 3-month follow up. The patient also had occlusion of the Coeliac and Superior Mesenteric arteries which was demonstrated on MSCT and angiography, suggesting Aortoarteritis as the etiology. This case illustrates an unusual presentation of Aortoarteritis and the role of hybrid procedures in situations where percutaneous intervention may not be technically feasible.