Arc Of Riolan Research Articles

Virtual Monoenergetic Images Facilitate Better Identification of the Arc of Riolan During Splenic Flexure Takedown.

This study aimed to investigate whether virtual monoenergetic images (VMIs) can aid radiologists and surgeons in better identifying the arc of Riolan (AOR) and to determine the optimal kilo electron volt (keV) level. Thirty-three patients were included. Conventional images (CIs) and VMI (40-100 keV) were reconstructed using arterial phase spectral-based images. The computed tomography (CT) attenuation and noise of the AOR, the CT attenuation of the erector spinal muscle, and the background noise on VMI and CI were measured, respectively. The signal-to-noise ratio, contrast-to-noise ratio (CNR), and signal intensity ratio were calculated. The image quality of the AOR was evaluated according to a 4-point Likert grade. The CT attenuation, noise, CNR, and signal intensity ratio of the AOR were significantly higher in VMI at 40 and 50 keV compared with CI ( P < 0.001); VMI at 40 keV was significantly higher than 50 keV ( P < 0.05). No significant difference in signal-to-noise ratio, background noise, and CT attenuation of the spinal erector muscle was observed between VMI and CI ( P > 0.05). virtual monoenergetic image at 40 keV produced the best subjective scores. Virtual monoenergetic image at 40 keV makes it easier to observe the AOR with optimized subjective and objective image quality. This may prompt radiologists and surgeons to actively search for it and encourage surgeons to preserve it during splenic flexure takedown.

Spontaneous dissection of celiacomesenteric trunk with isolated extension and thrombosis in the superior mesenteric artery: a case report and literature review

BackgroundCeliacomesenteric trunk (CMT) is one of the rare congenital anomalies of the splanchnic vasculature, characterized by the common trunk origin of the superior mesenteric artery (SMA) and celiac trunk from the abdominal aorta. Dissection of CMT with isolated SMA involvement without bowel ischemia has been rarely reported in the literature.Case presentationA 48-year-old male presented with generalized abdominal pain for 20 days, which increased after food intake. He also gave a history of passing loose stools on and off in the last 10–15 days, associated with melena for 4–5 days. Computed tomography (CT) and CT angiography (CTA) study of the abdomen demonstrated the common trunk origin of SMA and celiac trunk from the abdominal aorta at the D12–L1 disk level, consistent with the celiacomesenteric trunk (CMT). CTA also revealed dissection of CMT with isolated extension in the SMA origin and thrombosis in the mid and distal SMA. No bowel or mesenteric ischemia was seen due to extensive collateral supply to distal-most SMA and its branches, mainly through the inferior mesenteric artery (IMA) via an arc of Riolan and artery of Drummond. The patient was managed conservatively with bowel rest, anti-thrombolytics, and anticoagulant therapy based on imaging findings of short-segment dissection with no signs of bowel or mesenteric ischemia.ConclusionDiagnosis of rare vascular anomalies like CMT with associated complications of dissection and thrombosis is critical in patients with abdominal pain for prompt and precise management. CTA of the abdomen is essential for accurate diagnosis and characterization of the abnormality, which helps decide between conservative and surgical treatments.

Open revascularization for chronic mesenteric ischemia in the endovascular era: a quaternary-center experience and management algorithm.

Chronic mesenteric ischemia (CMI) is a debilitating disease with a heavy burden on quality of life. Stenting of the superior mesenteric artery (SMA) is the first option for treatment, but there is a lack of consensus defining precise indications for open revascularization (OR). To describe a series of 4 patients with CMI treated with OR and to present an algorithm for the management of this condition. Three patients presented with typical intestinal angina and weight loss. One patient was subjected to prophylactic revascularization during open abdominal aortic aneurysm repair. Surgical techniques included: 1) Bypass from the infrarenal aorta to the SMA; 2) Bypass from an aorto-bifemoral polyester graft to the SMA; 3) Bypass from the right iliac artery to the SMA; 4) Bypass from the right graft limb of an aorto-biiliac polyester graft to the median colic artery at Riolan's arcade. PTFE was used in all surgeries. All grafts were placed in a retrograde configuration, tunneled under the left renal vein, making a smooth C-loop. A treatment algorithm was constructed based on the institution's experience and a review of recent literature. All patients demonstrated resolution of symptoms and recovery of body weight. All grafts are patent after mean follow-up of two years. Open revascularization using the C-loop configuration is a valuable technique for CMI and may be considered in selected cases. The algorithm constructed may help decision planning in other quaternary centers.

Arc of Riolan revisited-proposal of a new classification system.

The arterial supply of the large colon is provided by the superior mesenteric artery (SMA) and inferior mesenteric artery (IMA). A particularly important area, especially in the field of colorectal surgery is the splenic flexure of the colon. There is a noticeable misunderstanding in the correct nomenclature of the major arterial anastomoses between SMA and IMA - Drummond's Marginal Artery (DMA), Arc of Riolan (AOR), and Moskovitz Artery (MA). The aim of this study is to organize the nomenclature and propose a new simplified one to facilitate communication between physicians of various specialties. Fourteen formalin-fixed cadavers (9 male, 5 female) accessible from the Chair of Anatomy of the Jagiellonian University Collegium Medicum were dissected to examine and describe the anatomical variations of anastomoses between SMA and IMA. The artery of Drummond was present in all 14 specimens maintaining the continuity of the vessel along its entire course. The Arc of Riolan was found in 7 out of 14 cadavers (50%). The artery of Moskovitz was not found. The average length measured between IMA and aortic bifurcation and between IMA and SMA was 51,00 mm and 84,68mm respectively. CONCLUSIONS: SMA and IMA anastomoses form an arterial network that is characterized by high variability and trail in surgically strategic areas. For this reason, simplifying the terminology and using unambiguous names of these vessels based on their trail and anatomical relationship with IMV are crucial for the proper planning and execution of surgical procedures performed on the colon.

Application of meandering mesenteric artery in vascular surgery

In recent years, the therapeutic concepts and surgical methods of the meandering mesenteric artery involved in atherosclerosis have been reported in the literature, and the importance of this lateral branch circulation in the field of vascular surgery has received more attention. With the improvement of imaging techniques, the discovery rate of this collateral circulation increased. In the presence of major iliac artery occlusion, the meandering mesenteric artery may serve as an important collateral circulation to relieve ischemia in the visceral or lower extremities. The meandering mesenteric artery may also lead to type Ⅱ internal leakage after endovascular repair, while the embolization of inferior mesenteric artery may be performed through the meandering mesenteric artery. The role of meandering mesenteric arteries in vascular surgery needs further study.

Bifurcated Arc of Buhler Co-existent with an Arc of Riolan-A Rare Case Report

The Arcs of Buhler and Riolan are collateral channels that connect the major midline ventral branches of the abdominal aorta, which supply the gastrointestinal tract. These arcs occur with a relative rarity of 1-10%. During routine dissection of the abdominal cavity of a 50-year-old, embalmed male Indian cadaver in the Department of Anatomy of a National Institute in South India, the presence of a large vertical tortuous bifurcated artery was noticed, posterior to the body of the pancreas, connecting the coeliac trunk to the superior mesenteric artery. This was identified to be an Arc of Buhler (AOB) and measuring 8 mm in external diameter. In addition, an Arc of Riolan (AOR) was identified, connecting the left division of the Buhler’s arc to the left colic artery. The presence of a large bifurcated AOB or its co-existence with an AOR has not been described previously. The identification of such anastomotic channels in symptomatic patients may help in diagnosing impending bowel ischemia. Aneurysms of AOB, though rare, are life-threatening and have been treated successfully. The knowledge of mesenteric vascular anatomy is important during abdominal surgeries and endovascular procedures. Recognising a vascular variation is crucial to avoid inadvertent bleeding or bowel ischaemia.

Natural Course and Treatment of Symptomatic Spontaneous Isolated Superior Mesenteric Artery Dissection with Total True Lumen Occlusion.

We retrospectively investigated the association between the imaging features of spontaneous isolated superior mesenteric artery dissection (SISMAD) accompanied by total true lumen occlusion and the clinical symptoms to identify the patients at high risk and establish personalized therapeutic options. Among 261 patients with SISMAD, we selected 37 with Yun's type III dissection; 35 patients underwent successful conservative management and 2 patients underwent exploratory laparotomy. After discharge, all patients were periodically followed up on an outpatient basis. We recorded patients' general condition, symptoms, time until symptom relief, imaging findings and follow-up results. All patients experienced acute abdominal pain prior to admission, with an onset time of 29.95 ± 24.66hours. The mean time until relief of abdominal pain in patients who received conservative treatment was 42.17 ± 38.09hours. Correlation analysis revealed no correlation between the length of dissection or of the occluded segment and abdominal pain intensity. Pain scores were lower and time until pain relief was shorter in patients with a definite arc of Riolan (AOR) on admission than in those without an AOR. No collateral circulation was observed in the two patients who underwent exploratory laparotomy, and distal intestinal perfusion was poor in these cases. Complete and partial remodeling of the superior mesenteric artery (SMA) was observed in 6 and 16 patients, respectively at the 12-month follow-up. Although the SMA remained occluded in 12 patients, abundant collateral circulation was detected. Three patients were lost to follow-up. This study highlights that conservative treatment should be attempted as first-line therapy in most patients with Yun's type III SISMAD. Complete AOR can contribute to remission of clinical symptoms during the acute stage. Poor distal blood flow of occluded vessels may serve as an important indicator for identification of patients at high risk of ischemic intestinal necrosis.

No Symptoms for Over 70 Years! Incidentally Discovered Congenital Dysplasia of Infrarenal Aorta

A 75 year old female with a past history of pulmonary embolism was admitted with dyspnoea. Computed tomography angiography unexpectedly revealed a significantly narrowed and completely occluded abdominal aorta at the infrarenal level. She did not have any intestinal or lower limb problems, but she had had resistant hypertension for 40 years. Bilateral femoral, popliteal, and pedal pulses were palpable. The superior mesenteric artery (violet arrow), the arc of Riolan (white arrows), and the inferior mesenteric artery (red arrow) were dilated, providing adequate blood flow to the abdomen, pelvis, and lower limbs.

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

BackgroundRecent 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.MethodsAfter 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.ResultsOn 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.ConclusionThis 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.

Endovascular aneurysm repair with mesenteric artery bypass for an abdominal aortic aneurysm with occlusion of celiac and superior mesenteric arteries

A 67-year-old male patient required surgical management of an abdominal aortic aneurysm. A contrast-enhanced computed tomography showed a saccular infrarenal abdominal aortic aneurysm, with occlusion of the origins of the celiac artery, superior mesenteric artery, and inferior mesenteric artery. An aortography revealed large amounts of blood flow from capillaries around the abdominal aorta to the inferior mesenteric artery and retrograde blood flow to the meandering mesenteric artery through the superior rectal artery. Considering the risk of bowel ischemia, we performed endovascular aneurysm repair with mesenteric artery bypass. The operation was successful, and the postoperative course was uneventful. This procedure may be useful and less invasive.

An Unusual Presentation of Congenital Megacolon with A Rare Vascular Anomaly: A Case Report

Congenital megacolon also referred to as Hirschsprung’s disease or aganglionic megacolon is characterized by the absence of nerve plexus in the colon, it rarely affects the small intestine. Whereas acquired megacolon is a constant dilatation of the large intestine in the absence of disease but occurs due to various factors such as infections, emotional disturbances, stress, or secondary to inflammatory bowel diseases (IBD) such as ulcerative colitis, Crohn’s disease, and proctocolitis. In the present case, we report here an unusual form of megacolon. The sigmoid colon was significantly enlarged but twisting or volvulus was not detected. The ascending, transverse, and remaining part of descending colon and mesentery appeared normal, The possibility of false rotation of the gut was excluded. Interestingly, the artery supplying the left one-third of the transverse colon and descending colon originated from a branch of the middle colic artery. This anomalous artery was found to form a communication with the trunk of the inferior mesenteric artery, the Arc of Riolan, and gave branches that supplied the descending colon. The left colic artery was absent. The transverse colon showed a stricture between its right 2/3rd and left 1/3rd, confirming with vascular accidents, resulting in anomalous blood supply and aganglionosis. The dilated part of the sigmoid colon was found to be with ganglion cells, while the distal part after the megacolon, lacked ganglion cells in all layers of the sigmoid colon. This case documents a very rare finding which will make the surgeons aware of a newer arterial pattern associated with congenital megacolon. KEYWORDS: Sigmoid colon, Hirschsprung’s disease, Arc of Riolan.

Midaortic syndrome and renovascular hypertension

Midaortic syndrome (MAS) is a rare condition characterized by stenosis of the abdominal aorta with or without the involvement of branch vessels. The majority of cases are thought to be idiopathic though MAS has been associated with a number of conditions including granulomatous vasculitis, neurofibromatosis-1 (NF-1), Alagille Syndrome, fibromuscular dysplasia (FMD), and Williams syndrome. Patients typically present with hypertension due to decreased renal perfusion. Less common presentations include renal insufficiency, heart failure, claudication, stroke, and abdominal pain. Imaging modalities help establish the diagnosis of MAS including duplex ultrasound, computed tomography angiography (CTA), magnetic resonance angiography (MRA), and angiography. Initial therapy focuses on medical management with antihypertensives prior to intervention. Invasive interventions are indicated when there is evidence of end organ damage or dysfunction such as decreased renal function, poorly growing kidneys, cerebrovascular accident, left ventricular hypertrophy or frank cardiac failure. Endovascular interventions may assist in diagnosis and may treat some lesions although reintervention rates are high. Most patients require some type of surgical intervention, and a variety of surgical options are available based on anatomic findings. Renal revascularization may be accomplished by renal artery bypass, autotransplantation, or renal artery reconstruction. Aortic lesions may be repaired using patch angioplasty or aortoaortic bypass. Mesenteric arteries do not typically require reconstruction as they are rarely symptomatic. More novel options include the use of tissue expanders to lengthen the aorta to allow for primary aortic reconstruction (TESLA) or the use of the meandering mesenteric artery as an autologous aortic bypass graft (MAGIC).

Inferior Mesenteric Artery Revascularization for Salvage of Mesenteric Ischemia

Often sacrificed in favor of the celiac and superior mesenteric arteries, the inferior mesenteric artery (IMA) can provide crucial inflow to the abdominopelvic viscera and spinal cord, especially in the presence of concomitant celiac or superior mesenteric artery (SMA) disease. We sought to elucidate the presentation and course of patients who had undergone IMA-specific revascularization. A retrospective analysis was performed of IMA revascularization procedures performed at an urban quaternary center from 2010 to 2020. Patients were included if concomitant renal artery, celiac artery, or SMA revascularization had been performed. Angioplasty, stenting, and open procedures were included. The patient characteristics, indications, and perioperative and long-term outcomes were analyzed. From 2010 to 2020, 10 patients had met the inclusion and exclusion criteria. Of the 10 patients, 9 were women (90%). Their median age was 71 years (range 47-88), and 80% had a history of smoking. Six patients had undergone elective IMA revascularization for chronic disease. Of the remaining four patients with acute symptoms, two had presented with an acute-on-chronic exacerbation of symptoms. All four patients with acute symptoms had presented as hospital transfers and had undergone intervention within 12 hours of transfer. However, two patients had had symptoms lasting >8 days before transfer. The 10 patients had undergone 16 procedures. Of the 10 patients, 8 had undergone IMA stenting, 1 had undergone percutaneous transluminal angioplasty alone, and 1 had undergone open IMA and aortic endarterectomy with patch angioplasty. Four patients had received concomitant celiac artery or SMA revascularization, with a large meandering mesenteric artery determining the choice to revascularize the IMA. In the six patients without celiac artery or SMA revascularization, three patients had had known SMA and celiac artery occlusions, and one had had a known occluded celiomesenteric trunk. In the four patients with acute symptoms, three small bowel resections and two laparotomies without bowel resection were performed. Six patients had required intensive care unit admission. Seven patients had had >1 year patency or had been lost to follow-up without known failure of IMA revascularization. Two patients died within 30 days with patent IMAs after withdrawal of care because of necrotic small bowel requiring resection. Two patients had undergone aortovisceral bypass after IMA occlusion—one patient on the day after IMA stenting and one patient at 17 months after IMA stenting. Revascularization of the IMA can serve as a reliable salvage option for patients with chronic or acute-on-chronic mesenteric ischemia, and should be considered for patients with high-grade stenosis or occlusion of the celiac artery and SMA.

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.

IntroductionThe 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.AimTo comprehend the presence and importance of the Moskowitz artery (meandering mesenteric artery) in preoperative patients by using computed tomography (CT) studies.Material and methodsWe 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.ResultsThere 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.ConclusionsKnowledge 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.

Endovascular Treatment of Mesenteric Ischaemia

Chronic mesenteric ischaemia constitutes a condition characterised by a decreased abdominal blood flow, which is caused by the obstruction of visceral arteries. This short communication paper presents a clinical case of endovascular treatment in a patient with the obstruction of the celiac trunk, superior and inferior mesenteric arteries. Intestinal blood supply was provided through collaterals from the system of internal iliac veins via the inferior mesenteric artery, the arc of Riolan. This clinical case confirmed that percutaneous transluminal angioplasty and stenting of the visceral arteries is the method of choice in the surgical treatment of abdominal angina.

04:12 PM Abstract No. 31 Predictive value of pre-procedural computed tomography angiogram on technical success of transarterial embolization of type II endoleaks arising from lumbar arteries

To evaluate the ability of pre-procedural CTA to predict the technical success of embolization of post-EVAR type II endoleaks arising from lumbar arteries. All patients at a single academic institution with post-EVAR type II endoleak from 2008-2018 were retrospectively reviewed. Patients without CTA were excluded. CTAs were reviewed for the ability to trace the entire course of vessels feeding the endoleak. Successful tracing was defined as identification of a feeding vessel from the internal iliac artery to the lumbar artery at the site of endoleak. Procedural imaging was reviewed for technical success, defined as catheterization of the lumbar artery at the site of endoleak. Sixty-eight patients with a type II endoleak underwent 75 transarterial interventions during the study period. Of these interventions, CTA prior to 57 angiograms (76%) showed a type II endoleak with a suspected feeding lumbar artery based on endoleak location along the posterior wall of the aorta. The supplying artery could be traced on prior CTA in 18 (32%) procedures, and embolization was technically successful in 16/18 (89%). In the remaining 39 (68%) procedures where the supplying artery could not be traced on prior CTA, the technical success rate was 10/39 (26%). The 31 endoleaks that were not treated via the iliolumbar artery branches were managed with embolization of the IMA origin through the Arc of Riolan (n=5), percutaneous aneurysm sac puncture (n=17), transcaval sac puncture (n=2), additional endograft placement (n=1), or active surveillance (n=6). A potential catheter path from the internal iliac artery through the iliolumbar and lumbar arteries to the aneurysm sac can be traced on CTA in the minority of lumbar-supplied type II endoleaks. The ability to trace these inflow vessels on preprocedural CTA is a reliable predictor of technical success during embolization. Low rates of technical success were identified when the feeding vessel could not be traced on CTA, suggesting these patients should be considered for a different approach such as percutaneous or transcaval aneurysm sac puncture.

Thrombectomy Devices in the Treatment of Acute Mesenteric Ischemia: Initial Single-Center Experience

To report our preliminary experience with endovascular revascularization of patients with acute mesenteric ischemia (AMI), using thrombectomy devices. It is a retrospective analysis of patients admitted to our hospital due to AMI and who were subjected to concomitant or exclusive endovascular treatment, from January 2011 to January 2016. Patients were admitted at the emergency department, underwent imaging investigation, and were referred to the endovascular specialist. Endovascular treatment was performed through left brachial artery access and selective catheterization and thrombectomy with a 6F Rotarex Debulking Device (Straub Medical, Wangs, Switzerland). Laparotomy was performed based on clinical and radiologic sings and at the discretion of the surgeon. Demographic, clinical/periprocedural, postoperative, complication, and adjunct intervention data were reviewed. Technical success was defined as recanalization of the Riolan's arcade on angiographic control. Twenty patients (mean age: 69.8±11.3years) underwent endovascular revascularization for AMI using thrombectomy devices, during the period of the study. Abdominal pain was the most common complain on admission (65%), with ileus (35%), sepsis (25%), and myocardial infarction as the main clinical referral presentation at admission. Fifteen patients (75%) had suggestive computer tomography (CT) signs of AMI on admission. Endovascular revascularization was successfully performed in all patients through the left brachial artery with a mean procedural time of 28±17min. Superior mesenteric artery (SMA) was the main vessel involved in 75% on a solely basis. The majority of the SMA occlusions were in the periosteal (30%) and proximal to middle colic artery offspring (35%). Primary use of thrombectomy devices was performed in all patients, associated with balloon angioplasty (7/20; 50%), stent deployment (5/20; 25%), intraoperative selective thrombolysis (4/20; 20%) and catheter-assisted aspiration in 10% (2/20) of patients. Average time between admission and computed tomography angiography was 1.5±0.5hr, between admission and angiographic procedure was 2.5±1hr, and between admission and surgery was 9±5hr. Following recanalization, 14 patients (70%) underwent open surgery. Laparotomy with intestinal resection (enterectomy, colectomy) and transit deviation was the most common procedure. Complications directly related to the endovascular procedure occurred in 2 patients, represented by self-limited small perforations. Overall 30-day mortality was 40% (n=8). During the period of this study, no patient died as a result of complications related to the use of rotational thrombectomy. Endovascular treatment of the AMI with the use of thrombectomy devices proved to be technically feasible and reasonably fast procedure. Early diagnosis and adequate treatment remains the cornerstone of the treatment. Early surgical evaluation and close integration between surgical and endovascular specialists are crucial to faster treatment and consequently lower extensive surgical resections and mortality. Further studies are necessary on this field to confirm these findings.

Congenital superior–inferior mesenteric arterial variation or arc of Riolan due to occlusion of proximal superior mesenteric artery

Congenital superior–inferior mesenteric arterial variation or arc of Riolan due to occlusion of proximal superior mesenteric artery

Branching pattern of inferior mesenteric artery in a black african population: a dissection study.

Background. Branching pattern of inferior mesenteric artery (IMA) and pattern of vascular supply to the left colon and rectosigmoid areas, though important during colorectal surgery, display interethnic variations. Further, these regions have notable vascular “weak points” reported to be highly susceptible to ischemic colitis. This study aimed at evaluating the branching pattern of IMA in a black African population. Materials and Methods. Fifty-seven formalin-embalmed cadavers (28 Male, 27 Female) were studied. The length, branching pattern, and diameter of IMA at its origin were recorded. Results. IMA mean length and diameter at origin were 30.57 ± 10.0 mm and 4.10 ± 0.9 mm, respectively. IMA most frequently branched into left colic artery and a common sigmoid trunk in 23 cases while the classical branching pattern was observed in only 7 cases. Colic marginal artery was absent at the splenic flexure and sigmoid colon in 7 and 5 cases, respectively. Arc of Riolan was observed in 9 cases. Conclusion. Branching pattern of IMA shows variations from the previously reported cases which might help account for some of the untoward outcomes observed following colon surgery. An angiographic study to further delineate functionality of the arterial anastomoses in this region is recommended.

Multimodality Imaging of Lower Extremity Peripheral Arterial Disease

Patients with symptomatic peripheral arterial disease (PAD) affecting the lower extremities are initially evaluated with an ankle-brachial index (ABI) and segmental pressure measurements. An ABI 50% stenosis) with a sensitivity and specificity of 79% and 96%, respectively.1 An ABI between 0.90 and 1.0 is considered borderline. The localization of the stenosis can be inferred by an abnormal decrease (>20 mm Hg) in segmental lower extremity pressures. In the presence of calcified atherosclerosis, arteries may become stiff and noncompressible, which results in a falsely elevated ABI (often >1.3). For patients with suspected PAD and a normal ABI at rest, it is valuable to obtain postexercise ABI measurements, which if <0.85 are consistent with PAD and is an independent predictor of mortality.2 Imaging is then needed to confirm the location and degree of stenosis before revascularization or if the diagnosis of PAD is uncertain. Characterization of PAD can be performed with noninvasive angiography using computed tomography (CTA) or magnetic resonance angiography (MRA), as well as with duplex ultrasonography (US), depending on patient specific characteristics (Table 1). Advances in both CTA and MRA provide clinicians with the opportunity to obtain a high resolution, 3-dimensional (3-D) road map of the peripheral arterial tree in patients, particularly when planning revascularization strategies. Invasive digital subtraction angiography (DSA) has been the accepted standard for evaluation of lower extremity atherosclerosis. Although DSA is a robust technique for diagnosing significant arterial stenosis or obstruction, it provides a 2-D view of the vessels, which may underestimate the degree of stenosis for tortuous vessels.3 Furthermore, there are inherent risks with arterial access, ionizing radiation, and the use of iodinated contrast media (CM).4 View this table: Table 1. Comparison Between CTA, MRA, and Duplex US for Diagnosis of PAD This review aims to deliver a comprehensive, yet concise …