Jejunal ischaemia following inferior mesenteric artery angioembolisation for type 2 endoleak.

We present a rare case of short-segment jejunal infarction following inferior mesenteric artery embolisation for type 2 endoleak in a patient who previously underwent endovascular repair of abdominal aortic aneurysm. Potential causes for the event might include thromboembolism or traumatic thrombosis of a jejunal branch of the superior mesenteric artery (SMA) caused by a buddy guide wire used to maintain the position of the long vascular sheath in the SMA hiatus. The condition was recognised on CT and treated with resection of the infarcted segment of the small bowel followed by primary anastomosis.

Variations in origin level of superior mesenteric artery, inferior mesenteric artery, and coeliac trunk in Indian population.

OBJECTIVE: The abdominal aorta is a continuation of the thoracic aorta and gives off the coeliac trunk, superior mesenteric artery, and inferior mesenteric artery. The focus of our study is to evaluate variations in the origin level in the coeliac trunk, superior mesenteric artery, inferior mesenteric artery, and aortic bifurcation in the Indian population and compare with various demographics. METHODS: The study was retrospective and the local ethics committee approval was taken before starting it. Three hundred patients who were more than 18 years of age and required contrast-enhanced CT studies were included in this. The vertebral origin level of the arteries from the abdominal aorta and aortic bifurcation level was analysed. RESULTS: The most common origin level of the coeliac trunk for both males and females was T12-L1 disc level. The most common origin level of the superior mesenteric artery was L1 upper level. The most common origin level of the inferior mesenteric artery was L3 upper level. The most common level of aortic bifurcation was L4 middle level. There was no statistical difference between the origin of any arteries in males and females in the Indian population. CONCLUSION: As per our study of the Indian population and the published literature, it is realized that there are significant variations in the origins of the coeliac trunk, superior mesenteric artery, inferior mesenteric artery, and abdominal aorta bifurcation in different populations. ADVANCES IN KNOWLEDGE: This study elaborates on potential anatomical variations in the Indian population, particularly the Mumbai city population. Also, our study compares it to different countries' data and their results in variations found in abdominal aorta branches.

Five-year follow-up of randomized clinical trial for pre-emptive inferior mesenteric artery embolization during endovascular aneurysm repair.

OBJECTIVE: Type II endoleak (T2EL) is the most common type of endoleak after endovascular aneurysm repair (EVAR) and a common indication for reintervention due to late sac enlargement. Although pre-emptive embolization of the inferior mesenteric artery (IMA) has been proposed to prevent this, no studies have prospectively demonstrated its efficacy. This study aimed to prove the validity of IMA embolization during EVAR in selective cases by analyzing the mid-term outcomes of a randomized clinical trial (RCT). METHODS: This single-center, parallel-group, non-blinded RCT included participants at high risk of T2EL, characterized by a patent IMA in conjunction with one or more following risk factors: a patent IMA ≥3 mm in diameter, lumbar arteries ≥2 mm in diameter, or an aortoiliac-type aneurysm. The participants were randomly assigned to two groups in a 1:1 ratio: one undergoing EVAR with IMA embolization and the other without. The primary endpoint was T2EL occurrence. The secondary endpoints included aneurysm sac changes and reintervention. In addition to RCT participants, outcomes of patients with low risk of T2EL were also analyzed. RESULTS: The embolization and non-embolization groups each contained 53 patients. Five-year follow-up after the last patient enrollment revealed that T2ELs occurred in 28.3% and 54.7% of patients in the IMA embolization and non-embolization groups, respectively (P = .006). Both freedom from T2EL-related sac enlargement ≥5 mm and cumulative incidence of sac shrinkage ≥5 mm were significantly higher in the IMA embolization group than in the non-embolization group (95.5% vs 73.6% at 5 years; P = .021; 54.2% vs 33.6% at 5 years; P = .039, respectively). The freedom from T2EL-related sac enlargement ≥10 mm, an alternative indicator for T2EL-related reintervention, showed similar results (100% vs 90.4% at 5 years; P = .019). Outcomes in the low-risk group were preferable than those in the non-embolization group and comparable to those in the IMA embolization group. CONCLUSIONS: A lower threshold for pre-emptive IMA embolization when implementing EVAR would be more appropriate if limited to patients at high risk of T2ELs.

Assessing anatomical variations of the inferior mesenteric artery via three-dimensional CT angiography and laparoscopic colorectal surgery: a retrospective observational study.

To assess the anatomy of the inferior mesenteric artery (IMA) and its branches by reviewing laparoscopic left-sided colorectal cancer surgery videos and comparing them with preoperative three-dimensional computed tomography (3D-CT) angiography, to verify the accuracy of 3D-CT vascular reconstruction techniques. High-definition surgical videos and preoperative imaging data of 200 patients who underwent laparoscopic left-sided colorectal cancer surgery were analysed, and the alignment of the IMA and its branches in relation to the inferior mesenteric vein (IMV) was observed and summarized. The above two methods were used to measure the length of the IMA and its branches. Of 200 patients, 47.0% had the sigmoid arteries (SAs) arise from the common trunk with the superior rectal artery (SRA), and 30.5% had the SAs arise from the common trunk with the left colic artery (LCA). In 3.5% of patients, the SAs arising from both the LCA and SRA. The LCA, SA, and SRA emanated from the same point in 13.5% of patients, and the LCA was absent in 5.5% of patients. The range of D cm (IMA length measured by intraoperative silk thread) and d cm (IMA length measured by 3D-CT vascular reconstruction) in all cases was 1.84-6.62 cm and 1.85-6.52 cm, respectively, and there was a significant difference between them. (p < 0.001). The lengths between the intersection of the LCA and IMV measured intraoperatively were 0.64-4.29 cm, 0.87-4.35 cm, 1.32-4.28 cm and 1.65-3.69 cm in types 1A, 1B, 1C, and 2, respectively, and there was no significant difference between the groups (p = 0.994). There was only a significant difference in the length of the IMA between the 3D-CT vascular reconstruction and intraoperative observation data, which can provide guidance to surgeons in preoperative preparation.

High Ligation of the Inferior Mesenteric Artery in Left-Sided Colon and Rectal Cancer Resection: Rates of Success and Outcomes.

BACKGROUND: High ligation of the inferior mesenteric artery, defined as ligation before the takeoff of the left colic artery, is often described as the gold standard in low left-sided colon and rectal cancer surgery. The aim of this study is to quantify the rate of ligation at the described level at a single academic center. Additionally, we examined the relationship between level of ligation and cancer-related outcomes. METHODS: This retrospective cohort study included patients ages 18 and over with low left-sided colon, rectal, and anal cancers undergoing surgical resection. Radiographic evidence of high ligation was defined as ligation of the inferior mesenteric artery before the takeoff of the left colic artery. Patients with and without radiographic evidence of high ligation on CT were compared. Secondary outcomes include lymph node yield and positivity, need for adjuvant therapy, and time from surgery to adjuvant therapy. RESULTS: 169 patients (54% male) were included in the study. 61.5% of operative reports described high ligation of the IMA. There was radiographic evidence of high ligation in 55.6% of total patients and in 70.2% of patients where high ligation was intended. There was no significant difference in surgeon experience, surgical procedure, or surgical approach. There was no difference in lymph node yield, time to adjuvant chemotherapy, or recurrence rates. CONCLUSION: This study demonstrates good technical success rate of high ligation of the inferior mesenteric artery but shows no difference in short-term patient-measured outcomes between high and low ligation (or successful and unsuccessful high ligation).

Reducing aneurysm sac growth and secondary interventions following endovascular abdominal aortic aneurysm repair by preemptive coil embolization of the inferior mesenteric artery and lumbar arteries.

OBJECTIVE: Type II endoleak (EL-2) is the most common complication following endovascular aneurysm repair (EVAR), leading to continued sac growth and potential rupture. In this study, we examined the association between patency of the inferior mesenteric artery (IMA) and lumbar arteries (LAs) with respect to sac growth. The effect of preemptive embolization of the IMA and/or LAs on the need for secondary interventions for sac growth post-EVAR was also evaluated. METHODS: A retrospective cohort study was performed on consecutive patients who underwent EVAR for non-ruptured, infrarenal abdominal aortic aneurysms (AAAs) from January 2012 to December 2020. A select group of patients underwent preemptive embolization of the IMA and/or LA. Patients with any types I, III, or IV endoleaks were excluded. Patency of the IMA and LA on preoperative computed tomography angiogram (CTA) was evaluated on TeraRecon workstation. All secondary interventions to treat EL-2 were recorded. Sac growth was defined as centerline axial diameter increase of ≥5 mm on follow-up CTA. RESULTS: A total of 300 patients (mean age, 74 ± 8.5 years; 83.7% male) underwent EVAR. Ninety-nine patients had preemptive embolization of the IMA and/or LA. Mean follow-up of the cohort was 59.3 ± 30.5 months. Thirty-six patients (12%) demonstrated sac growth on follow-up; 12 of these (33.3%) had preemptive embolization. The median time until detection of sac growth was 28.8 months (interquartile range, 15.2-46.5 months), with a mean growth of 10.1 ± 6.4 mm. Sac growth was significantly associated with presence of EL-2: 27 of 36 (75%) with EL-2 vs 9 of 36 (25%) without EL-2 (P < .001). Patients with sac growth had a higher mean total number (2.6 ± 1.5) of patent lower LAs (L3, L4) compared with those without (2.0 ± 1.4; P = .03). Patency of L1, L2, and L3 LAs were not associated with sac growth. However, patency of at least one L4 LA was significantly associated with sac growth (14.8% vs 7.7%; P = .04). The highest incidence of sac growth (17.6%) was seen when both IMA and L4 LA were patent; significantly different from the lowest incidence (5.3%) when both were occluded preoperatively (P = .018). Preemptive coiling of the IMA and/or LA significantly reduced the need for post-EVAR secondary intervention for sac growth. Freedom from post-EVAR secondary intervention was achieved in 92 of 99 (92.9%) pre-EVAR coiled patients vs 163 of 201 (81.5%) patients who did not undergo pre-EVAR coiling (P = .009). CONCLUSIONS: Preemptive coil embolization of the IMA and LAs, especially L4 LA, reduces the need for secondary interventions for sac growth, potentially improving the long-term durability of EVAR.

Laparoscopic surgery for rectal cancer with a coexisting Retzius shunt and inferior mesenteric arteriovenous malformation: A case report.

A coexisting short-circuit from the inferior mesenteric vein (IMV) to the inferior vena cava, known as a Retzius shunt, and arteriovenous malformation (AVM) of the inferior mesentery are extremely rare conditions. We encountered a case of rectal cancer with coexisting Retzius shunt and inferior mesenteric AVM successfully treated with laparoscopic surgery. Contrast computed tomography (CT) in a 62-year-old man with rectal cancer showed multiple dilated veins at the mesenterium of the descending sigmoid colon. These dilated veins were connected between the IMV and the left renal vein. A diagnosis of Retzius shunt was made, and laparoscopic low anterior resection with lymph node dissection was performed. A pathological examination of the colonic mesenterium revealed AVM communicating with the dilated IMV and Retzius shunt. The preoperative evaluation of aberrant vessels by three-dimensional CT is particularly useful for patients with vascular malformations to ensure safe laparoscopic surgery.

A rare case of unconnection between the celiac trunk and the abdominal aorta and a large anastomosis with the inferior mesenteric artery with a literature review.

PURPOSE: Direct connection between the celiac trunk (CT) and inferior mesenteric artery (IMA) is very rare, knowledge of this anomaly is of great importance to surgeons and anatomists. INTRODUCTION: Splanchnic arteries arise from the abdominal aorta (AA). Unusual development of these arteries can lead to considerable variations. Historically there were a lot of classification of the variation in the CT and IMA, none of the classifications describes a direct connection from IMA to CT. MATERIALS AND METHODS: We report a rare case in which the connection between the CT and AA was lost and replaced by a direct anastomosis with IMA. RESULTS: 60 year old male presented to the hospital to undergo a computed tomography scan. Which showed that there was no CT arising from the AA, but there was a large anastomosis arises from the IMA and ended with a short axis and Left gastric artery (LGA), Splenic artery (SA), Common hepatic artery (CHA) arise from this axis, these arteries continued to the stomach and spleen and liver normally. The anastomosis provides the total supply to the CT. The CT branches are normal. CONCLUSION: Knowledge of the arterial anomalies provides an important help in clinical surgical implications especially in organs transplant.

Inferior mesenteric artery arteriovenous malformation, a rare cause of ischemic colitis: A case report.

RATIONALE: An arteriovenous malformation (AVM) is an abnormal tangle of blood vessels that connects the arteries and the veins. Because normal capillary bed is partially or completely absented in the AVM, the blood passes quickly from the arteries to the veins, which disrupts normal blood flow and oxygen supply to the surrounding tissues. This is called "steal phenomenon," and in the inferior mesenteric artery (IMA) territory, this may lead to abdominal pain, gastrointestinal bleeding, portal hypertension, and even ischemic colitis. PATIENT CONCERNS: A 67-year-old man presented to our emergency department because of left side abdominal pain. DIAGNOSES: The abdominal computed tomography with contrast enhancement revealed a cluster of abnormal vascular lesions abutting the IMA with early opacification of the left colonic marginal vein. In addition, poor enhancement of segmental colonic wall was found from proximal descending colon to middle rectum. The diagnosis of AVM of the IMA and ischemic colitis was made. INTERVENTIONS: The patient underwent left hemicolectomy as well as the AVM resection. OUTCOMES: He was discharged uneventfully after the surgery without complications. LESSONS: IMA AVM carries the risk of ischemic colitis. computed tomography scan is helpful not only to the diagnosis of AVMs but also to exclude other lesions as well. Treatment options include endovascular embolization, surgical intervention, and a combination of both. Due to the complexity of this disease, treatment requires a case-specific multidisciplinary approach and a coordination of medical, radiological, and surgical staffs.

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.

Routine Inferior Mesenteric Artery Embolisation is Unnecessary Before Endovascular Aneurysm Repair.

OBJECTIVE: A type II endoleak is the most common complication during surveillance after endovascular aneurysm repair (EVAR), and a patent inferior mesenteric artery (IMA) is a known risk factor for an endoleak. The effect of routine IMA embolisation prior to EVAR on overall outcome is unknown. The aim of the study was to compare two strategies: routine attempted IMA embolisation prior to EVAR (strategy in centre A) and leaving the IMA untouched (strategy in centre B). METHODS: Patients were treated with EVAR in two centres during the period 2005 - 2015, and the data were reviewed retrospectively. The primary endpoints were re-intervention rate due to type II endoleaks and the late IMA embolisation rate. Secondary endpoints included EVAR related re-intervention, sac enlargement, aneurysm rupture, and open conversion rates. RESULTS: Strategy A was used to treat 395 patients. The IMA was patent in 268 (67.8%) patients, and embolisation was performed in 164 (41.5%). The corresponding figures for strategy B were 337 patients with 279 (82.8%) patent IMAs, two (0.6%) of which were embolised. The mean duration of follow up was 70 months for strategy A and 68.2 months for strategy B. The re-intervention rates due to a type II endoleak were 12.9% and 10.4%, respectively (p = .29), with no significant difference in the rate of re-interventions to occlude a patent IMA (2.0% and 4.7%, respectively; p = .039). The EVAR related re-intervention rate was similar, regardless of strategy (24.1% and 24.6%, respectively; p = .93). Significant sac enlargement was seen in 20.3% of cases treated with strategy A and in 19.6% treated with strategy B (p = .82). The rupture and conversion rates were 2.5% and 2.1% (p = .69) and 1.0% and 1.5% (p = .40), respectively. CONCLUSION: The strategy of routinely embolising the IMA does not seem to yield any significant clinical benefit and should therefore be abandoned.

Delayed bowel necrosis due to inferior mesenteric artery occlusion in Stanford type A acute aortic dissection.

Although inferior mesenteric artery occlusion due to acute aortic dissection sometimes occurs, it is usually not considered an important finding. Herein, we present an extremely rare case of delayed bowel ischaemia due to inferior mesenteric artery occlusion in Stanford type A acute aortic dissection that highlights the need for cardiac surgeons to be mindful of inferior mesenteric artery occlusion in patients with superior mesenteric artery dissection or vascular anomalies in the mesenteric arteries.

[Surgeon's role in CT-based preoperative determination of inferior mesenteric artery anatomy in colorectal cancer treatment]. / Rol' khirurga v opredelenii anatomii nizhnei bryzheechnoi arterii po dannym komp'yuternoi tomografii pri lechenii kolorektal'nogo raka.

BACKGROUND: The inferior mesenteric artery (IMA) is a blood vessel of great importance in left colon and rectal cancer surgery. We aimed to determine the role of surgeons in computed tomography (CT) based vascular anatomy interpretation. METHOD: Patients with left colon and rectal cancer treated surgically with D3 lymph node dissection and selective vascular ligation were included in this study. All patients (n=250) underwent preoperative CT with intravenous contrast. The IMA anatomy was schematically depicted by surgeon based on CT interpretation. Intraoperatively anatomy was defined by skeletonisation of the IMA. All patients had segmental resection with selective vascular ligation. The concurrence of prospectively obtained results were evaluated by intraclass correlation and Kendall's tau-b test. Misinterpretation of IMA anatomy was analysed by CT-specialist. RESULTS: The preoperative and intraoperative IMA anatomy features were correctly interpreted in 237 cases (in 94.8%) within skeletonisation extent, which is supported by high level of agreement and concordance of preoperative data regards to intraoperative findings (K=0.926; p<0.001; CC=0.912; p<0.001). As a result of the CT-based evaluation of the IMA, E, K, and H types of branching patterns were proposed. IMV position was mistakenly identified in 2.6% of cases. CONCLUSION: Surgeons are able to evaluate the IMA anatomy accurately with CT and use it in routine preoperative planning. The E, K, and H branching types may be used when defining approach to skeletonisation and level of vascular ligation.

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.

Inferior mesenteric artery diameter and number of patent lumbar arteries as factors associated with significant type 2 endoleak after infrarenal endovascular aneurysm repair.

OBJECTIVES: Our goal was to identify the inferior mesenteric artery diameter and number of patent lumbar arteries causing a significant type 2 endoleak to develop after infrarenal endovascular aneurysm repair. MATERIAL AND METHODS: Included were patients who underwent infrarenal endovascular aneurysm repair between April 2002 and January 2017. Patients with an aneurysm involving the iliac arteries were excluded. Significant type 2 endoleak was defined as a type 2 endoleak observed after infrarenal endovascular aneurysm repair and accompanied by abdominal aneurysm growth of at least 5 mm during that time. RESULTS: A total of 277 patients were included. Mean follow-up was 38.9 (standard deviation 121.6) months. Immediately after infrarenal endovascular aneurysm repair, type 2 endoleaks occurred in 55 patients (20%), resolving spontaneously in 2 patients 6 months after infrarenal endovascular aneurysm repair. Thirty (10.8%) patients revealed a significant type 2 endoleak with aneurysm sack enlargement > 5 mm during follow-up, for which inferior mesenteric artery or lumbar artery coiling was performed. Mean time for coiling after primary infrarenal endovascular aneurysm repair was 25.4 (standard deviation 19.10) months. Twenty-three patients (8.3%) showed a non-significant type 2 endoleak during follow-up (no aneurysm sack enlargement). We found that the inferior mesenteric artery diameter and number of patent lumbar arteries were factors associated with a significant type 2 endoleak (odds ratio 1.755, P = 0.001; odds ratio 1.717, P < 0.001, respectively). Prior to endovascular aneurysm repair, the inferior mesenteric artery was patent in 212 (76.5%) patients; its median diameter measured 3 (0.5-3.8) mm. The median number of patent lumbar arteries was 3 (2-4). According to our receiver operating characteristic curve analysis, an inferior mesenteric artery diameter ≥3 mm (sensitivity 93.3%, specificity 65%) and ≥3 patent lumbar arteries (sensitivity 87.5%, specificity 43.6%) proved to be optimal cut-off values related to developing a significant type 2 endoleak. We therefore propose a composite score for the development of a significant type 2 endoleak [(inferior mesenteric artery diameter + patent lumbar arteries)/2]. CONCLUSIONS: Patients in whom the diameter of the inferior mesenteric artery is ≥ 3 mm and with ≥ 3 patent lumbar arteries carry a higher risk of developing significant type 2 endoleak after infrarenal endovascular aneurysm repair.