Variations In Vascular Anatomy Research Articles

Hepatic Artery Thrombosis After Liver Transplantation: Five-Year Experience at the State University of Campinas

BackgroundHepatic artery thrombosis (HAT) is reported in 4%-15% of orthotopic liver transplants. Risk factors include technical error in the anastomosis, vascular anatomic variation, and high microvascular resistance. The aim of this study was to verify the incidence of HAT, early or late, and possible risk factors. MethodsThis was a retrospective study from January 2007 to December 2012 at the State University of Campinas. Variables analyzed were age, sex, cold and warm ischemia times, underlying disease, presence of hepatocellular carcinoma, Model for End-Stage Liver Disease (MELD) score, arterial anatomic variation in the graft, cytomegalovirus (CMV) infection, rejection, biliary complications, retransplantation rate, and survival. ResultsThe incidence of HAT was 21/263, or 7.9%. Pure average MELD score was 22 ± 7.4. There was vascular anatomic variation in the graft in 14.2% of cases, in the majority (66.6%) a right hepatic artery from the superior mesenteric artery, and 4.76% of patients had CMV infection and acute cellular rejection (1 case each). There were biliary complications in 38% of patients, 13.3% of cases in patients with early HAT, and 100% of patients with late HAT (P = .002). Body mass index in late HAT was higher (P = .01). ConclusionsLate HAT was related to a significant increase in biliary complications (stenosis), and the survival rate was similar at 5 years.

The Radiological Scrutiny of the Relation between Renal Vascular Dimensions and Anatomical Variation of Renal Arteries: The Must to Know before Renal Transplantation

Renal transplantation is the preferred treatment of patients suffering from end stage renal disease. Because of challenges in performing surgical vascular anastomosis in variant renal anatomy, knowledge on renal vascular anatomy is very important in the pre surgical workup of potential kidney donors. These anatomical variations differ geographically and ethnically. In Kenya there has been scanty statistics on prevalence of extra-renal branching of arteries but also the clear knowledge in the understanding of the relation between renal sizes, their main arterial diameters in predicting the presence of accessory arteries without invasive diagnostic methods. This study was designed to add into the body of literature more information about the dimensions of renal vascular anatomy of adult African population in Kenya and transmit this knowledge to enrich the renal surgery practice in the region and beyond. Therefore the aim of this study was to determining the relationship between kidney size, main renal arterial caliber and how they relate in the presence or absence of accessory arteries. The study was a three-year crosssectional descriptive study conducted at Kenyatta National Hospital from June 2008 to June 2011. A total of 204 cases including 103 (50.5%) females and 101 (49.5%) males were recruited for CTA. Most normal sized kidneys with accessory arteries had smaller main renal arterial diameters. Extra renal branching occurred in 14.7% of cases. It is concluded that the presence of accessory arteries cannot be determined by the study of kidney sizes alone. The current value of Renal CTA cannot be easily replaced by simplified noninvasive modalities for indirect and accurate study of renal vascular anatomy of potential kidney donors.

Free anteromedial thigh perforator flap: Complementing and completing the anterolateral thigh flap.

Objective:Theobjective of this study was to determine the indications, utility, advantages and surgical approach for the anteromedial thigh (AMT) flap.Materials and Methods:We reviewed the records of the patients in whom the AMT flap was used for head and neck reconstruction. We use an anterior approach to harvest the anterolateral thigh (ALT) flap with a non-committal straight line incision. This preserves both ALT and AMT flap territories intact, and further decision is based on the intraoperative anatomy of perforator and pedicle. The ALT flap was usually used as the first choice when available and suitable.Results:Free AMT skin flaps were harvested in 24 patients. All flaps were used for the head and neck reconstruction. Two flaps had marginal flap necrosis. One flap was lost due to venous thrombosis.Discussion:The thigh is an excellent donor site as it has large available skin territory, expendable lateral circumflex femoral artery system and low donorsite morbidity. The ALT flap is the most commonly used flap for reconstruction of soft-tissue defects. However, it is characterised by variable vascular pedicle and perforator anatomy. The AMT flap is an excellent alternative when the ALT flap is not available due to variable perforator anatomy, injury to perforator, when an intermediate thickness is needed between distal and proximal thigh or a chimeric flap is needed.Conclusion:The AMT flap offers all the advantages of the ALT flap without increasing donor-site morbidity. The anterior non-committal approach keeps both the ALT and the AMT flap options viable.

Vascular Complications Following Liver Transplantation

Patients who have undergone liver transplantation can experience a variety of vascular complications that must be recognized early and treated in a timely manner to preserve graft function. To accomplish this, radiologists must be familiar with the variable vascular anatomy and surgical techniques, recognize signs of vascular pathology, and suggest the most appropriate treatment. This article discusses these topics, providing reference diagrams with graphic and radiologic example cases.

A reappraisal of the surgical planning of the superficial circumflex iliac artery perforator flap

The popularity of the superficial circumflex iliac artery perforator (SCIP) flap has been limited by factors such as variable vascular anatomy and short arterial pedicle. This article aimed to delineate flap design and harvest strategies based around either the proximal or distal perforators of the superficial circumflex iliac artery (SCIA) and propose a set of strategies that can help deal with the limitations of the flap. From August 2011 to June 2015, the SCIP flap was used in 80 patients for soft tissue defects at our institution. We utilized vessel imaging navigation to get a detailed overview of the vascular anatomy preoperatively. Flaps were designed on the basis of either the proximal or distal perforators of the SCIA. Backup strategies and surgical maneuvers were suggested to solve the problems that emerged during surgery. In total, 51 flaps were raised on the basis of the proximal perforators of the superficial branch of the SCIA, whereas 25 cases were based on the distal perforators from the deep branch, and in four cases, the pedicle was switched to the superficial inferior epigastric artery. In eight cases, the arterial pedicle lengthen technique was applied with a maximum length of 10cm. All donor sites were closed directly with inconspicuous scars. These surgical strategies simplified the intraoperative decision-making and overcame the shortcomings of the SCIP flap. We believe that the SCIP flap has a great potential to become a new workhorse flap in the field of reconstructive surgery.

Unusual Pancreatico-Mesenteric Vasculature: A Clinical Insight

Background: Awareness about the variable vascular anatomy of superior mesenteric artery is imperative for appropriate clinical management. Present study not only augments anatomical literature pertaining to mesenteric vasculature but also adds to the clinical acumen of medical practitioners in their clinical endeavors.

Septal Atrioventricular Junction Region: Comprehensive Imaging in Adults.

The septal atrioventricular junction is a centrally located region of the heart where the septal components of the atria and ventricles meet the aortic, mitral, and tricuspid valves. Important structures in this region include the membranous septum, the central fibrous body, the Koch triangle, the inferior pyramidal space, and the base of the interventricular septum. This small area is the home of the atrioventricular node and the atrioventricular conduction axis and has enormous importance to electrophysiologists owing to its prime role in the conduction system of the heart. The atrioventricular node lies within the triangle of Koch; and the atrioventricular bundle, or bundle of His, exits the atrioventricular node and penetrates the right fibrous trigone and runs underneath the membranous septum. The septal atrioventricular junction is a common location for intracardiac shunts such as membranous and perimembranous septal defects. Imaging classification of these defects can have important implications before surgical closure, because the atrioventricular conduction axis passes along the posteroinferior margin of most perimembranous defects. Extracardiac inflammatory and malignant pathologic conditions can extend from the mediastinum toward the inferior pyramidal space in this region through the epicardial fat planes. Although the anatomic structures are complicated, the components can be shown in exquisite detail with computed tomography (CT). In this review, the anatomic boundaries and important anatomic landmarks are examined with CT and magnetic resonance imaging. Also described are the anatomic variants of the membranous septum pertinent to percutaneous aortic valve implantation, the vascular anatomic variants, and commonly encountered pathologic conditions related to the septal atrioventricular junction. ©RSNA, 2016.

T-microstent-assisted coiling in the management of ruptured wide-necked anterior communicating artery aneurysms: Choosing between Y, X and T

Anterior communicating artery aneurysms frequently present wide necks and incorporate parent vessels. They are associated with significant variations in vascular anatomy, especially hypoplasia or aplasia of one of the proximal anterior cerebral arteries. Safe and complete endovascular occlusion of these aneurysms usually requires the assistance of complex approaches including dual stenting. We describe a technique for T-configured stent-assisted coiling in the management of ruptured wide-necked AcomA aneurysms by means of two simultaneous microsystems that allowed placement of two nitinol self-expandable Leo+ Baby stents (Balt Therapeutics, Montmorency, France) followed by coiling. Technical details and comparison to other dual stent configurations were presented and briefly discussed.

Simultaneous CT angiography and whole-body CT is an effective imaging approach before multiorgan retrieval

To assess the role of whole-body computed tomography (CT) for determining morphological suitability before multiorgan retrieval (MOR) in brain dead patients. Fifty-one clinically brain dead patients (21 women, 30 men; mean age 61 year±15) were included in this prospective, single center study. All patients had CT angiography of the brain and whole-body CT examination. CT images were evaluated for the presence of morphological abnormalities of lungs, liver and other abdominal organs and presence of vascular anatomical variants. The results of CT examinations were compared to intraoperative findings observed during organ harvesting and/or the results of histopathological analysis of biopsy specimens. The impact of whole-body CT examination on the harvesting process was evaluated. Ninety-five percent of vascular anatomical variants that were found intraoperatively were depicted on CT. CT density measurements predicted surgical finding of steatosis in 80% of patients. Whole-body CT changed the MOR strategy in 21/51 patients (41%) including 3 MOR cancellations and 8 grafts refusals, whereas organ harvesting was continued in 10 patients after histopathological analysis was performed. Selection of potential graft donors using whole-body CT is reliable and improves graft selection during MOR.

Vascular Anatomy in Laparoscopic Colectomy for Right Colon Cancer.

The vascular anatomy in the right colon varies; however, related studies are rare, especially on the laparoscopic vascular anatomy of living patients. The purpose of this study was to describe vascular variations around the gastrocolic trunk, middle colic vein, and ileocolic vessels in laparoscopic surgery for right-sided colon cancer. This is a retrospective descriptive study of patients undergoing laparoscopic colectomy for right colon cancer. The study was conducted at a single tertiary institution in Korea. Consecutive patients with right colon cancer who underwent laparoscopic right colectomy using the cranial-to-caudal approach (N = 116) between January 2014 and April 2015 were included. Three colorectal surgeons took photographs and videos of the vascular anatomy during each laparoscopic right colectomy, and these were analyzed for vascular variations. We classified venous variations around the gastrocolic trunk into 2 types (3 subtypes), type 1 (n = 92 (79.3%)), defined as 1 or 2 colic veins draining into the gastrocolic trunk, and type II (n = 24 (20.7%)), defined as having no gastrocolic trunk. We also investigated the tributaries of the superior mesenteric vein. One, 2, and 3 middle colic veins were found in 86 (74.1%), 26 (22.4%), and 4 patients (3.5%). The right colic vein drained directly into the superior mesenteric vein in 22 patients (19.0%). All of the patients had a single ileocolic vein draining into the superior mesenteric vein and a single ileocolic artery from the superior mesenteric artery. The right colic artery from the superior mesenteric artery was present in 38 patients (32.7%). The ileocolic artery passed the superior mesenteric vein anteriorly or posteriorly in 58 patients (50%) each. Unlike cadaver or radiological studies, we could not clarify the complete vessel paths. We classified vascular anatomic variations in laparoscopic colectomy for right colon cancer, which could be helpful for colorectal surgeons.

Liver Findings in Patients with Hereditary Hemorrhagic Telangiectasia.

BackgroundHereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome, is a rare autosomal dominant genetic vascular dysplasia.ObjectivesThe aim is to characterize the liver involvement of HHT by multi-detector helical computed tomography.Patients and MethodsThrough the use of multi-detector helical computed tomography, scan data derived from 12 cases of HHT were retrospectively studied, and an abdominal scan was performed on all of the patients.Results(i) Three types of shunting were found in the livers, including arteriovenous (hepatic artery to hepatic vein) in 6 cases, arterioportal (hepatic artery to portal vein) in 2 cases, and portal venous (portal vein to hepatic vein) in 4 cases, (ii) Biliary diseases were detected in 8 cases, including 3 cases of bilomas accompanied by increases of alkaline phosphatase (mean 271 units, ranging from 152 to 479 units) and arteriovenous shunts, and the other 5 cases revealed slight biliary dilation with no increase of alkaline phosphates, but were instead accompanied by arteriovenous shunts (3 cases) and portal venous shunts (2 cases). (iii) Vascular anatomic variants were observed in 4 cases, including 3 with accompanying arteriovenous shunts and 1 with accompanying arterioportal shunting.ConclusionThe involved liver with HHT typically shows vascular shunting and biliary diseases. Also, arteriovenous shunts may be vulnerable to biliary diseases.

Unilateral fetal-type circle of Willis anatomy causes right–left asymmetry in cerebral blood flow with pseudo-continuous arterial spin labeling: A limitation of arterial spin labeling-based cerebral blood flow measurements?

The accuracy of cerebral blood flow measurements using pseudo-continuous arterial spin labeling can be affected by vascular factors other than cerebral blood flow, such as flow velocity and arterial transit time. We aimed to elucidate the effects of common variations in vascular anatomy of the circle of Willis on pseudo-continuous arterial spin labeling signal. In addition, we investigated whether possible differences in pseudo-continuous arterial spin labeling signal could be mediated by differences in flow velocities. Two hundred and three elderly participants underwent magnetic resonance angiography of the circle of Willis and pseudo-continuous arterial spin labeling scans. Mean pseudo-continuous arterial spin labeling-cerebral blood flow signal was calculated for the gray matter of the main cerebral flow territories. Mean cerebellar gray matter pseudo-continuous arterial spin labeling-cerebral blood flow was significantly lower in subjects having a posterior fetal circle of Willis variant with an absent P1 segment. The posterior fetal circle of Willis variants also showed a significantly higher pseudo-continuous arterial spin labeling-cerebral blood flow signal in the ipsilateral flow territory of the posterior cerebral artery. Flow velocity in the basilar artery was significantly lower in these posterior fetal circle of Willis variants. This study indicates that pseudo-continuous arterial spin labeling measurements underestimate cerebral blood flow in the posterior flow territories and cerebellum of subjects with a highly prevalent variation in circle of Willis morphology. Additionally, our data suggest that this effect is mediated by concomitant differences in flow velocity between the supplying arteries.

Reseach development of vascular anatomy and preoperative design technology of anterolateral thigh flap

?To summarize the present status and progress of vascular anatomy and preoperative design technology of the anterolateral thigh flap. ?The relative researches focused on vascular anatomy and preoperative design technology of the anterolateral thigh flap were extensively reviewed, analyzed, and summarized. ?Vascular anatomy of the anterolateral thigh flap has been reported by numerous researchers, but perforators' location, origin, course, and the variation of the quantity have been emphasized. Meanwhile, the variation of descending branch, oblique branch, and lateral circumflex femoral artery has also been widely reported. Preoperative design technology of the anterolateral thigh flap includes hand-held Doppler, Color Doppler, CT angiography (CTA), magnetic resonance angiography, digital subtraction angiography, and digital technology, among which the hand-held Doppler is most widely used, and CTA is the most ideal, but each method has its own advantages and disadvantages. ?There is multiple variation of vascular anatomy of the anterolateral thigh flap. Though all kinds of preoperative design technologies can offer strong support to operation of anterolateral thigh flap, a simple, quick, precise, and noninvasive technology is the direction of further research.

WIDEFIELD FLUORESCEIN ANGIOGRAPHY IN PATIENTS WITHOUT PERIPHERAL DISEASE: A Study of Normal Peripheral Findings.

Widefield photography and angiography provide access up to 200-degrees of the retinal periphery. The range of normal peripheral findings has not been characterized, yet is relevant to studies addressing putative peripheral retinal vascular pathology. This study was an observational retrospective cohort study. Adult patients with epiretinal membrane or choroidal nevi who underwent imaging with Optos 200 MA/200Tx were included. Dye transit times, peripheral arteriovenous shunting, presence of vessels crossing the horizontal raphe, right angle vessels, terminal networks, absence of capillary detail, ground glass hyperfluorescence, peripheral drusen, and microaneurysms were evaluated. Fifty-eight eyes of 31 patients met inclusion criteria. Mean peripheral arterial filling time was 8.65 ± 2.54 seconds (range 3-15 seconds). One or more peripheral anomalies were noted in all patients (P < 0.01). The prevalences of findings were: arteriovenous shunting (0.00%), vessels crossing the horizontal raphe (44.83%), right angle vessels (70.69%), terminal networks (77.59%), absence of capillary detail (98.28%), ground glass hyperfluorescence (87.93%), drusen (34.48%), and microaneurysms (41.38%). There was a high prevalence of peripheral vascular anatomic variations in eyes expected to have normal peripheral retinal vasculature. These findings may provide a reference for future studies addressing putative pathologic peripheral angiographic findings.

Multiphase whole-body CT angiography before multiorgan retrieval in clinically brain dead patients: Role and influence on clinical practice.

To evaluate the contribution of multiphase whole-body CT angiography (CTA) for identifying the contra-indications to multiorgan retrieval (MOR) and improving the preoperative organ harvesting strategy. One hundred and eleven consecutive patients who were clinically brain dead underwent multiphase whole-body CTA to confirm the diagnosis of brain death and for assessment of MOR. The CTA protocol included volumetric acquisitions of the brain and abdominopelvic cavity without IV administration of iodinated contrast material, then images of the thorax-abdomen-pelvis 25s after IV contrast administration, of the brain at 60s and finally an abdominopelvic CT acquisition at 90s. The diagnosis of brain death was based on well-established criteria. The assessment of thorax, abdomen and pelvis was based on a systematic checklist. Post-processing imaging techniques were used in all patients. No organs were retrieved from 21patients due to patient refusal (19%). Twenty-two potential MOR were denied because of general contra-indications including 12/22 (54%) based on CTA criteria alone. Finally, 68patients were eligible for MOR and 160organs were harvested. The exclusion of specific organs was based on CTA alone for 2/16 livers, 4/70 kidneys and 5/55 lungs. Fifty hearts and 58 pancreases were not harvested, none based on CTA results alone. Hepatic abnormalities and vascular anatomical variants were identified in 10% of patients. At least one renal artery variant was found in 28% of patients, 13% presented with a double renal vein and 8% with a hepato-mesenteric artery. Multiphase whole-body CTA for MOR is based on the simultaneous association of cerebral CTA to determine brain death with CTA of the thorax, abdomen and pelvis. This rapid, standardized and easily accessible procedure has no harmful effects on harvested kidneys. It makes it possible to select the donors and the organs to be harvested and allows the retrieving surgeon to identify and anticipate technical difficulties.

Cerebrovascular and Brain Abnormalities in Autosomal- Dominant Polycystic Kidney Disease: Role of 3d Time-of-Flight Magnetic Resonance Angiography

Introduction: The association of intracranial aneurysms and autosomal-dominant polycystic kidney disease (ADPKD) is well recognized. The aim of this study was to assess the prevalence of asymptomatic intracranial aneurysms and to verify the presence of other cerebral abnormalities in patients with ADPKD by Magnetic Resonance Angiography screening. Materials and methods: From January 2009 to September 2013, 56 patients with ADPKD (25 M, 31 F; mean age 40 years, range 24- 63 years) underwent brain Magnetic Resonance Imaging including 3D time-of-flight MR angiography and T2-weighted Turbo-Spin-Echo axial sequences. Magnetic Resonance studies were examined by two experienced neuroradiologists (20 years). If an intracranial aneurysm was detected, cerebral Computed Tomography Angiography was recommended and further action were discussed with the interventional neuroradiologist. Results: Nine saccular intracranial aneurysms were detected in 56 patients, located in the anterior circulation (5 internal carotid arteries, 1 anterior communicating artery and 3 middle cerebral arteries). Four patients underwent endovascular treatment with flow-diverter devices. We additionally found internal carotid artery abnormal diameter and course (6), basilar artery hypoplasia (1), basilar artery dolichoectasia (1), asymmetric anterior cerebral (4) and vertebral (14) arteries, vascular anatomic variants (3), venous drainage anomaly (1), arachnoid cysts (6), large bilateral choroid plexus cysts (1) and mega cisterna magna (2). Conclusions: The prevalence of asymptomatic intracranial aneurysms (16.1%), higher compared to the general population (1%) and similar to literature reports in autosomal dominant polycystic kidney disease (6-16%), confirmed the importance of the Magnetic Resonance Angiography screening in these patients.

Clinical importance of congenital anomalies of the inferior vena cava in organ procurement surgery from a deceased donor: two case reports

Congenital anomalies of the inferior vena cava (IVC) are rare but important problems in living donors for kidney transplantation, especially in cases of a short left renal vein and accompanying vascular and urological anatomic variations. However, the clinical impacts of IVC anomalies in deceased donors have yet to be reported. The unexpected presence of an IVC in an unusual position poses challenges to surgeons and increases the risk of bleeding during organ removal. Accompanying vascular variations can cause unexpected bleeding and injury and therefore technical complications in procurement and subsequent implantation. During cold perfusion, inadequate venous drainage or insufficient cooling can induce graft damage. Our cases highlight the need for all transplant surgeons to confirm the anatomy of the aorta, IVC, and major vessels early in the surgical procedure and, should an anomaly be detected, know how to manage the problem.

The Artery of Adamkiewicz: Vascular Anatomy, Clinical Significance and Surgical Considerations

The artery of Adamkiewicz is the only major arterial supply feeding the anterior spinal artery along the lower thoracic, lumbar and sacral spinal cord. This vessel is clinically significant as injury to this vital artery can occur during a variety of procedures, most notably descending/thoracoabdominal aortic repairs. Injury to this artery can cause consequential neurologic damage manifesting as anterior spinal cord syndrome. New research on this topic has supported preoperative identification of the artery of Adamkiewicz prior to thoracic surgery as a means to protect the spinal cord. Numerous radiological imaging techniques, such as digital subtraction angiography, magnetic resonance angiography, and three dimensional reconstruction using computer tomography angiography, have been implemented to localize this vessel prior to surgery, each with their own strengths and weaknesses. Here, we review the variable vascular anatomy supplying the spinal cord, clinical significance of the artery of Adamkiewicz, as well as examine the various radiological imaging techniques currently used to visualize this vessel prior to surgery.

The Use of Gastrocnemius Muscle Flap in Reconstruction of Pretibial Defects

Background: In Western part of Nepal the post traumatic lower leg and bone injuries with infected, open wound is common occurrence.Aim: It was to find out whether Gastrocnemius muscle flap is a viable option for pretibial defects. However variations in vascular anatomy of pedicle, use of reverse flow soleus muscle flap based on posterior tibial artery, leads to high failure rate and sacrificing major leg vessels.Method: Use of soleus muscle flap supported by perforating arteries, branches of posterior tibial vessels is option to cover small defects. The flap with careful newer modification to preserve vascularity, is used in 32 cases of pretibial defects.Observation: All 32 flaps survived with two cases in post operative phase, needing a flap elevation debridement of underlying bone and other skin grafting.Result: None of the case showed any vascular insufficiency, graft muscle loss or any functional loss. Use of muscle flap a viable option in pretibial defects.Journal of Nepalgunj Medical College Vol.12(1) 2014: 2-5

Angiography reveals novel features of the retinal vasculature in healthy and diabetic mice

The mouse retina is a commonly used animal model for the study of pathogenesis and treatment of blinding retinal vascular diseases such as diabetic retinopathy. In this study, we aimed to characterize normal and pathological variations in vascular anatomy in the mouse retina using fluorescein angiography visualized with scanning laser ophthalmoscopy and optical coherence tomography (SLO-OCT). We examined eyes from C57BL/6J wild type mice as well as the Ins2Akita and Akimba mouse models of diabetic retinopathy using the Heidelberg Retinal Angiography (HRA) and OCT system. Angiography was performed on three focal planes to examine distinct vascular layers. For comparison with angiographic data, ex vivo analyses, including Indian ink angiography, histology and 3D confocal scanning laser microscopy were performed in parallel. All layers of the mouse retinal vasculature could be readily visualized during fluorescein angiography by SLO-OCT. Blood vessel density was increased in the deep vascular plexus (DVP) compared with the superficial vascular plexus (SVP). Arteriolar and venular typologies were established and structural differences were observed between venular types. Unexpectedly, the hyaloid artery was found to persist in 15% of C57BL/6 mice, forming anastomoses with peripheral retinal capillaries. Fluorescein leakage was easily detected in Akimba retinae by angiography, but was not observed in Ins2Akita mice. Blood vessel density was increased in the DVP of 6 month old Ins2Akita mice, while the SVP displayed reduced branching in precapillary arterioles. In summary, we present the first comprehensive characterization of the mouse retinal vasculature by SLO-OCT fluorescein angiography. Using this clinical imaging technique, we report previously unrecognized variations in C57BL/6J vascular anatomy and novel features of vascular retinopathy in the Ins2Akita mouse model of diabetes.