Anatomical variants of renal veins: A meta-analysis of prevalence

Early-Branched Short Renal Arteries Are False Multiple Renal Arteries

Background/Objectives: During retroperitoneal surgery, awareness of the anatomic variants of renal arteries (RAs) is essential. We aimed to determine the prevalence of early-branched (short) Ras, the bilateral morphologies of RAs in such cases, and to check for significant correlations regarding gender or side. Short RAs may be regarded as false multiple RAs and should be distinguished from true RAs. Methods: For the study, 185 archived angioCT files were randomly selected and evaluated for <1.5 cm RAs (106 male and 79 female cases). Simple regression and multiple regression tests, alongside ANOVA, were used for the statistical analysis. Results: Short RAs were found in 15/185 cases, 12 males and 3 females (8.1%), with short RAs found on the right side (2.7%), left side (4.86), and bilaterally (one case, 0.54%). The mean length was 9.46 mm. Short RAs were bifurcated in most cases and trifurcated in one case. In four other cases, peculiar RA anatomical patterns were found. They included a right RA origin of the right inferior phrenic artery, variable polar RAs, malrotated and ptotic kidneys, anteriorly dehiscent renal sinuses, and multiple RAs, including five right RAs, with the three inferior ones having precaval courses. Short RAs were not significantly related to gender (p > 0.05). There was a significant correlation between gender and right short RAs (p < 0.05). Conclusions: During renal transplant surgery, distinguishing between true and false multiple RAs is essential. While true multiple RAs may cause surgical discomfort, short RAs may be used as single RAs, but they should be carefully documented before donor nephrectomies.

The prevalence of the fenestrated left renal vein

PURPOSE

The left renal vein (LRV) is typically a single preaortic vein. The discovery of fenestrated LRVs (FLRVs), a rare occurrence previously reported only twice, has piqued our interest. We aimed to determine the prevalence of such variants using an angioCT batch.

METHODS

We meticulously studied archived angioCT files of 95 men and 55 women. The morphology of the LRVs was carefully checked on planar sections and by three-dimensional volume renderings, ensuring the accuracy of our findings.

RESULTS

In 3.34% of cases, four males and one female were found FLRVs. Their posterior projections on the aorta were variable. The FLRVs were either partly preaortic, immediately to the left side of the aorta, or at a distance to the left side of the aorta. There were three true FLRVs, with a single vein attached at the lateral end and two pseudo-fenestrations, with two veins attached laterally. The left suprarenal and gonadal veins drained, respectively, in the superior and inferior arms of the fenestrations. In 2/5 cases, the second left lumbar vein drained into the inferior arms of the fenestrations. In one case, the FLRV was traversed by the inferior segmental branch of the renal artery.

CONCLUSION

Our findings have significant implications for surgical procedures targeting the left renal pedicle. The FLRV, with its morphological and topographical variability, should be considered among the anatomical variations of the LRV that may impede or endanger such procedures. However, it can be accurately discriminated on angioCT scans, providing a potential solution to this challenge.

A rare combined variation of left renal vasculature in a human cadaver: embryological basis and clinical significance

Classically, a single renal artery supplies, and a single renal vein drains each kidney. The morphology and variations in the renal vascular structures are of great importance when performing any type of renal surgery. The present case describes a rare combination of renal vasculature variation in a formalin-fixed, Chinese male cadaver. In this case, the left kidney is drained by a main renal vein (MRV) and an inferior renal vein (IRV), the latter might be the remnant of the left dorsal renal vein during the embryonic period. Two sets of renal arteries are present in this case, possibly due to persistent mesonephric arteries during embryonic development. Describing such anatomical variations is not only of academic interest but also important to help radiologists with the correct interpretation of image examinations and for surgeons to be prepared in advance.

Concomitant circumaortic and retro-aortic left renal veins associated with fenestrated renal artery

Variations of the left renal vein can be in the form of circumaortic vein or renal collar, retro-aortic vein, additional renal vein, or multiple primary tributaries. We report a unique complex venous pattern of concomitant circumaortic and retro-aortic left renal veins associated with a fenestrated left renal artery. Two renal veins, anterior and posterior to the renal artery, originated from the renal hilum. The anterior vein was further divided into two branches. One branch passed through the fenestrated renal artery to continue as the anterior limb of the circumaortic vein. It received the suprarenal and gonadal veins and drained into the inferior vena cava. The other branch coursed posterior to the fenestrated renal artery and joined the posterior renal vein. The posterior renal vein was divided into two branches: one forming the posterior limb of the circumaortic vein, and the other continued obliquely downwards as the retro-aortic vein. Variations in the left renal vein have been implicated in several clinical conditions, such as varicocele and pelvic varices. It also plays a crucial role in renal transplantation, as the left kidney is often used as the donor organ. Even though many reports have been published on circumaortic and retro-aortic veins, the complex venous pattern associated with a fenestrated renal artery has not been reported previously.

Could Renal Vascular Variations Be Associated with Resistant Hypertension? A Single-Center Study

Background: Anatomical variations in renal vessels are common in humans. However, the clinical significance of these congenital vascular abnormalities remains incompletely understood. This study aimed to assess the prevalence and characteristics of renal vascular variants in patients with arterial hypertension (HTN) and their association with the development of resistant HTN. Methods: We screened 3762 consecutive hypertensive patients hospitalized in our clinic and identified 128 (3.4%) with resistant HTN. These patients were matched with 128 hospitalized patients with controlled HTN. All participants underwent contrast-enhanced computed tomography imaging of the kidneys, including renovasography. Results: Anatomical renal vascular variations were identified in 64 (25%) of the 256 participants: 49 (38.3%) of the 128 patients with resistant HTN and 15 (11.7%) of the 128 patients with controlled HTN (p < 0.001). Among patients with renal vascular abnormalities, 76.6% had resistant HTN, while 23.4% had controlled HTN (p < 0.001). A regression analysis demonstrated a strong association between the presence of renal vascular variants and the development of resistant HTN, with an odds ratio of 4.67. Conclusions: Anatomical renal vascular variations were found to be common among hypertensive patients in this study and were strongly associated with the development of treatment-resistant HTN.

The Incidence and Variants of the Reno-Hemiazygos Connection

Background/Objectives: Although common anomalies of the left renal vein (LRV) are pretty well documented in the literature, the drainage of the left renal blood via the hemiazygos vein lacks comprehensive support. We, therefore, aimed to study the incidence of the reno-hemiazygos connection (RHC). Methods: A total of 150 computed tomography scans (85 men and 65 women) were documented for the origin of an RHC from the LRV. Results: RHCs were found in 14/150 cases (9.34%). They were more prevalent in women (71.43%). In 11/14 cases, type 1 RHCs ascended directly along the postero-lateral left side of the aorta (direct hemiazygos flow). In 3/14 cases, type 2 RHCs (indirect hemiazygos flow) had a lumbar segment corresponding to the second lumbar vein and a pretransversary segment corresponding to an ascending lumbar vein. In 9/14 cases (64.29%), the RHC was connected to a typical LRV. In 1/14 cases (7.14%), the RHC was connected to the junction between the LRV and a left retropelvic tributary. In another case (7.14%), the RHC was connected to a retroaortic LRV and, in three cases (21.43%), to a circumaortic LRV. Triple left renal arteries were found in type 1 and, respectively, type 2 cases. The vertebral level of the inferior end of the RHC was variable, from the L1/L2 disc level to the L3 level. Conclusions: When present, the RHC serves to connect the superior and inferior caval systems. This may be physiologically of use or not, but surgically, it is a major anatomical risk factor for bleeding if its presence is not checked preoperatively.

Radiologic evaluation of the kidney transplant donor and recipient

The kidney is the most common solid organ transplant globally and rates continue to climb, driven by the increasing prevalence of end stage renal disease (ESRD). Compounded by advancements in surgical techniques and immunosuppression leading to longer graft survival, radiologists evermore commonly evaluate kidney transplant patients and candidates, underscoring their role along the transplant process. Multiphase computed tomography (CT) with multiplanar and 3D reformatting is the primary method for evaluating renal donor candidates, detailing renal size, vascular/collecting system anatomy, and identifying significant pathologies such as renal vascular diseases and nephrolithiasis. Ultrasound is the preferred initial postoperative imaging modality for graft evaluation due to its low cost, accessibility, noninvasiveness, and lack of radiation. CT and magnetic resonance imaging (MRI) may be useful adjunctive imaging techniques in diagnosing transplant pathology when ultrasound alone is not diagnostic. Kidney transplant complications are categorized by an approximate timeline framework, aiding in differential diagnosis based on onset, duration, and severity and include perinephric fluid collections, graft compression, iatrogenic injuries, vascular compromise, graft rejection, and neoplastic processes. This review discusses imaging strategies and important findings along the transplant timeline, from donor assessment to long-term recipient complications.

Retroaortic Left Renal Vein: A Case Report

A retroaortic left renal vein (RLRV) is the term applied to a left renal vein that passes posterior to the abdominal aorta. Typically, the left renal vein traverses horizontally, passing anterior to the abdominal aorta and inferior to the superior mesenteric artery (SMA), before draining into the medial side of the inferior vena cava (IVC). Here, we present a case highlighting type I of the four distinct retroaortic variations observed in the left renal vein. Its prevalence is often underrepresented in medical education despite a clinically significant prevalence in the general population. It is crucial to possess preoperative awareness of this variant to mitigate potential complications linked to vascular damage to the RLRV. These complications encompass severe hemorrhage, renal injury, the necessity for nephrectomy, and, in extreme cases, fatal outcomes during retroperitoneal surgery or interventional procedures. This case report aims to emphasize the significance of incorporating RLRV anomalies into medical education to improve clinical awareness and diagnostic accuracy. The RLRV discussed in this case report was discovered posthumously in an anatomical donor.

Prevalence of rare anatomic variants - publication bias due to selective reporting in meta-analyses studies

Meta-analyses of prevalence studies reporting rare anatomic variants are prone to selective reporting of non-null, confirmatory results, thus resulting in publication bias.

The accessory renal arteries: A systematic review with meta-analysis

The accessory renal arteries (ARAs) are a well-described variant of the renal vasculature with clinical implications for radiologists, surgeons, and clinicians. The aim of the present systematic review with meta-analysis was to estimate the pooled prevalence of ARAs, including their variant number, origin, and termination, and to highlight symmetrical and asymmetrical morphological patterns. The systematic review used four online databases in accordance with PRISMA 2020 and Evidence-based Anatomy Workgroup guidelines. R programming software was used for the statistical meta-analysis. A total of 111 studies were considered eligible for our initial aim. The typical renal artery (RA) anatomy (a single bilateral vessel) was identified in 78.92%; the overall ARA prevalence was estimated at a pooled prevalence of 21.10%. The estimated pooled prevalence of one, two, three, and four ARAs were 18.67%, 1.80%, 0.01%, and <0.01%. The ARAs have been the subject of extensive research owing to their clinical importance, including in kidney transplantation surgery and resistant hypertension therapy. Knowledge of the typical and variant anatomy of RAs is essential for anatomists, radiologists, surgeons, and clinicians in order to avoid misunderstanding, complications, and iatrogenic injury.

Unveiling the uncommon: Exploring a rare variant in right ovarian vein drainage: A case report

INTRODUCTION AND IMPORTANCE

The right ovarian vein typically drains into the inferior vena cava, while the left ovarian vein terminates in the left renal vein. Variations in the drainage pattern of the ovarian veins are infrequent, with reported incidences ranging from 0.03 % to 9.9 % across various studies. However, rare anatomical variations can significantly complicate surgical procedures, particularly lymphadenectomy for ovarian cancer.

CASE PRESENTATION

We present a case of a patient in her 40s referred to Salah Azaiez Institute for ovarian cancer management. We performed ovarian staging. During the retroperitoneal lymphadenectomy, we identified an unusual anatomical variation in the drainage of the right ovarian vein.

CLINICAL DISCUSSION

Anatomical variations of the ovarian and renal veins, although rare, have significant clinical implications. A cadaveric study revealed that only 3 out of 94 dissected ovarian veins exhibited variations, with one draining into the inferior vena cava (0.01 %). Such variations can lead to vascular and postoperative complications, emphasizing the need for vascular surgeons, urologists, and oncologists to understand these anomalies thoroughly. Preoperative imaging using computed tomography angiography is crucial for identifying these variations before surgical interventions, thus enhancing surgical planning and clinical outcomes.

CONCLUSION

This case underscores the importance for surgeons to be aware of anatomical variations during retroperitoneal surgeries to prevent complications and ensure optimal surgical outcomes.

Polysplenia with situs inversus totalis, azygos continuation of the inferior vena cava, and duplication of the superior vena cava in a healthy adult: A case report

Polysplenia syndrome is an embryological disorder whereby the usual left-right asymmetry of thoracic and abdominal viscera fails to develop. It is a rare entity, estimated to occur at a frequency of 1 in 40,000, and is often associated with cardiac and biliary abnormalities. More than 75% of patients die before the age of 5 years, and even in the absence of cardiac anomalies, only 5%-10% of patients are expected to survive into adulthood without complications. Although polysplenia syndrome encompasses a wide range of anatomic abnormalities, there is no single pathognomonic feature. Hence, the prognosis of patients with polysplenia depends on their anatomy, thus necessitating radiology in their management. Here we present a case of a 56-year-old man with polysplenia syndrome and situs inversus totalis. This presentation is atypical because polysplenia is usually considered a form of situs ambiguus, and cases with situs inversus totalis are exceedingly rare. Also noted in our patient are variations in the great vessels, including aortic arch branches and the venae cavae which are features not typically associated with either polysplenia syndrome or situs inversus totalis. The patient is healthy and asymptomatic at baseline, with his diagnosis being made incidentally. Our case report is the first to describe this unique combination of cardiothoracic and cardiovascular anatomy. It also emphasizes the importance of radiologists in caring for patients with laterality defects. As these disorders are uncommon, more data on their anatomic variations may help provide better medical care to this patient population.

Anterior Column Realignment Using an Anterior-To-Psoas Approach: A Radiographic-Anatomic Feasibility Study at L1-L5

STUDY DESIGN

Cross-sectional radioanatomic study.

OBJECTIVE

To determine the feasibility of performing an anterior column realignment (ACR) using an anterior-to-psoas (ATP) approach at L1-L5.

METHODS

Axial magnetic resonance images (MRI) of the L1-L5 disc levels obtained at a single institution were obtained and analyzed. The feasibility of performing an ACR was assessed using a combination of the size of the left oblique corridor (OC), the psoas morphology using the modified Moro classification, and the anterior disc edge to great vessel distance.

RESULTS

Three hundred MRI studies obtained from 300 patients were included. All patients had a measurable left OC at the L1-L4 levels. Twenty patients (6.7%) had no measurable OC at the L4-L5 level. According to the modified Moro's classification, a high-rising psoas was seen in 4 patients (1.3%) at the L3-L4 level and 57 patients (19.0%) at the L4-L5 level. An ALL release was considered high risk due to no measurable space between the anterior disc edge and the great vessels in 54 patients (18.0%) at the L1-L2 level, 39 patients (13.0%) at the L2-L3 level, 119 patients (39.7%) at the L3-L4 level, and 226 patients (75.3%) at the L4-L5 level.

CONCLUSION

ACR using an ATP approach is the most radioanatomically feasible at L2-L3. The L4-L5 level has the highest risk with regards to both the ATP approach and the ALL release for an ACR due to high rates of unmeasurable left OC and space between the anterior disc edge and the great vessels.

Doppler Ultrasound of the Renal Vasculature

Ultrasound is the first-line imaging modality used in patients with suspected renovascular disease. Common indications include renovascular hypertension and unexplained renal dysfunction. We review the ultrasound imaging findings of various pathologies involving the renal vessels, including the renal arteries (atherosclerotic stenosis, fibromuscular dysplasia, dissection, arteriovenous fistula, and aneurysm) and veins (tumor and bland thrombus as well as vascular compression syndromes). The current role of renal artery stent placement for atherosclerotic stenosis is also discussed.

Anatomical Variants of the Renal Veins and Their Relationship with Morphofunctional Alterations of the Kidney: A Systematic Review and Meta-Analysis of Prevalence

Background: Variations in renal veins are quite common, and most people do not experience issues due to them. However, these variations are important for healthcare professionals, especially in surgical procedures and imaging studies, as precise knowledge of vascular anatomy is essential to avoid complications during medical interventions. The purpose of this study was to expose the frequency of anatomical variations in the renal vein (RV) and detail their relationship with the retroperitoneal and renal regions. Methods: A systematic search was conducted in the Medline, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS databases from their inception until January 2024. Two authors independently carried out the search, study selection, and data extraction and assessed methodological quality using a quality assurance tool for anatomical studies (AQUA). Ultimately, consolidated prevalence was estimated using a random effects model. Results: In total, 91 studies meeting the eligibility criteria were identified. This study included 91 investigations with a total of 46,664 subjects; the meta-analysis encompassed 64 studies. The overall prevalence of multiple renal veins was 5%, with a confidence interval (CI) of 4% to 5%. The prevalence of the renal vein trajectory was 5%, with a CI of 4% to 5%. The prevalence of renal vein branching was 3%, with a CI of 0% to 6%. Lastly, the prevalence of unusual renal vein origin was 2%, with a CI of 1% to 4%. Conclusions: The analysis of these variants is crucial for both surgical clinical management and the treatment of patients with renal transplant and hemodialysis.

Protean Drainage Patterns of the Left Renal Vein: A Cadaveric and Retrospective Clinical Study on the Surgical Implications and Technical Feasibility

BACKGROUND

The diverse drainage patterns of the left renal vein (LRV), often with asymptomatic congenital anomalies, present considerable challenges in renal and retroperitoneal surgical contexts. The potential for significant bleeding and subsequent renal compromise upon vascular injury highlights the need for increased surgical awareness.

OBJECTIVE

This study investigates the LRV's variable anatomical drainage patterns and morphometry. It also evaluates the embryological factors contributing to these variations and discusses their surgical implications and technical considerations.

METHODS

Anatomical dissections were conducted on 21 adult human cadavers within the Department of Anatomy. Concurrently, a retrospective analysis was conducted on 15 patients who underwent various retroperitoneal surgical interventions in the Urology Department. Demographic variables and intraoperative findings were recorded and analyzed.

RESULTS

Dissection analysis predominantly identified preaortic LRVs in 18 cadavers. Notable anatomical variations included a circumaortic left renal vein (CLRV), a delayed preaortic confluence of extrahilar duo LRVs, and an extrahilar tetramerous confluence with a retroiliac topography. The majority of LRVs usually end in the inferior vena cava. However, an extrahilar tetramerous variant had an unusual drainage pathway. Out of 15 cases, three (20%) had a retroaortic left renal vein (RLRV). One patient with a nonfunctioning kidney had type 1 RLRV, and another patient with pelvic ureteric junction obstruction had type 4 retroiliac left renal vein (RILRV). In both of these patients, symptoms were relieved after surgery. In a young patient with left varicocele and microscopic hematuria who had type 2 RLRV, symptoms resolved spontaneously after a few months.

CONCLUSION

A thorough understanding of the variable anatomical drainage patterns of the LRV is crucial for surgeons. Accurate preoperative identification can provide valuable insights, potentially leading to improved surgical outcomes in renal procedures.

Pre-operative colour Doppler ultrasound for the prevention of bleeding complications after renal biopsy: A rare case of left renal lower pole vein

Albeit rare, renal vein abnormalities on autopsy and in cases of abdominal surgery complications have been reported and should be kept in mind when performing invasive procedures, such as renal biopsy. We detected a rare renal vein abnormality on colour Doppler ultrasound before renal biopsy, thereby, avoiding a haemorrhagic complication. A 10-year-old boy presented to our department for the first time because of incidental findings of haematuria and proteinuria. We suspected chronic glomerulonephritis and scheduled an ultrasound-guided percutaneous renal biopsy. A simple screening ultrasound at the initial visit revealed no renal or vascular abnormalities. The day before the renal biopsy, we confirmed the biopsy site by performing a colour Doppler ultrasound, which showed abnormal blood flow from the lower pole of the left kidney, which was the planned puncture site; therefore, we changed the biopsy site to the right and completed the examination. Subsequent computed tomography angiography depicted two renal veins; one was the usual left renal vein draining from the kidney hilum, and the second was an accessory vein draining from the inferior pole of the left kidney and entering the inferior vena cava through the dorsal side of the aorta. Although rare, abnormalities in the renal vessels on the inferior pole of the kidney, which is the usual site of renal biopsy, are essential to rule out preoperatively by colour Doppler ultrasound, because these can cause significant bleeding during renal biopsy if not recognized.

The anterior communicating artery variants: a meta-analysis with a proposed classification system

Morphological and morphometric variants of the anterior communicating artery (AComA) have been described by multiple studies; however, a complete classification system of all possible morphological variants with their prevalence is lacking. The current systematic review with meta-analysis combines data from different databases, concerning the AComA morphological and morphometric variants (length and diameter). Emphasis was given to the related clinical implications to highlight the clinical value of their knowledge. The typical AComA morphology occurs with a pooled prevalence (PP) of 67.3%, while the PP of atypical AComA is 32.7%. The identified AComA morphological variants (artery's hypoplasia, absence, duplication, triplication, differed shape, fenestration, and the persistence of a median artery of the corpus callosum- MACC) were classified in order of frequency. The commonest presented variants were the AComA hypoplasia (8%) and the anterior cerebral artery (ACA) fusion (5.9%), and the rarest ones were the MACC persistence (2.3%), and the AComA triplication (0.7%). The knowledge of those variants is essential, especially for neurosurgeons operating in the area. Given the high prevalence of AComA aneurysms, an adequate and complete classification of those variants is of utmost importance.

Renal Artery Triplication: An Unusual Morphological Variant

Renal vasculature depicts great morphological variability and clinical significance due to the great number of procedures performed on kidneys. The current imaging report presents a right-sided renal artery (RA) triplication and origin from the abdominal aorta (AA), which was incidentally identified during computed tomography angiography (CTA). The typical RA corresponded to the main hilar artery (MHA), the second RA corresponded to the superior polar artery (SPA), and the third RA corresponded to the inferior polar artery (IPA). RA triplication occurs in 0.9%-4.5% and depicts wide morphological variability. The current report corresponds to one superior polar, one inferior polar, and a main hilar renal artery, which represents a rare morphological type of RA triplication. Kidney transplantation surgery, endoscopic surgery, and renal angiography require adequate knowledge of RAs and their variants to avoid pitfalls and iatrogenic lesions from clinicians.

Two rare cases of circumaortic left renal vein with double retroaortic limbs and its procedural implications

Circumaortic left renal vein with additional retroaortic limb is a rare anatomic variant. We encountered two cases in our practice with additional retroaortic limb draining into hemiazygos and IVC respectively. We focus on discussing the clinical relevance and surgical implications of such variants.

Laparo-Endoscopic Single-Site Left Donor Nephrectomy In Patients With Uncommon Renal Vascular Anatomy: Does the Technique Make a Difference?

BACKGROUND

To compare donor and recipient outcomes in patients with renal artery and ante-aortic renal vein vs unusual renal vascular anatomy undergoing laparoendoscopic single-site donor nephrectomy (LESSDN).

METHODS

A retrospective chart review of the comparative study of donor and recipient outcomes of LESSDN in donors with venous abnormality (n = 28, group A), arterial abnormality (n = 74, group B), and standard donors (n = 248, group C).

RESULTS

From September 2016 to August 2022, 350 left LESSDN were performed. The most common anomalies in group A were the retro-aortic and 2 renal veins in 12 patients each. In group B, 72 and 2 patients had 2 and 3 renal arteries, respectively. Operative and warm ischemia times were significantly longer in donors with vascular anomalies. Moreover, patient creatinine on discharge was significantly higher in arterial anomalies; it was 1.61 ± 0.22 compared with 1.26 ± 0.43 and 1.25 ± 0.32 mg/dL for patients with no anomalies and venous anomalies, respectively (P < .001). However, serum creatinine levels recovered after 1 month and were comparable between the study groups. Recipients, operative time, and vascular anastomosis time were significantly longer in recipients with vascular anomaly. Slow graft function was higher in group B (6.9%) than in the other groups. One-year graft survival rates were 96.4%, 94.6%, and 97.1% (P = .496).

CONCLUSION

With increased experience, LESSDN in multiple renal arteries and uncommon venous anatomy cases is feasible and safe. Moreover, it does not influence donor or recipient outcomes.

Anatomical variants of the retroaortic left renal vein

BACKGROUND

Anatomical variants of the left renal vein (LRV), such as the retroaortic (RLRV) and circumaortic (CLRV) course, are of surgical importance. Different morphological and topographical possibilities of the RLRV could occur. It was aimed at documenting the anatomical variables of the RLRV.

METHOD

A retrospective study on 375 computed tomography angiograms was performed. Five different anatomical types of LRV were documented: preaortic types 1 and 2 and retroaortic types 3-5.

RESULTS

In 344/375 cases, preaortic LRVs were found. In 31/375 cases, different types of RLRV were found: type 3a - single RLRV, 41.94%; type 3b - single RLRV with bifid caval end, 9.68%; type 3c - single RLRV with trifid caval end, 3.23%; type 4a - CLRV with extrahilar origin, 29.03%; type 4b - CLRV with renal sinus origin, 12.9%; type 5 - triple LRV (one preaortic LRV and two RLRVs), 3.23%. Reference vertebral levels were recorded for the prevertebral segment of the RLVR. The vertebral level of type 3a varied from the L1/L2 disc to the upper third of the L4 vertebra. Type 3b was found in 3/31 RLRV cases; in one of these, the hemiazygos vein was inserted by two roots into the LRV and its upper caval end trunk. There was a significant statistical association between type 3b and the vertebral level, all cases being centered on the middle third of the L4 vertebra.

CONCLUSIONS

New morphological possibilities of the LRV were distinguished, and a new anatomical classification system of the RLRV results. The RLRV variant should be documented case-by-case as it has its anatomical variables.

A Practical Guide for Left Adrenal Vein Sampling in Patients with Left Renal Vein Variants

BACKGROUND

The presence of left renal vein (LRV) variants can increase the complexity of adrenal vein sampling (AVS), an already technically demanding procedure. While AVS literature often focuses on the right adrenal vein, an understanding of common LRV variants, their relationship with the left adrenal vein, and principles for successful catheterization can facilitate AVS. This guide provides practical, technical tips for AVS for duplicated (Du), circumaortic (Ca), and retroaortic (Ra) LRVs.

METHODS

AVS cases were identified at a single institution (June 2009-March 2023) based on adrenophrenic trunk drainage relative to variant LRVs. Available cross-sectional imaging was reviewed to evaluate LRV anatomy pre-procedure. Twenty-seven cases (1 DuLRV, 13 CaLRVs, and 13 RaLRVs) were identified. Diagnostic AVS was confirmed by a threshold selectivity index. Literature on LRV anatomic variants was also reviewed.

RESULTS

Based on the authors' experience and literature review, the following principles can guide AVS in the setting of LRV variants. In the presence of DuLRV or CaLRV, the left adrenal vein invariably drains into a normally positioned, pre-aortic LRV limb, so AVS can proceed as expected with a Simmons as the catheter of choice. In contrast, a LAV draining into a RaLRV may require a hockey stick-like catheter, or in rare cases a microcatheter, for selecting and sampling, due to the longer RaLRV course, which usually drains into the IVC more inferiorly and can be stenotic where the aorta crosses.

CONCLUSION

Knowing the presence and understanding the anatomy of LRV variants can facilitate an efficient AVS.

Surgical Management of Renal Cell Carcinoma with Inferior Vena Cava Tumor Thrombus

Most kidney cancers are primary renal cell carcinomas (RCC) of clear cell histology. RCC is unique in its ability to invade into contiguous veins - a phenomenon terms venous tumor thrombus. Surgical resection is indicated for most patients with RCC and an inferior vena cava (IVC) thrombus in the absence of metastatic disease. Resection also has an important role in selected patients with metastatic disease. In this review, we discuss the comprehensive management of the patient with RCC with IVC tumor thrombus, emphasizing a multidisciplinary approach to the surgical techniques and perioperative management.

Multiple renal veins clogging the hilum of the right kidney

Knowledge of variations of renal vessels is of utmost importance in retroperitoneal surgeries and kidney transplant surgeries. We report concurrent variations of the right renal vessels, observed in an adult male cadaver during dissection classes. The right kidney was supplied by three renal arteries, out of which two entered the kidney through the hilum and the other one entered through the lower pole of the kidney. There were five renal veins, emerging independently from the hilum and opening separately through five openings into the inferior vena cava. Among the veins, only one emerged anterior to the renal pelvis and the other four emerged behind it. Four of them terminated into the posterolateral aspect of the inferior vena cava, whereas one terminated into its anterior aspect. Fourth vein from above, received the right testicular vein. The renal hilum was clogged with the presence of seven vessels and renal pelvis.

Superior Mesenteric Artery Injury during Robotic Radical Nephrectomy: Scenarios and Management Strategies

Injury to the superior mesenteric artery (SMA) is a rare, underreported, and potentially devastating complication. This study aims to propose a systematic workup to describe how to prevent and manage SMA injury in a standardized stepwise manner. Three different instances of intraoperative injury to the SMA are described in an accompanying video. All three occurred when the SMA was misidentified as the left renal artery during left robotic radical nephrectomy. In the first case, the SMA was mistakenly identified as the renal artery, but after further dissection, the real renal artery was identified and SMA injury was prevented. In the second case, the SMA was clipped and the real left renal artery was subsequently identified, requiring clip removal. In the third case, the SMA was clipped and completely transected, requiring prompt repair by vascular surgery with a successful outcome. This study aims to propose a systematic workup to describe how to prevent and manage SMA injury in a standardized stepwise manner. The proper anatomic recognition of the SMA may prevent its injury. Intraoperative SMA injury should be promptly identified and repaired to avoid its devastating consequences.

Left renal vein graft and in situ hepatic perfusion in hepatectomy for complete tumor invasion of hepatic veins: hemodynamic optimization and surgical technique

PURPOSE

Assessing hepatic vein reconstruction using a left renal vein graft and in situ hypothermic liver perfusion in an extended liver resection.

METHODS

Patients included in this study were those with liver tumors undergoing curative surgery with resection and reconstruction of hepatic veins. Hepatic vein was reconstructed using a left renal vein graft. We describe the technical aspects of liver resection and vascular reconstruction, the key aspects of hemodynamic management, and the use of in situ hypothermic liver preservations during liver transection (prior to and during vascular clamping).

RESULTS

The right hepatic vein was reconstructed with a median left renal venal graft length of 4.5 cm (IQR, 3.1-5.2). Creatinine levels remained within normal limits in the immediate postoperative phase and during follow-up. Median blood loss was 500 ml (IQR, 300-1500) and in situ perfusion with cold ischemia was 67 min (IQR, 60.5-77.5). The grafts remained patent during the follow-up with no signs of thrombosis. No major postoperative complications were observed.

CONCLUSION

Left renal vein graft for the reconstruction of a hepatic vein and in situ hypothermic liver perfusion are feasible during extended liver resection.

MR Angiography Series: Abdominal and Pelvic MR Angiography

This review guides readers through the selection and setup of standardized MR angiography (MRA) protocols for the abdomen and pelvis for common clinical applications. Topics covered include renovascular MRA in potential kidney donors and in patients with hypertension; hepatic and mesenteric MRA in potential liver donors, patients with portal hypertension, and patients with chronic mesenteric ischemia; pelvic MRA for pretreatment planning before uterine fibroid embolization and in patients with pelvic congestion syndrome; and abdominal wall MRA for planning of breast reconstructive surgery. This module is the fifth in a series created on behalf of the Society for Magnetic Resonance Angiography (SMRA), a group of researchers and clinicians who are passionate about the benefits of MRA but understand its challenges. The full digital presentation is available online. ©RSNA, 2022.

Paraaortic Lymphadenectomy in Gynecologic Oncology—Significance of Vessels Variations

Lymphadenectomy has been an essential part of the surgical treatment in surgical oncology, as the lymphatic channels and nodes are the main dissemination pathway for most of the gynecological cancers. Pelvic and paraaortic lymphadenectomy are frequent surgical procedures in gynecologic oncology. Paraaortic lymph node dissection facilitates staging, prognosis, surgical and postoperative management of patients. It is one of the most challenging retroperitoneal surgeries. A comprehensive knowledge of the paraaortic region is mandatory. Intraoperative bleeding is the most common complication during lymphadenectomy due to direct vascular injury, poor tissue handling, exuberant retraction and possible anatomical variations of the vessels in the paraaortic region. Approximately, one-third of women will have at least one anatomic variation in the paraaortic region. It must be stressed that anomalous vessels may be encountered in every woman who will undergo surgery. Consequently, detailed knowledge of anatomical vessels variations is required in order to prevent iatrogenic vessel injury. The importance of these variations is well described in urology, vascular and general surgery. Conversely, in oncogynecological surgery, there are few articles, which described some of the vessels variations in the paraaortic region. The present article aims to propose a surgical classification and to describe the majority of vessels variation, which could be encountered during paraaortic lymphadenectomy in gynecologic oncology. Moreover, surgical considerations in order to prevent anomalous vessels injury are well described.

Safety and Intraoperative Results in Live Kidney Donors with Vascular Multiplicity After Hand-Assisted Laparoscopy Living Donor Nephrectomy

Background and Purpose

Vascular multiplicity is the most frequent anatomic variation in kidney donors. Despite concerns about risks, these allografts are increasingly used to overcome the shortage of kidney donors. The safety and clinical outcomes in living kidney donors were evaluated with vascular multiplicity after hand-assisted laparoscopic living donor nephrectomy (HALDN).

Patients and Methods

Data from all living kidney donors who underwent HALDN from 2008 to 2021 was retrospectively reviewed. Patients were divided into two groups as single (SRV) and multiple renal vessels (MRV), and a comparative analysis was done. The primary outcomes include operating room time (ORT), days of hospital stay, estimated blood loss, complications, conversion, and re-operations.

Results

MRV were present in 166 out of 612 donors (27.1%). Among those, 10 (1.6%) donors had simultaneous multiple arteries and veins. Additionally, the prevalence of artery and vein multiplicity was 21.8% (n = 134) and 3.5% (n = 22), respectively. Warm ischemia time was significantly different among the two groups but not clinically important. The number of conversions to open technique, the mean ORT, the median blood loss, and days of hospital stay were similar between the SRV and MRV groups, without significant differences. According to the modified Clavien-classification system, no differences were found in the complication rates between the two groups (p = 0.29). Complication rates were 3.3% and 3.6% for the SRV and MRV groups, respectively.

Conclusion

HALDN is a procedure with safe intraoperative results, even with vascular multiplicity. The presence of multiple renal arteries or veins has no negative impact on the outcome of the donor after living donor nephrectomy.

Angioplasty and angiorrhaphy efficiency in renal transplantation scenarios with multiple arteries and veins

OBJECTIVE

To evaluate post-transplant renal perfusion and vascular complications of renal transplantation in patients with the end-stage renal disease (ESRD) operated in the presence of multiple blood vessels at Viet Duc University Hospital.

METHODS

A non-controlled interventional study was performed prospectively and retrospectively between January 2012 and June 2018. The study sample includes 84 patients who underwent live donor renal transplantation in the presence of multiple arteries (RAs) and veins (RVs) at Viet Duc Hospital. The surgical procedure comprised of end-to-side anastomosis to the recipient's external iliac artery/vein, gun barrel anastomosis of two RAs/RVs, anastomosis of the small RA/RV to the main RA/RV, anastomosis of the polar artery to the inferior epigastric artery, small artery constriction, and their combinations.

RESULTS

On clamp removal, 94% of the transplanted kidneys were solid and evenly pink, 3.6% had bruises due to small artery constriction, 1.2% were poorly perfused due to vasoconstriction, and 1.2% had renal artery branches occluded by blood clots and required anastomosis re-opening. All kidneys began to produce urine on the operating table.

CONCLUSION

A high success rate of renal transplantation in the presence of multiple blood vessels requires that surgeons have sufficient experience and use a combination of angioplasty and angiorrhaphy techniques.

Left double polar renal arteries, left triplicate (preaortic, accessory and retroaortic) renal veins associated with extrinsic pelviureteric junction obstruction and posterior nutcracker phenomenon

The renal vasculature and its various congenital anomalies have been studied and documented widely in the literature. However, the concomitant occurrence of renovascular morphological anomalies with vascular compression phenomena in a single patient is a rarity. This is a case of a patient with double left renal arteries, preaortic, accessory and retroaortic left renal veins. There was also associated with vascular compression phenomena in the form of posterior nutcracker phenomenon and pelviureteric junction obstruction (PUJ) due to the double-crossing inferior left polar renal artery and retroaortic vein.

Die Anatomie des retroperitonealen und pelvinen Venensystems

Venenleiden sind nicht auf die Extremitäten beschränkt. Einerseits können Erkrankungen der Beinvenen wie Varikose und Phlebothrombose auch die Venen der Beckenorgane und des Retroperitoneums mit betreffen, andererseits sind pelvine und abdominelle Symptome mitunter auch phlebogen erklärbar. Als Pendant zur chronischen venösen Insuffizienz der Beinvenen hat sich der Begriff des chronischen pelvinen Stauungssyndroms etabliert, der die Komplexität der Störung weder anatomisch noch funktionell adäquat erfasst.

Die klinische Diagnostik und die Bildgebung, insbesondere die Duplexsonografie der retroperitonealen Venen, sind erheblich schwieriger als die der Beinvenen. Darüber hinaus sind die Gefäße sehr variantenreich. Die fundierte Kenntnis der Anatomie der pelvinen und retroperitonealen Gefäße ist unersetzlich, um die möglichen Befunde deuten zu können. Das Wissen um die wichtigsten embryologischen Entwicklungsschritte erleichtert das Verständnis pathophysiologischer Mechanismen.

Anastomosis of dual renal transplant veins

As there is usually considerable overlap in the renal venous drainage, it is often possible to ligate supernumerary transplant renal veins in order to simplify the implantation procedure. Nonetheless, decisions about whether to implant multiple veins can be difficult and are usually made subjectively. Here, we describe the use of intraoperative Doppler ultrasound as an adjunct to decision-making when there are two renal veins and a novel technique for the sequential anastomosis of dual veins. The kidney was reperfused after anastomosis of the main renal vein with the second vein clamped. On-table Doppler ultrasound demonstrated reversed flow in diastole indicating that the second renal vein also needed to be anastomosed. By clamping the external iliac vein inferior to the first venous anastomosis it was possible to complete the lower polar renal vein anastomosis to the external iliac vein without interrupting the perfusion of the kidney.