Embryological consideration of drainage of the left testicular vein into the ipsilateral renal vein: analysis of cases of a double inferior vena cava

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.

Bilateral duplicated inferior vena cava associated with aberrant internal iliac and gonadal veins: A case-based narrative review

BACKGROUND

The left side anterior retroperitoneal approach is preferred for the management of lumbosacral spine disorders as there is reduced risk for vascular injury. The presence of multiple and uncommon venous variations on either side of the spine, like the bilateral duplicated inferior vena cava (DIVC), may complicate surgery in this region. The current study describes two rare cases of bilateral duplicated inferior vena cava associated with internal iliac and gonadal veins.

METHODS

The cases were identified during routine human dissections of the posterior abdominal wall of 89 (45 males, 44 females) individuals. The course, relations and morphometry of each duplicated inferior vena cava were examined and recorded.

RESULTS

Two (2.2%) of the 89 (1 male, 1 female) dissected individuals showed the presence of bilateral duplicated infrarenal segments of the inferior vena cava. In both cases, the pre-aortic trunk (vein) was the largest and the left inferior vena cava was the smallest. Both cases of bilateral DIVC presented with anomalous interiliac communicating veins, internal iliac veins, and drainage sites of the left gonadal veins.

CONCLUSIONS

The duplicated inferior vena cava may present with associated venous anomalies like those related to the gonadal and internal iliac veins. Knowledge of the duplicated inferior vena cava and its associated venous anomalies may be essential for accurately identifying and diagnosing vascular dysfunction and improving radiological interpretation across multiple surgical specialities.

Anatomic Variation of Type III Right Testicular Venous Drainage: A Case Report

The testicular vein exhibits variations in number, course, and insertion. Such differences may enhance the risk of varicocele and complication in patients by impairing testicular drainage. The following is a case report of the abnormal drainage of the right testicular vein (RTV) draining into the right renal vein (RRV). The incidence, course, insertion, and termination angle of the testicular veins were measured with a 150 mm digital Vernier dial microcaliper, and photographs were taken by Canon EOS 70D using a 100mm macro lens. In one out of seven cadavers (14.28%), the right testicular vein (RTV) drained into the right renal vein (RRV) (Type III) rather than into the inferior vena cava (IVC) at a 90° angle 0.4 cm from the IVC. The double (medial and lateral) left testicular veins (LTV) drained into the left renal vein (LRV) at a 62° angle 5 cm from the IVC. The understanding of type III RTV drainage or course can provide crucial data for surgeons in order to prevent complications during right-sided varicocele surgery.

Curated findings and implications in duplex ultrasound interrogation of the scrotum or varicoceles

The purpose of this study was to curate clustered findings of duplex ultrasound in the evaluation of spermatic venous varicoceles, and deliver more responses to the present concerns. Archives of 979 men who had undergone scrotum and spermatic venous plexus duplex ultrasound were reviewed. In the duplex ultrasound interrogation, the sizes of the larger vessels of the spermatic venous plexus, peritesticular vessels, and testicular volume and relevant parameters were measured. Findings of the vessels were analyzed. One hundred and eight-one out of 979 patients had varicoceles. Color Doppler flow signal was rendered in veins of pampiniform plexus but not in peritesticular vessels in 501 out of 979 patients; 101 out of 501 patients had veins of pampiniform plexus ≤ 3 mm, no color Doppler flow signal could be rendered in the veins in the 101 patients at supine and standing positions without Valsalva maneuver, color Doppler flow signal could be rendered in the veins in 82 out of 101 patients at supine and standing positions with Valsalva maneuver; no color Doppler flow signal could be rendered in the veins from 19 out of 101 patients with and without Valsalva maneuver at supine and standing positions. 37 out of 979 patients with 61 ipsilateral testicular volume ≤ 5 mL had no vessel diameter > 2 mm. The incidences of varicoceles corresponding to different ranges of testicular volume of 1-5 mL, 5.1-10 mL, 10.1-15 mL, 15.1-20 mL, 20.1-25 mL, and 25.1-30 mL were 0.0%, 6.9%, 8.3%, 6.63%, 20.94%, and 59.1%, respectively. The comparisons of incidences of varicocele between distribution percentages of different ranges of testicular volume of 1-5 mL and others (of 5.1 mL and more) were all significant (all P < 0.05). The correlation coefficient between the different ranges of testicular volume and the incidence of varicoceles was 0.829. Increased testicular volume may be also a factor for the development of varicoceles. Dilated peritesticular vessels may be collateral veins of spermatic veins, anterior and posterior scrotal veins, or proximal vas deferens.

Increased supply from blood vessels promotes the activation of dormant primordial follicles in mouse ovaries

The controlled activation of dormant primordial follicles is important for the maintenance of periodic ovulation. Previous reports have clearly identified the signaling pathway in granulosa cells and oocytes that controls the activation of primordial follicles; however, the exact cue for the in vivo activation of dormant primordial follicles is yet to be elucidated. In this study, we found that almost all activated primordial follicles made contact with blood vessels. Based on this result, we speculated that the contact between primordial follicles and blood vessels may provide a cue for the activation of dormant primordial follicles. To confirm this hypothesis, we attempted to activate dormant primordial follicles within the ovaries by inducing angiogenesis through the use of biodegradable gels containing recombinant vascular endothelial growth factor and in cultured ovarian tissues by increasing the serum concentration within the culture medium. The activation of dormant primordial follicles was promoted in both experiments, and our results indicated that an increase in the supply of the serum component, from new blood vessels formed via angiogenesis, to the dormant primordial follicles is the cue for their in vivo activation. In the ovaries, angiogenesis often occurs during every estrous cycle, and it is therefore likely that angiogenesis is the crucial event that influences the activation of primordial follicles.

Variations of the testicular artery and vein: A meta-analysis with proposed classification

Variations of testicular vessels are more common than supposed. The testicular artery varies because of abnormal regression of the lateral mesonephric arteries in the fetus, whereas variations in the testicular vein are due to abnormalities in the involution of the intersubcardinal anastomosis. Such variations are usually found incidentally during surgical procedures around the renal pedicle and they often lead to complications. Several authors have attempted to classify them. However, these attempts have not been comprehensive. Therefore, the aim of this study is to provide a simple yet comprehensive classification of variations of the testicular vessels. The PubMed database was searched using keywords pertaining to the testicular vessels. The results were subjected to the Anatomical Quality Assessment (AQUA) tool analysis and were screened for appropriateness for inclusion in this study. The screening procedure yielded 31 original articles, 83 case reports, and 1 review article. Both testicular arterial and venous variations were more common on the left side (20.73% and 24.61%) than the right (12.69% and 18.4%, respectively). We classified the testicular arteries on the basis of their number (N), site of origin (O), and course (C). Similarly, the testicular veins were classified on the basis of their number (N) and site of drainage (D). The proposed classification facilitates identification, understanding, and reporting of variations of the testicular vessels by radiologists. It will also help surgeons to enhance the quality of their treatment. Clin. Anat. 31:854-869, 2018. © 2018 Wiley Periodicals, Inc.

A case of double inferior vena cava with renal, ovarian and iliac vein variation

We encountered a rare case of an anatomic variant of inferior vena cava (IVC) duplication with renal, ovarian and iliac vein variation in an 81-year-old Japanese female cadaver during a student dissection course of anatomy at Aichi Gakuin University School of Dentistry. The two IVCs ran upwards bilaterally to the abdominal aorta. The left IVC joined with the left renal vein (RV) to form a common trunk that crossed anterior to the aorta and ended at the right IVC. We detected a vein [interiliac vein (IiV)] connecting the two IVCs at the level of the aortic bifurcation. The IiV was formed by the union of two tributaries from the left IVC and a tributary from the left internal iliac vein (IIV) and ran obliquely upwards from left to right. Two right ovarian veins, arising separately from the ipsilateral pampiniform plexus, ran vertically in parallel to each other, and each one independently terminated at the right IVC and the right RV. Two right IIVs, connecting each other with small branches, ascended and separately joined the right external iliac vein. The right and left IIVs were connected to each other. These variations cause abnormal drainage, which could lead to clinical symptoms associated with the dysfunction of the vascular and urogenital systems. Here we describe the detailed anatomical features of the area and discuss the related anatomical and developmental aspects.

Adrenal venous sampling in a patient with left inferior vena cava

Adrenal venous sampling (AVS), although difficult, is recommended for patients with primary aldosteronism (PA) to diagnose the subtype. Recognizing anatomical variation is key to a successful AVS. We report on a patient with PA and left inferior vena cava (IVC) whose left adrenal vein drained directly into the IVC.

Variations of gonadal veins: embryological prospective and clinical significance

INTRODUCTION

An adequate knowledge of anomalies of gonadal veins will help the radiologists and surgeons in recognition and protection of these veins which play major roles in thermo-regulation that is essential for the efficient functioning of testis on which the survival of the human species depends.

AIM

The aim of this work is to present an analysis of the anatomical variations of gonadal veins. An effort has also been made to explicate the possible embryological model of development of such variants and to present the variable clinical aspects concerning them.

MATERIALS AND METHODS

Gonadal veins in 60 dissection room cadavers were examined for variations from the classic anatomic description.

RESULT

In the present study, out of 60 cases, male: female ratio was 2:1(40:20) in which no variation was found in ovarian veins. In the 18 (45%) cases, testicular veins showed variations which consist of duplication and atypical drainage.

DISCUSSION

Variations of drainage of gonadal vein are due to error of embryological development in venous shift and alteration in anastomotic channel of post-cardinal, supra-cardinal and sub cardinal veins.

CONCLUSION

The gonadal veins present numeric variations as well as variations in its site of drainage, which attributed to the various pathological conditions as varicocele and pelvic congestion syndrome, leading to infertility in patients. Hence, in -depth knowledge of these developmental anomalies of gonadal veins is important.

Morphological and surgical overview of adolescent testis affected by varicocele

Varicocele is a common pathology of the testis frequently associated with infertility. For its management, a fine morphological study of the testis, both macroscopically and microscopically, and an accurate choice of surgical procedure are mandatory. The present review focuses its attention on the anatomic substrates of adolescent varicocele and its pathophysiologic modifications. The comprehensive assessment of all the reported alterations should be considered by the clinician before deciding the type of treatment and the timing.

Anterior Spinal Surgery Involving Variant Vascular Anatomy: A Case Report

STUDY DESIGN

Case report of an anterior approach to the spine in the setting of variant vascular anatomy.

OBJECTIVE

To highlight the importance of evaluating vascular anatomy before anterior lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

A 62-year-old woman with idiopathic scoliosis had thoracolumbar fusion in adolescence and subsequently developed symptomatic sub-adjacent segment breakdown. Vascular complications may be encountered during anterior approaches to the spine. Variation in vascular anatomy may compound the difficulty of an already meticulous dissection.

RESULTS

A patient with idiopathic scoliosis who had thoracolumbar fusion in adolescence and subsequently developed symptomatic sub-adjacent segment breakdown. She underwent a 2-stage posterior/anterior procedure. During the anterior retroperitoneal approach, an anomalous left inferior vena cava was encountered that required tedious dissection for safe and adequate exposure of the lumbar spine.

CONCLUSIONS

When planning anterior lumbar spine surgery, careful review of the vascular anatomy on imaging should be performed. This will help prepare the surgeon for more complex or anomalous anterior anatomy. If atypical vascular anatomy is identified, consideration of a pathologic cause should be investigated.

Proposal for a new classification of variations in the iliac venous system based on internal iliac veins: a case series and a review of double and left inferior vena cava

There are many reports on variations in the inferior vena cava (IVC), particularly double IVC (DIVC) and left IVC (LIVC). However, no systematic report has recorded iliac vein (IV) flow patterns in the DIVC and LIVC. In this study, we examined IV flow patterns in both DIVC and LIVC observed during gross anatomy courses conducted for medical students and in previously reported cases. During the gross anatomy courses, three cases of DIVC and one case of LIVC were found in 618 cadavers. The IV flow pattern from these four cases and all other previously reported cases can be classified into one of the following three types according to the vein into which the internal iliac vein drained: the ipsilateral external IV; confluence of the ipsilateral external IV and IVC; and the communicating vein, which connects the IVC and the contralateral IVC or its iliac branch. This classification, which is based on the internal IV course, is considered to be useful because IV variations have the potential to cause clinical problems during related retroperitoneal surgery, venous interventional radiology, and diagnostic procedures for pelvic cancer.

A rare presentation of the double inferior vena cava with an anomalous retrocaval right ureter: embryogenesis and clinical implications

On dissection of the abdomen of an adult male cadaver, in addition to the normal inferior vena cava on the right side, an unusual venous channel which connected the left renal vein with the left common iliac vein was found; (probably the left inferior vena cava). The left testicular and the left suprarenal veins were opening into the left renal vein as usual. Other than this, a retrocaval ureter was found on the right side. The works of previous authors have highlighted the incidence of a venacaval duplication and its surgical implications, but here, we are presenting a unique case of a double inferior vena cava with an anomalous retrocaval ureter. A conglomeration of such vascular malformations is of immense surgical importance, and it is indicative of a grossly defective angiogenesis. Keeping in mind the clinical relevance of the variations which were observed, an attempt was made to explain them in the light of the embryogenic development.

Complication arising from a duplicated inferior vena cava following laparoscopic living donor nephrectomy: a case report

Selecting a kidney for living donor nephrectomy is driven by the tenet that donors are left with the higher functioning kidney. Traditionally, the left kidney is used because it has a longer renal vein, which aids anastamosis, and has an easier surgical approach. Anomalous left renal vasculature is not considered a contraindication to living donor nephrectomy. In the case of duplicated inferior vena cava, no specific considerations have been reported. We present a 42-year-old patient with infrarenal duplication of the vena cava who underwent laparoscopic living donor nephrectomy. His postoperative course was complicated by painful scrotal swelling necessitating multiple emergency room visits. Ultrasonography revealed bilateral hydroceles 5 weeks after surgery, which resolved with the use of a scrotal sling. Intraoperative ligation of a visibly dilated left gonadal vein was the likely etiology. Careful consideration should be taken in living donor nephrectomy in patients with duplication of inferior vena cava.

Left-sided and duplicate inferior vena cava: a case series and review

Left-sided and duplicate inferior vena cava (IVC) are two major anatomical variants within the spectrum of IVC malformations, both of which are developmental abnormalities of the supracardinal veins. Four clinical cases are described to highlight the computed tomographic appearances of these vascular malformations and provide novel data on venous dimensions. A systematic review of the recent literature (2000-2011) was conducted focusing on the anatomy, demographics, and associated pathology (congenital and acquired) of isolated left-sided and duplicate IVC. A total of 73 relevant articles were retrieved, consisting of case reports and small case series. The prevalence of left-sided IVC is about 0.1-0.4% and that for duplicate IVC about 0.3-0.4%; both anomalies show a slight male preponderance. In each condition, there are documented variations in the course and tributaries of the IVC. The clinical importance of these anomalies lies in three principal areas: the potential for misdiagnosis on imaging; technical difficulties during retroperitoneal surgery (particularly abdominal aortic aneurysm repair and live donor nephrectomy); and their significance in relation to the etiology and management of venous thromboembolism.

Right gonadal arteries passing dorsally to the inferior vena cava: embryological hypotheses

The right gonadal artery (RGA) usually arises from the anterior wall of the abdominal aorta below the level of the renal arteries and veins, passes ventrally to the inferior vena cava (IVC), and then runs obliquely downward to reach the pelvic cavity. In this study, we observed 59 Japanese cadavers and found that in eight of them (13.6%), the RGA's passed dorsally to the IVC. Together with the various courses of RGAs reported in the literature, we here divided the courses into four subtypes, due to the relationship to the left renal vein and the IVC, of superior, middle and lower types (L1 = ventrally, L2 = dorsal of IVC). Superior type was seen in 3.6%. Lower types were fount to in the most cases (L1: 83.5%, L2: 13.6%). The middle type was not realized. The classification of this variations make it easy to describe the RGA's passing below the level of the left renal vein. RGA can pass either ventrally or dorsally to the IVC. RGAs passing at or above the level of the left renal vein run dorsally but not ventrally to the IVC. The variations in the origin, course and branching of RGAs are attributed to development of the IVC.

Applied anatomic study of testicular veins in adult cadavers and in human fetuses

OBJECTIVES

Analyze the anatomic variations of the testicular veins in human cadavers and fetuses.

MATERIALS AND METHODS

One hundred male adult cadavers and 24 fetuses were studied. Four anatomic aspects were considered: 1) Number of testicular veins, 2) The local of vein termination, 3) Type and number of collaterals present and 4) Testicular vein termination angle.

RESULTS

Cadavers - Right side - One testicular vein occurred in 85% and 2 veins in 5% of the cases. There were communicating veins with the colon in 21% of the cases. Left side - One testicular vein occurred in 82%, two veins in 15%, three veins in 2% and four veins in 1% of the cases. There were communicating veins with the colon in 31% of the cases. Fetuses - Right side - One testicular vein occurred in all cases. This vein drained to the vena cava in 83.3% of the cases, to the junction of the vena cava with the renal vein in 12.5% and to the renal vein in 4.2%. There were communicating veins with the colon in 25% of the cases. Left side - One testicular vein occurred in 66.6% of the cases, and 2 veins in occurred 33.3%. Communicating veins with the colon were found in 41.6% of the cases.

CONCLUSION

The testicular vein presents numeric variations and also variations in its local of termination. In approximately 30% of the cases, there are collaterals that communicate the testicular vein with retroperitoneal veins. These anatomic findings can help understanding the origin of varicocele and its recurrence after surgical interventions.

Duplication of the inferior vena cava associated with other variations

Multiple vascular variations, including duplication of the inferior vena cava, double renal arteries and anomalies of the testicular blood vessels, were observed during dissection of the retroperitoneal region of a cadaver of an 87-year-old Japanese man. The right inferior vena cava arose from the union of right common iliac veins and a thinner interiliac vein. This interiliac vein ascended obliquely from right to left and joined the left common iliac veins to form the left inferior vena cava. The right and left inferior venae cavae were of approximately equal width. The right testicular vein consisted of medial and lateral venous trunks. The two venous trunks coalesced to form a single vein, which drained into the confluence of the right inferior vena cava and right renal vein. The left testicular vein was composed of the medial and lateral testicular veins, which drained into the left renal vein. Double renal arteries were seen bilaterally, which originated from the lateral aspects of the abdominal aorta. The right testicular artery arose from the right inferior renal artery and accompanied the lateral trunk of the right testicular vein running downwards. The left testicular artery arose from the ipsilateral inferior renal artery and ran downwards accompanied by the left lateral testicular vein. In addition, the bilateral kidneys showed multicystic changes.

Duplicate testicular veins accompanied by anomalies of the testicular arteries

Duplicate testicular veins associated with other anomalies of the testicular arteries were observed during dissection of the posterior abdominal wall in a 90-year-old Japanese male cadaver. The right testicular vein was composed of the medial and lateral testicular veins. The medial testicular vein drained into the inferior vena cava, whereas the lateral testicular vein drained into the confluence of the inferior vena cava and right renal vein. Several anastomosing branches were seen between the medial and lateral testicular veins. The left testicular vein was formed after the medial and lateral venous trunks joined and drained into the ipsilateral renal vein. The right testicular artery originated from the anterior surface of the abdominal aorta at the level of the left renal artery, passed posterior to the inferior vena cava, and accompanied the right lateral testicular vein running downwards. The left testicular artery arose from the abdominal aorta at a level of 5 cm below the origin of the right testicular artery, and then ran downwards accompanied by the medial trunk of the left testicular vein.

Unusual drainage of the testicular veins

An unusual drainage of the testicular veins was found during routine cadaveric dissection. Specifically, the lateral division of each testicular vein on both left and right sides was found to drain into the subcostal veins. No other anomalies of the veins of the abdomen were found. Knowledge of the many anomalies that can potentially occur in the abdominal region is necessary in interpretation of images of this anatomical area. Additionally, knowledge of these variations is important surgically; for example, anomalous veins that ought to be ligated during surgery for varicocele go unnoticed and result in recurrence of the varicocele.