Thoracic renal artery: a rare variant. A case study and literature review

Unraveling Renal Arteries Morphogenesis from Tridimensional Human Embryos Reconstruction

BACKGROUND

During human morphogenesis, the definitive kidneys derive from the metanephros during Carnegie Stage 14 to 23. The pronephros and the mesonephros develop previously and successively to finally lead to the formation of the urinary tract. Renal vascularization, first described in 1912 by Félix using a "ladder theory" model, is highly variable and current available morphogenesis descriptions do not explain all reported anatomical variations. The aim of this work was to study the morphogenesis of the human metanephros and its vascularization by three-dimensional reconstructions of human embryos.

METHODS

Histological sections of 23 human embryos from the Carnegie Collection and 5 human embryos from the French collection (Carnegie stages 14 to 23) were completely digitalized and reconstructed in three dimensions using specific softwares and then analyzed by descriptive method using manual annotation.

RESULTS

In all studied embryos, the mesonephric arteries did not reach the metanephros irrespective to the position of the metanephros during its cranial ascent. Before the end of the cranial metanephros migration (15 embryos), at the level of the aorto-iliac bifurcation, a "primitive" vascularization was shown in 9 of them. The renal artery originated from the primitive iliac arteries for 8 embryos and from the inferior mesenteric artery in one embryo. Further, a capillary cluster emerging from the lateral wall of the aorta and extending toward the metanephros was found in 2 embryos (Carnegie stages 21 and 22). This may correspond to a phenomenon of neoangiogenesis responsible of the definitive renal artery.

CONCLUSIONS

The present study reported the morphogenesis of human renal arteries between Carnegie stages 14 and 23 using an original method of tridimensional computerized reconstructions of historical human embryos. Some original findings, in contradiction with the original Felix's description, may explain the most frequently reported anatomical variations.

Supradiaphragmatic origin of the right renal artery: a case report

Renal arteries are the main blood supply to the kidneys. They originate from the abdominal aorta at the level of the first and second lumbar vertebrae. However, variations in their origin are common. Therefore, studying renal arteries before any surgical intervention such as renal transplant surgery, conservative or radical renal surgeries, renal trauma, and others, is crucial to avoid undesirable avoidable complications or morbidities. Herein, we report a case of an isolated right supradiaphragmatic renal artery that was discovered incidentally in a 66-year-old female patient with normal blood pressure.

Supradiaphragmatic origin of the renal artery; frequency on contrast-enhanced MR imaging

PURPOSE

The purpose of this study was to evaluate extremely rare cases of supradiaphragmatic origin of the renal artery, with magnetic resonance (MR) imaging findings.

METHODS

The study included 9 patients diagnosed with supra-diaphragmatic originating renal artery between 2010 and 2017. The patients were 7 females and 2 males with a mean age of 58.25 years (range, 41-71 years). MR imaging was applied to all patients.

RESULTS

In 2 patients, lumen loss was of a moderate degree, and mild in 3 patients. Renal artery stenosis was not observed in the remaining 4 patients. None of the patients had advanced luminal stenosis. The distance of the renal arteries to the diaphragmatic crus was 24 mm at the longest and 8 mm at the shortest. Congenital anomaly was found in 6 patients. Of the 9 patients, 7 had concomitant hypertension, and 2 had no history of hypertension.

CONCLUSIONS

The anomaly of supradiaphragmatic origin of the renal artery is rare but may be associated with renal artery stenosis, which may then result in hypertension. The clinician should investigate renal artery origin anomalies and renal artery compression syndrome in hypertensive cases where the cause cannot be explained.

Thoracic Origin of Single Right Renal Artery: Some Interesting Facets

Two cases of thoracic origin of the right renal artery, arising from the level of D11 vertebrae detected on an incidental computed tomography examination are reported. A brief review of embryology is presented. Simultaneous variation of the origin of the right inferior phrenic artery is highlighted as a unique feature of our cases. The importance of this relatively uncommon anomaly in the clinical context is discussed.

Thoracic renal artery: a rare case of the renal artery originating from the thoracic aorta and literature review

We report a very rare case of the right renal artery originating from the thoracic aorta. A 37-year-old man visited our hospital for follow-up regarding a gallbladder polyp that had been detected incidentally via ultrasonography as part of a clinical survey. Contrast-enhanced computed tomography revealed incidentally that the right renal artery originated from the thoracic aorta at the level of the 11th thoracic vertebra. No excess right renal artery was found arising from the abdominal aorta, and a normal left renal artery was observed. Although this anomaly is very rare, urological and thoracic surgeons should be aware of this condition, in order to provide appropriate surgical interventions.