left - sided inferior vena cava ( ivc ) is an unusual abnormality that may be clinically significant during renal surgery . we report the unique case of a patient with a centrally located left renal mass who underwent laparoscopic radical nephrectomy . during the hilar dissection the patient was noted to have a left - sided inferior vena cava with multiple renal veins and anomalous tributaries . the embryology of a left - sided inferior vena cava is reviewed , and the safety and feasibility of a laparoscopic approach is discussed . unexpected vascular anomalies may increase the risk of hemorrhage and necessitate conversion to open nephrectomy . we report the case of a major inferior vena cava ( ivc ) anomaly encountered during laparoscopic nephrectomy and discuss its embryogenesis and management . computed tomography revealed a 4-cm enhancing lesion located centrally within the left kidney ( figure 1 ) . laparoscopic left radical nephrectomy was planned and upon hilar dissection , the ivc was encountered without visualization of the aorta , confirming its left - sided orientation . in addition , 3 renal veins were noted , as was a left gonadal vein that drained directly into the ivc ( figure 2 ) . an aberrant vein was exposed that bridged the gonadal vein and the most caudal of the supernumerary renal veins . prior to dissection of the renal artery , the caudal renal vein , gonadal vein , and bridging anomalous vein were ligated and transected . abdominal ct scan illustrates the ivc as it courses from the normal anatomic position to the left - sided position : ( a ) ivc in right - sided anatomical position ( thick arrow ) ; ( b ) ivc crossing anterior to the aorta ( thick arrow ) ; ( c ) ivc crossing anterior to the aorta ( thick arrow ) and main left renal vein ( thin arrow ) . left renal mass is noted in a central location ; ( d ) ivc in left - sided position ( thick arrow ) and second left renal vein ( thin arrow ) . view of cephalad ( left ) and caudad ( right ) aspect of ivc ; kidney ( out of frame ) is located towards top of image . left gonadal vein drains into the left - sided ivc . two of the 3 left renal veins are noted . bridging vein between the main renal vein and gonadal vein is noted . the laparoscopic approach has become an accepted standard for extirpative renal surgery , with less postoperative pain , decreased hospital stay , and shorter convalescence compared with that of open surgery . colombo et al reported that hemorrhage continues to be the most common intraoperative complication of laparoscopic surgery , occurring at a rate of 2.3% and requiring open conversion in 0.9% of cases . preoperative knowledge of pertinent vascular anatomy is essential during laparoscopic renal surgery to avoid potential complications . to our knowledge , this is among the initial reported cases of a left - sided inferior vena cava encountered during laparoscopic radical nephrectomy . left - sided ivc is an abnormality that occurs at a prevalence of 0.2% to 0.5% and is usually asymptomatic . although commonly an incidental finding , it becomes clinically significant when it is mistaken for paraaortic lymphadenopathy or the main renal vein . the embryonic development of ivc involves the emergence and selective regression of 3 pairs of embryonic veins : the posterior cardinal , subcardinal , and supracardinal veins . anomalies of the postrenal segment of the ivc include retrocaval ureter , duplicated ivc , and left - sided ivc . a left - sided ivc is caused by persistence of the left supracardinal vein with regression of the right supracardinal vein . the left subrenal ivc then joins the left renal vein and crosses anterior to the aorta where it unites with the right renal vein . as a result , renal venous development results from anastomosis of the subcardinal and supracardinal veins . during normal development , multiple persisting renal veins is the most common anomaly of the venous developmental system with a prevalence ranging from 9% to 20% . the main clinical significance of this finding is the risk of iatrogenic injury during renal surgery . when a left - sided ivc is encountered , the surgeon must be suspicious of other anomalies . in our patient , 3 renal veins , careful examination of preoperative radiographic imaging is mandatory in the diagnosis of a left - sided ivc . case reports have described this phenomenon during laparoscopic live donor nephrectomy without adverse effects . in our experience , this anomaly may be more readily apparent when evaluating patients with higher resolution imaging . in accordance with other reports , our case demonstrates that laparoscopic radical nephrectomy can be successfully performed without complications in the presence of a left - sided ivc .
background : left - sided inferior vena cava ( ivc ) is an unusual abnormality that may be clinically significant during renal surgery.methods:we report the unique case of a patient with a centrally located left renal mass who underwent laparoscopic radical nephrectomy . during the hilar dissection , unusual vascular anatomy was encountered . 
 the patient was noted to have a left - sided inferior vena cava with multiple renal veins and anomalous tributaries . 
 laparoscopic radical nephrectomy was performed without complication.discussion:the embryology of a left - sided inferior vena cava is reviewed , and the safety and feasibility of a laparoscopic approach is discussed .