the patient presented with a 12-month history of right flank pain and a right abdominal mass . the preoperative evaluation revealed renal malrotation , hydronephrosis , decreased renal function , and presumed ureteropelvic junction obstruction . by using a transperitoneal laparoscopic approach , an enlarged ovarian vein was identified as the cause of the ureteral obstruction . the patient 's postoperative course was unremarkable , and she was discharged from the hospital on the second postoperative day . at 3-months follow - up , a careful preoperative evaluation is required to exclude other causes of ureteral obstruction . by using a laparoscopic approach , the ureter and obstructing vessel were readily identified to effectively treat the patient . with the minimally invasive approach ovarian vein syndrome ( ovs ) is an uncommon but recognized cause of ureteral obstruction and flank pain . most cases are related to changes of pregnancy , but the syndrome can also present in a chronic form following pregnancy . typically , ovs occurs in thin females with a right - sided predilection . this case highlights a unique presentation , the preoperative evaluation , and laparoscopic management of ovarian vein syndrome . a 43-year - old female presented with a 12-month history of right flank pain and a palpable right abdominal mass . in addition , she previously had a benign cyst surgically removed from her right ovary . she denied having a history of gross hematuria , stones , or urinary tract infection . on examination , the patient was very thin and had a palpably visible mass in the right mid - abdomen that was mildly tender to palpation . a diuretic renal scan revealed a severe obstruction of the right kidney ( t1/2 = 84 minutes ) and a differential function of 26% . a right retrograde pyelogram revealed dilation and tortuosity of the very proximal ureter consistent with a presumed ureteropelvic junction ( upj ) obstruction . intravenous urogram completed before ( a ) and after ( b ) laparoscopic division of the ovarian vein . the working diagnosis was ureteropelvic junction obstruction ; and given the decreased differential function of the right kidney , presence of renal malrotation , and findings demonstrated on the retrograde pyelogram , the patient was offered laparoscopic treatment rather than endopyelotomy . in preparation for the laparoscopic procedure , trocars were placed at the umbilicus ( 12 mm ) , 5.0 cm above and medial to the iliac crest ( 5 mm ) , and midway between the umbilicus and xiphoid process ( 12 mm ) . the colon was reflected medially , and dissection of the right ureter and ureteropelvic junction was completed . an enlarged right ovarian vein , approximately 2.0 cm in diameter , was identified externally compressing the anterolateral aspect of the ureter near the ureteropelvic junction ( figure 2 ) . the ovarian vein was carefully dissected from the ureter and divided with a vascular stapler ( figure 2 ) . the renal malrotation was not contributing to the obstruction ; therefore , nephropexy was not performed . the postoperative recovery was unremarkable and the patient was discharged on the second postoperative day . the urinary stent was removed 3 weeks after surgery . at 3-months follow - up , the patient was completely pain free , and an intravenous pyelogram revealed significantly decreased hydronephrosis and no evidence of upj obstruction ( figure 1 ) . intraoperative appearance of the ureteropelvic junction and ovarian vein before ( a ) , during dissection ( b , c ) , and after ( d ) division with the laparoscopic stapling device . a preoperative diagnosis of ovs is warranted only after more common causes of ureteral obstruction have been excluded . the traditional treatment for this condition has been open excision of the ovarian vein and ureterolysis . for the patient described in this report , first , based on the preoperative evaluation , the presumed diagnosis was ureteropelvic junction obstruction . because the right kidney had decreased differential function , a laparoscopic approach as opposed to endopyelotomy was the favored method for repair . poor renal function has been reported to adversely impact successful treatment of ureteropelvic junction obstruction . renal anomalies can be associated with a higher likelihood of obstruction secondary to crossing vessels . in addition , a laparoscopic approach permits careful assessment of the periureteral anatomy and the possibility of completing a dismembered pyeloplasty if warranted . finally , use of a laparoscopic approach may limit the risk of hemorrhagic complications if a vessel is incised . in 2 large series of patients treated with laparoscopic pyeloplasty a 3% to 4% incidence of hemorrhagic complications necessitating blood transfusion , embolization , or both , is reported with endopyelotomy . in fact , schwartz and stoller recently reported significant hemorrhage associated with laceration of an obstructing ovarian vein during acucise endopyelotomy . although the traditional treatment for ovs is open surgery , this case represents the second report of laparoscopic division of ovarian veins . in another case report unique to this case is the associated renal malrotation and radiographic findings that favored a diagnosis of ureteropelvic junction obstruction rather than ovs . because of the decreased differential function of the right kidney and presumed ureteropelvic junction obstruction , this approach was fortuitous as it provided a better assessment of the periureteral anatomy and identification of the ovarian vein . computerized tomography is not routinely obtained for the evaluation of presumed primary upj obstruction , but given the history of malrotation in this case , such an evaluation would probably have identified the obstructing ovarian vein and prompted similar treatment recommendations . in conclusion , ovarian vein syndrome is a rare cause of ureteral obstruction . to exclude more common causes of ureteral obstruction the presence of aberrant vessels and ureteropelvic junction obstruction is much more common in anomalous kidneys than ovs . for such high - risk patients with normal differential function , the preoperative evaluation should include an assessment of crossing vessels prior to treatment with endopyelotomy . for patients with decreased renal function , computerized tomography may be helpful ; however , endopyelotomy success is reduced and laparoscopic exploration of the upj is recommended because it permits rapid identification of the cause of obstruction and , in this case , safe effective treatment of ovs .
background : ovarian vein syndrome is a rare cause of ureteral obstruction . in this report , we describe an unusual presentation of the syndrome successfully treated with laparoscopic techniques.methods:the patient presented with a 12-month history of right flank pain and a right abdominal mass . 
 the preoperative evaluation revealed renal malrotation , hydronephrosis , decreased renal function , and presumed ureteropelvic junction obstruction.results:by using a transperitoneal laparoscopic approach , an enlarged ovarian vein was identified as the cause of the ureteral obstruction . 
 the ovarian vein was divided with a laparoscopic stapler . 
 the patient 's postoperative course was unremarkable , and she was discharged from the hospital on the second postoperative day . at 3-months follow - up , 
 the patient was completely asymptomatic without evidence of obstruction.discussion:ovarian vein syndrome remains a rare diagnosis of exclusion . 
 a careful preoperative evaluation is required to exclude other causes of ureteral obstruction . by using a laparoscopic approach , 
 the ureter and obstructing vessel were readily identified to effectively treat the patient . with the minimally invasive approach 
 , postoperative recovery and patient quality of life were improved .