retroperitoneoscopic nephrectomy , although rst reported in 1969 , did not become popular until gaur 's demonstration of the elegant technique of atraumatic balloon dissection of the retroperitoneum . with all the advantages of maintaining an extraperitoneal surgical field , and with prompt access to the great vessels and renal vasculature , retroperitoneoscopic nephrectomy provides excellent outcomes with minimal morbidity . the aim of this study was to report the initial experience , learning curve and outcome of retroperitoneoscopic nephrectomy by novices under a mentored approach . the series included four novice urologists ( two chief residents and two recently qualified consultants ) . they had only assisted in some transperitoneal laparoscopic nephrectomy ( < 10 cases ) during their residency and had never assisted / performed retroperitoneoscopic nephrectomy . the data from the forty retroperitoneoscopic nephrectomies performed by each of them ( total 160 cases ) between may 2013 and august 2015 were reviewed after permission from all surgeons . to assess the learning curve for retroperitoneoscopic nephrectomy , we studied changes in key operative parameters ( operative time , blood loss , complications , nonprogression by novices , conversion rate ) as a function of the case number . all patients who underwent nephrectomy for nonfunctioning and very poorly functioning ( creatinine clearance < 10 ml / min ) kidney secondary to various benign diseases were included in the study . patients with pyonephrosis ( thick pus through percutaneous nephrostomy [ pcn ] drainage ) , genitourinary tuberculosis , xanthogranulomatous pyelonephritis ( on imaging ) , autosomal dominant polycystic kidney disease , history of open renal surgery were excluded from the study . all these conditions lead to significant scarring and leads to increased operative difficulty , therefore these were not operated by novices . independent t - test has been used to calculate statistically significant value , i.e. p value . during the implementation of retroperitoneoscopic nephrectomy at our institution , we adopted an approach that we hoped would allow us to minimize the morbidity associated with the learning curve . for all novice surgeons , we use a standardized protocol that includes an initial phase of observation and assistance to the mentor for 912 months in retroperitoneoscopic donor and simple nephrectomy ( 2030 cases ) , followed by operating independently under the supervision of a mentor . in this phase , the novice surgeon was made familiar with the basics of retroperitoneoscopy through theoretical as well as practical knowledge of the procedure . this incorporated everything from patient positioning to wound closure , with continual interactive teaching by the mentor . teaching included patient positioning , selection of instrumentation , appropriate surgeon and camera assistant positioning , the steps to achieve retroperitoneal access , techniques to obtain optimal clear vision , instrument manipulation , and advice on how to achieve dexterity throughout the surgery . standard steps of surgery were followed which includes three port insertion after retroperitoneal dissection , ureter identification , hilar dissection , and kidney mobilization . we believe that familiarity with technique and standard steps enhance efficiency during retroperitoneoscopic surgery and has the potential to shorten the duration of the learning curve . after this training , operating surgeon was assisted by fellow resident , junior consultant or an experienced nursing staff . the primary port was placed using a 1.5 cm incision below the 12 rib at mid axillary line , deepened down to the thoracolumbar fascia . a retroperitoneal space was created using an indigenous balloon ( tying the finger of a glove over a k-90 catheter ) and inflating it with saline up to 500700 ml . second port ( 10 mm ) at renal angle , at least 3 finger breadths distant from first port and third port ( 5 mm ) 3 finger breadths anterior to first port , forming a straight line with the other ports . after port insertion , standard surgical steps in sequence followed , ureter identificationhilar vessel dissection and divisionkidney mobilization . we evaluated and compared key operative parameters such as operative time , complications and conversions for each novice surgeon and the number of cases taken to reach proficiency . during the implementation of retroperitoneoscopic nephrectomy at our institution , we adopted an approach that we hoped would allow us to minimize the morbidity associated with the learning curve . for all novice surgeons , we use a standardized protocol that includes an initial phase of observation and assistance to the mentor for 912 months in retroperitoneoscopic donor and simple nephrectomy ( 2030 cases ) , followed by operating independently under the supervision of a mentor . in this phase , the novice surgeon was made familiar with the basics of retroperitoneoscopy through theoretical as well as practical knowledge of the procedure . this incorporated everything from patient positioning to wound closure , with continual interactive teaching by the mentor . teaching included patient positioning , selection of instrumentation , appropriate surgeon and camera assistant positioning , the steps to achieve retroperitoneal access , techniques to obtain optimal clear vision , instrument manipulation , and advice on how to achieve dexterity throughout the surgery . standard steps of surgery were followed which includes three port insertion after retroperitoneal dissection , ureter identification , hilar dissection , and kidney mobilization . we believe that familiarity with technique and standard steps enhance efficiency during retroperitoneoscopic surgery and has the potential to shorten the duration of the learning curve . after this training , operating surgeon was assisted by fellow resident , junior consultant or an experienced nursing staff . the primary port was placed using a 1.5 cm incision below the 12 rib at mid axillary line , deepened down to the thoracolumbar fascia . a retroperitoneal space was created using an indigenous balloon ( tying the finger of a glove over a k-90 catheter ) and inflating it with saline up to 500700 ml . second port ( 10 mm ) at renal angle , at least 3 finger breadths distant from first port and third port ( 5 mm ) 3 finger breadths anterior to first port , forming a straight line with the other ports . after port insertion , standard surgical steps in sequence followed , ureter identificationhilar vessel dissection and divisionkidney mobilization . we evaluated and compared key operative parameters such as operative time , complications and conversions for each novice surgeon and the number of cases taken to reach proficiency . during the implementation of retroperitoneoscopic nephrectomy at our institution , we adopted an approach that we hoped would allow us to minimize the morbidity associated with the learning curve . for all novice surgeons , we use a standardized protocol that includes an initial phase of observation and assistance to the mentor for 912 months in retroperitoneoscopic donor and simple nephrectomy ( 2030 cases ) , followed by operating independently under the supervision of a mentor . in this phase , the novice surgeon was made familiar with the basics of retroperitoneoscopy through theoretical as well as practical knowledge of the procedure . this incorporated everything from patient positioning to wound closure , with continual interactive teaching by the mentor . teaching included patient positioning , selection of instrumentation , appropriate surgeon and camera assistant positioning , the steps to achieve retroperitoneal access , techniques to obtain optimal clear vision , instrument manipulation , and advice on how to achieve dexterity throughout the surgery . standard steps of surgery were followed which includes three port insertion after retroperitoneal dissection , ureter identification , hilar dissection , and kidney mobilization . we believe that familiarity with technique and standard steps enhance efficiency during retroperitoneoscopic surgery and has the potential to shorten the duration of the learning curve . after this training , operating surgeon was assisted by fellow resident , junior consultant or an experienced nursing staff . the primary port was placed using a 1.5 cm incision below the 12 rib at mid axillary line , deepened down to the thoracolumbar fascia . a retroperitoneal space was created using an indigenous balloon ( tying the finger of a glove over a k-90 catheter ) and inflating it with saline up to 500700 ml . second port ( 10 mm ) at renal angle , at least 3 finger breadths distant from first port and third port ( 5 mm ) 3 finger breadths anterior to first port , forming a straight line with the other ports . after port insertion , standard surgical steps in sequence followed , ureter identificationhilar vessel dissection and divisionkidney mobilization . we evaluated and compared key operative parameters such as operative time , complications and conversions for each novice surgeon and the number of cases taken to reach proficiency . the most common cause for nonfunctioning kidney was stone disease followed by pelviureteric junction obstruction . other causes were ureteral strictures , vesicoureteral reux , obstructed megaureter , renal dysplasia , renovascular hypertension , etc . some of the patients had a pcn placed 46 weeks before nephrectomy for infected hydronephrosis or to assess the salvageability of the kidney . since the creatinine clearance did not improve ( < 10 ml / min ) , these patients underwent retroperitoneoscopic nephrectomy . the demographic and diagnosis of cases operative parameters and complication retroperitoneoscopic nephrectomy was successfully completed by novices in 88.1% ( 141/160 ) of the patients . nine cases ( 5.6% ) required mentor help because of non progression and ten cases ( 6% ) required conversion to open nephrectomy . operative parameters and complications the reasons for conversion were mainly elective , secondary to adhesions ( in nine cases ) , only one emergency due to inferior vena cava ( ivc ) tear ( one case ) . , hilar dissection was done , and the renal vessels were secured , but safe kidney removal was difficult due to adhesion to vital structures : duodenum , ivc , etc . there was an ivc injury during hilar dissection of right side nephrectomy which required conversion to open surgery for repair of the ivc rent . the most common minor complications ( clavien grade i ) were peritoneal rent in 27 patients ( 16.8% ) , which was managed by inserting a veress needle into the peritoneum to reduce the intraperitoneal pressure . puncture and spillage of renal contents occurred in 11 ( 6.8% ) patients . the retroperitoneoscopic approach has an advantage in such patients and prevents contamination of the peritoneal cavity . subcutaneous emphysema developed in 15 patients ( 9.3% ) , but in none of the patients was it significant enough to cause hypercarbia or necessitate conversion . only one case with ivc injury required blood transfusion ; the rest had minimal blood loss was very low ( 2060 ml ) and therefore did not require transfusion . for self - evaluation , we compared the initial twenty cases of all surgeons with their next twenty cases . all surgeons had a significant reduction in operative time by as much as 60 min . furthermore , comparing ten consecutive cases of each surgeon , there was some intersurgeon variation in the learning curve . it was found that for half of surgeons ( surgeon a and d ) , median operative time reduced significantly by 40 min approximately ( from 200 to 160 min ) after first twenty cases , while operative time of one surgeon ( surgeon b ) stabilized rapidly after first ten case , another surgeon ( surgeon c ) took thirty cases . however importantly , all surgeons showed a progressive reduction in the median operative time across consecutive sets of ten cases [ graph 1 ] . furthermore , some variability in operative time persisted and a few cases of all surgeons , even in the last sets of patients , had very long operative time . this may be because no two nephrectomies were ever the same and operative time was influenced by operative complexity because of inflammatory adhesion and bulk of perinephric fat . urologists have historically favored a retroperitoneal approach for open simple nephrectomy . on the contrary , for laparoscopic simple nephrectomy the retroperitoneal approach has several advantages over the transperitoneal approach , including ease of direct access to the kidney through the creation of the retroperitoneal space with a decreased risk of injury to intra - abdominal organs such as the bowel , liver , and spleen . other advantages of the retroperitoneal approach are that previous abdominal surgery is not a contraindication , and the risk of postoperative adhesive intestinal obstruction is avoided . the smaller working space , relative lack of anatomic landmarks , trocar spacing and difficulty in orientation for beginners are some of the disadvantages of the retroperitoneal approach . modi et al . in the initial phase of learning had reported a higher conversion rate , longer operative time , and more complications . during the last 10 years , have also reported retroperitoneoscopic nephrectomy for various technically challenging scenarios such as pyonephrotic kidneys ( with a success rate of 86% ) , nephrocolonic fistula due to the tuberculous nonfunctioning kidney , pretransplant nephrectomy , pyonephrotic nonfunctioning moiety of horseshoe kidney , and crossed fused ectopic kidney . this study evaluates the learning curve of residents / novices when trained by experienced mentors . here , the novice surgeon had the benefit of using techniques already refined by their mentors . furthermore , the initial orientation phase facilitates mentors , in making the trainee well versed with all standardized surgical steps , along with simultaneous discussion , thus clearing the doubts related to anatomical details . this is not feasible by just reading the books or reviewing of video tapes . in this study , the median operative time of all surgeons reduced with increased surgical experience . minor complications were not signicant enough to either hamper the successful completion of the procedure or alter the outcome . thus , there was some learning curve effect observed only in operative time with longer operative time in initial cases of all surgeons . however , the overall operative complications were minimal , showing that this learning curve had no deleterious effects on patient care . with our large experience in performing retroperitoneoscopic nephrectomies over a decade , we would like to like to propose certain tips in the initial part of the learning curve that is given in box 1 . the present series represents the effectiveness of training of novices in retroperitoneoscopic nephrectomy by a responsible team with the standard protocol and surgical steps . through effective mentoring , the steep learning curve associated with retroperitoneoscopic nephrectomy has been overcome , making it the standard of care for nephrectomy at our institute .
introduction : between the two techniques of laparoscopic nephrectomy , retroperitoneoscopy has certain distinct advantages over transperitoneal access but may be a more difficult technique to learn . 
 we present our experience of training novices in retroperitoneoscopic nephrectomy with a good outcome , making it a standard of care for nephrectomy at our institute.methods:the aim of this study was to report the initial experience , learning curve , and outcome of retroperitoneoscopic nephrectomy by novices under a mentored approach . 
 the series included four novice urologists . 
 the data from the initial forty retroperitoneoscopic nephrectomies performed by each of them were reviewed.results:retroperitoneoscopic nephrectomies were successfully completed by novices in 88.1% ( 141/160 ) of the patients . 
 nine cases ( 5.6% ) required the mentor 's help because of nonprogression , and ten cases ( 6% ) required conversion to open nephrectomy . 
 the median operative time of all surgeons decreased with increased surgical experience . 
 there was some intersurgeon variation in the learning curve ranging from 10 to 30 cases , but all surgeons showed a significant reduction in operative time across consecutive sets of ten cases . 
 seven cases required mentor help in the initial series ( 7/80 ) and only two in later half of cases ( 2/80 ) . 
 all minor complications were also significantly less in the later series.conclusions:the present series represents the effectiveness of training in retroperitoneoscopic nephrectomy of novices by a responsible team and with the standard protocol and surgical steps . through effective mentoring , the steep learning curve associated with retroperitoneoscopic nephrectomy has been overcome , making it standard of care for nephrectomy at our institute .