partial cystectomy is a bladder - preserving operation that has been utilized in both benign and malignant diseases .
it is indicated in patients who have good bladder capacity and in cases of a solitary tumor in the bladder dome , a urachal tumor , or a tumor within the diverticulum with no concomitant carcinoma in situ ( cis ) .
the advantages of partial cystectomy are minimizing the complications related to radical cystectomy in addition to preserving bladder function and erectile function .
laparoscopic partial cystectomy is performed in cases of not only benign bladder masses , such as leiomyoma , pheochromocytoma , and endometriosis , but also in cases of malignant bladder tumors and urachal remnants [ 4 - 6 ] .
more recently , robot - assisted laparoscopic surgery has emerged in the urology field , especially in the treatment of prostate cancer and bladder cancer . in parallel with the positive results of robot - assisted laparoscopic prostatectomy and robot - assisted laparoscopic radical cystectomy
, we anticipated similar benefits , including decreased morbidity , shortened operative time , and shortened hospital stay , from performing robot - assisted laparoscopic partial cystectomy ( rlpc ) on urachal diseases .
the urachus is a three - layered embryological structure that connects the allantois to the fetal urinary bladder . the urachus changes into a fibrous band after birth .
various urachal abnormalities , such as urachal sinus , urachal cyst , vesicourachal diverticulum , and patent urachus , may lead to abdominal pain , umbilical drainage , or urachal cancer [ 9 - 11 ] .
because of the poor prognosis of urachal cancer with aging , urachal excision with partial cystectomy should be performed at diagnosis .
herein , we report our initial experience of 4 cases of rlpc performed on urachal diseases and evaluate the perioperative and pathologic results .
four patients underwent rlpc between june 2009 and december 2009 by a single surgeon using the da vinci - s robotic system ( intuitive surgical , sunnyvale , ca , usa ) .
two men and two women , with a mean age of 51.59.3 years and a mean body mass index ( bmi ) of 24.41.7 kg / m underwent the operation . each patient presented with gross hematuria , dysuria , and mucous secretion in the urine .
patient 1 had hypertension and patient 2 had a history of trans - abdominal hysterectomy .
preoperative abdominal computed tomography ( ct ) scans revealed a solid mass in the dome area of the urinary bladder ( fig .
the patient was placed in the lithotomy position with both arms fixed against the body under general anesthesia .
foley catheter was inserted in the urethra , and pneumoperitoneum with carbon dioxide was established by using a veress needle at a point 2 cm superior to the umbilicus .
the placement of the trocars is similar to that in robot - assisted laparoscopic radical prostatectomy but 2 cm superior to ensure that the urachus is accessible .
the first robotic arm 8 mm trocar was placed 8 cm left laterally and the second robotic arm 8 mm trocar was placed 8 cm right laterally to the 12 mm camera port .
the third robotic arm 8 mm trocar was placed 8 cm laterally to the second robotic arm port .
the 12 mm assistant port was placed 8 cm laterally to the first robotic arm port , and the 5 mm assistant suction port was placed 8 cm superior to the camera port and the first robotic arm port ( fig .
the patient was placed in the 30 trendelenburg position and the robotic system was docked to the patient .
the urinary bladder was filled with 200 cc of air , and a transperitoneal approach was performed with the 0 robotic camera with the use of monopolar scissors and a bipolar maryland dissector .
any bowel adhesions were lysed with the monopolar scissors and the medial umbilical ligament was dissected .
the bladder was released from the surrounding structure to permit identification of the bladder margins .
after the cranial dissection into retzius ' space , the mass of the dome site was identified , and a cystotomy was performed with the monopolar scissors at a distance of 2 cm from the margin of the mass ( fig .
the bladder was closed in two layers with watertight running sutures made with 2 - 0 vicryl .
a jackson - pratt drain was positioned in the retzius ' space , and the specimen was removed from the camera port .
a nasogastric tube was removed 1 day after surgery , and an oral liquid diet was started simultaneously .
the mean operative time , including trocar placement as well as robotic docking and closure , was 198 minutes ( range , 130 - 260 minutes ) .
the mean console time was 111 minutes ( range , 70 - 150 minutes ) .
the mean estimated blood loss was 155 ml . there were no conversions to open surgery .
the mean hospital stay was 6 days ( range , 4 - 7 days ) .
drain removal was performed at postoperative day 2.5 ( range , 2 - 3 days ) .
each patient underwent postoperative cystography on day 7 postoperatively , and no patients had evidence of extravasation .
two patients had the foley catheter removed at that time , and the other two patients had the foley catheter removed as outpatients after discharge on postoperative day 7 .
there were no major complications . a 1-month postoperative image of the port site is presented in fig .
the operative results and the final pathology report of each case are presented in table 1 .
two patients were diagnosed with a urachal cyst , whereas the other two patients were diagnosed with patent urachus and urachal cystadenoma , respectively .
in the urology field , rassweiler et al initially performed ralp in 2001 with the da vinci robotic system . recently , robot - assisted laparoscopic prostatectomy has been performed worldwide , and it can overcome the limitations of open radical prostatectomy and laparoscopic radical prostatectomy .
many urologists have expressed interest in robotic surgery because of its comparable perioperative results to open surgery and conventional laparoscopic surgery , which have steep learning curves .
after the application of a robot - assisted laparoscopic approach to prostate cancer , various operations have been successfully performed by use of robotic systems . to date , robot - assisted laparoscopic radical cystectomy has been performed in many medical centers .
the advantages of robot - assisted laparoscopic radical cystectomy include easier dissection and mobilization , which rlpc can also obtain .
our experience with robotic surgery for prostate cancer , kidney cancer , and ureteropelvic junction stricture acclimmated us to controlling the instruments and practicing suture techniques before performing rlpc .
myer et al reported their initial experiences of 5 serial cases of robot - assisted bladder diverticulectomy , and a similar report was published by meeks et al about robot - assisted bladder diverticulectomy in pediatric patients . according to those reports ,
recently , tareen et al reported their initial experiences with robot - assisted laparoscopic partial cystectomy and diverticulectomy assisted by simultaneous transurethral incision . in the report of tareen
et al , partial cystectomy was performed in 2 cases and diverticulectomy was performed in 2 cases .
tareen et al reported the feasibility of rlpc and the advantages of the precise suture technique and enhancement of surgeon visibility . in our study
, rlpc was performed by a single surgeon using a transperitoneal approach . in the case of a dome area mass ,
the advantages of the preperitoneal approach are minimizing intra - abdominal complications and preventing intra - abdominal spillage .
the use of a transperitoneal approach to secure the margin of the excision site and to suture the excision site of the bladder is superior to the use of a preperitoneal approach , however . in performing partial cystectomy , making an incision with adequate surgical margins and minimizing
after detection of the lesion , we made a 1 cm incision at a 2 cm distance from the lesion .
after the robotic camera was inserted into the incision site , the bladder lesion was detected and an adequate surgical margin was secured .
the dome site lesion was excised with a 2 cm safety margin under robotic vision by use of monopolar scissors . in our cases ,
an en bloc excision with umbilectomy was not performed because of the small size of the mass with no evidence of lymphadenopathy in the preoperative ct scan or in intraoperative findings . however , the urachus , involving the median umbilical ligament , medial umbilical ligaments , and bladder dome , was excised .
if oncologically indicated , an en bloc excision and pelvic lymphadenectomy could be performed completely by robot - assisted surgery .
the bladder was closed in two layers in a watertight running fashion with 2 - 0 vicryl .
the mobilization of the bladder and the suturing were done more efficiently by use of the robotic instruments , lowering the suturing time to less than 30 minutes .
tareen et al reported their initial experiences with robot - assisted laparoscopic partial cystectomy and diverticulectomy , and their mean operative duration was 190 minutes and the estimated blood loss was 35 ml ; these results were similar to ours .
with regard to pathologic results , urachal cyst , patent urachus , and urachal cystadenoma were diagnosed in our cases .
patent urachus and urachal cyst can present with numerous signs such as drainage of fluid from the umbilicus , calculus formation in cysts , abdominal pain due to cystic hemorrhage , and peritonitis .
urachal cystadenoma is a rarely reported pathology that can cause a palpable mass and abdominal pain .
an aggressive clinical course can occur with the development of pseudomyxoma peritonei . in our study , adult patients over 40-years - old were included .
adult patients with urachal anomalies should undergo an abdominal ct scan because of the high risk of malignancy of up to 25% .
ashley et al reported the increased risk of malignancy of a cystic urachal mass with increasing age . in their study ,
although open partial cystectomy and laparoscopic partial cystectomy have been treatments of choice for many years , our perioperative results of rlpc were comparable with those of laparoscopic partial cystectomy for urachal adenocarcinoma .
the robot - assisted laparoscopic approach in partial cystectomy is an attractive surgical alternative because of its association with superior surgical management with 3-dimensional magnified visualization and 7 degrees of articulation , which leads to fine resection and delicate intracorporeal suturing for anastomosis of the bladder with minimal difficulty .
the disadvantages of a robotic system are its relatively high cost , lack of tactile feedback , additional operation time for the docking procedure , and additional port placement compared with conventional laparoscopic partial cystectomy . considering our initial experience with these 4 cases of rlpc , after sufficient experience
, the time for the docking procedure can be minimized , and the number of ports placed can be reduced to 4 or 5 ports by excluding the 5 mm assistant port and the third arm port . despite several disadvantages , the superior surgical management of the robotic system enables the surgeon to perform a delicate operation in a tight pelvic cavity .
a randomized controlled study comparing rlpc with conventional laparoscopic partial cystectomy or open partial cystectomy is not feasible because of the rarity of benign urachal diseases .
our initial clinical experience suggests that rlpc is a feasible and safe treatment modality for patients with benign urachal diseases .
 purposein this study , we report our initial experience with robot - assisted laparoscopic partial cystectomy ( rlpc ) in urachal diseases.materials and methodstwo men and two women with a mean age of 51.59.3 years underwent rlpc between june 2009 and december 2009 . in each case , a single surgeon using the da vinci - s robotic system ( intuitive surgical , sunnyvale , ca , usa ) used a transperitoneal approach with a 0 robotic camera . 
 after careful observation of the intravesical portion of the mass , the mass was excised by use of monopolar scissors circumferentially . 
 the bladder was closed in two layers with watertight running sutures made with 2 - 0 vicryl.resultsthe mean operative time was 198 minutes ( range , 130 - 260 minutes ) , the mean console time was 111 minutes ( range , 70 - 150 minutes ) , and the mean estimated blood loss was 155 ml . 
 the urethral catheter was removed on postoperative day 7 after a normal cystogram , and the surgical drain was removed on postoperative day 2.5 ( range , 2 - 3 days ) . 
 the mean hospital stay was 6 days ( range , 4 - 7 days ) . 
 there were no major complications . 
 the pathology report revealed that one patient had a urachal cystadenoma , two patients had a urachal cyst , and one patient had a patent urachus.conclusionsour initial experience with rlpc for benign urachal disease is that it is a safe and feasible treatment modality . 
 however , more cases are required to confirm the efficacy of rlpc . 
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
CONCLUSIONS