Development and evaluation of vesicourethral anastomosis bench-top model for measurement of traction force on urethra in robotic surgery.

PURPOSE: In vesicourethral anastomosis (VUA), which is part of robot-assisted radical prostatectomy, surgeons must proceed carefully to avoid urethral damage. We developed and evaluated a VUA bench-top model that can measure the traction force on the urethra during robotic surgery. MATERIALS AND METHODS: The VUA model included the urethra, bladder, pelvic bones, and a small force sensor that was capable of measuring the traction force on the urethra. Eight skilled and eight novice urologists performed a VUA task in robotic surgery. The skilled surgeons assessed the model's realism and usefulness as a training tool using a 5-point Likert scale. The evaluation items [task time, maximum force, force volume, and length of time that specific excessive forces were applied to the urethra (2, 3, 4, and ≥ 5 N)] were compared between the skilled and novice surgeons using the Mann-Whitney U test. Measurements were conducted in four directions with respect to the maximum force on the urethra: 11-1, 2-4, 5-7, and 8-10 o'clock. RESULTS: The quality of the model was scored 3.7 to 4.9 points for all 16 items in 4 domains except for "Usefulness compared with animal models." There were differences in the task time and almost all force parameters between the skilled and novice surgeons. CONCLUSION: We developed a relatively high-quality VUA bench-top model that measures traction force on the urethra, and we have revealed differences in the forces of action on the urethra in two groups of surgeons with different skill levels.

Trifecta outcomes of robotic partial nephrectomy in obese patients: A comparison of body mass index <25, 25 to <30, and ≥30.

OBJECTIVE: We analyzed robotic partial nephrectomy (RPN) outcomes in obese patients based on body mass index (BMI) and trifecta achievement. METHODS: We retrospectively reviewed 296 patients who underwent RPN at Kansai Medical University Hospital between 2014 and 2022. The preoperative clinical data and perioperative outcomes were evaluated. Trifecta achievement (negative surgical margin, no major complications, and no acute kidney injury on postoperative day three) and its relationship to three BMI groups (<25, 25 to <30, and ≥30) were the primary outcome. The correlation between factors in achieving trifecta and BMI was evaluated. Univariate and multivariate analyses assessed variables for achieving the trifecta with logistic regression analysis. C-statistics quantitatively evaluated the prediction accuracy. RESULTS: Among 296 patients, 264 (89.2%) achieved trifecta (BMI categories were <25 [89.9%], 25 to <30 [89.4%], and ≥30 [82.6%]). There was no significant BMI-related difference (p = 0.566). Intraoperative blood loss increased with the BMI (p = 0.034). Multivariate analyses showed preoperative aspects and dimensions used for anatomic (PADUA) score independently predicted trifecta failure (odds ratio 1.71; 95% confidence interval 1.32-2.20; p < 0.001). The C-statistics of the PADUA score increased with increasing BMI. CONCLUSIONS: Higher BMI patients had more intraoperative blood loss during RPN. However, RPN remains safe and has acceptable quality and functional outcomes. Since patients with high PADUA scores combined with a high BMI may be at risk of trifecta failure, this should be explained before RPN.

Analysis of the posture pattern during robotic simulator tasks using an optical motion capture system.

BACKGROUND: Surgeons are sometimes forced to maintain uncomfortable joint positions during robotic surgery despite the high degree of instrument maneuverability. This study aimed to use an optical motion capture system to analyze the differences in posture patterns during robotic simulator tasks between surgeons at two skill levels. METHODS: Ten experienced and ten novice surgeons performed two tasks in a da Vinci Skills Simulator: Suture Sponge 1 (SP) and Tubes (TU). The participants' upper body motion during each task was captured, including the joint angles (axilla, elbow, and wrist), the percentage of time when the wrist height was lower than the elbow height (PTW), and the height of the elbow and wrist relative to the armrest. RESULTS: The novice group showed significantly more excess extension in both elbow angles and extension (>50°) in both wrist angles than did the experienced group. The novice group had significantly lower PTW than the experienced group on the right side in both tasks (both p < 0.001), and on the left side in SP (p < 0.001). Compared with the experienced group, the novice group had a significantly higher elbow relative to the armrest on the right side (SP, TU: p < 0.05), and a significantly lower wrist relative to the armrest on the right side (SP, TU: p < 0.05). CONCLUSIONS: An optical motion capture system can detect the differences in posture patterns in the positional relationship between the elbow and wrist and the joint angles of the upper limb between two groups of surgeons at different skill levels during robotic simulator tasks.

[Late Relapse of Testicular Cancer at the Pelvis with Elevated AFP Levels : A Case Report].

We report a patient with seminoma which recurred as late relapse at the pelvis with elevated alphafetoprotein (AFP) levels. A 40-year-old man presented with a left testicular tumor and subsequently underwent high orchiectomy in 2006. Pathological findings showed that the tumor was a seminoma with invasion into the tunica albuginea (pT2N0M0). Seven years after surgery, computed tomography showed a 12×8.7 mm, well-circumscribed, pelvic cystic tumor, and AFP and human chorionic gonadotropin levels were elevated. He was clinically diagnosed with recurrent testicular cancer. Despite the fact that the patient had four courses of bleomycin, etoposide, and cisplatin (BEP), the tumor enlarged and AFP levels were still elevated. Therefore, we performed open excision of the pelvic tumor. Judging from the pathological report, we made the final diagnosis of mature cystic teratoma. The patient was free of recurrence or metastasis within 48 months of follow-up.

Comparison of live donor pre-transplant and recipient post-transplant renal volumes.

BACKGROUND: Live donor pre-transplant and recipient post-transplant kidney volumes based on three-dimensional computed tomography (3DCT) have been related to post-transplant renal function. We examined this association and the effect of sex/size differences between donor and recipient on kidney growth rate. METHODS: We retrospectively reviewed 30 live donors who underwent pre-transplant and post-transplant 3DCT. We determined donor (Dvol) and recipient renal volumes (Rvol) based on 3DCT and calculated changes in graft volume after transplantation (Vol-ratio). We also divided Dvol by recipient body weight (Dvol/RWgt) and compared the correlations between Vol-ratio and Dvol/RWgt and post-transplant renal function after one yr. We determined the rates of change in kidney volume and renal function according to the sexes of the donor and recipient. RESULTS: The mean Dvol and Rvol were 141.7 and 178.4 mL, respectively. The mean Vol-ratio was 127.3%. Dvol/RWgt showed a significant linear correlation with remaining renal function after one yr (r = 0.6745, p < 0.0001). The combination of female donor and male recipient resulted in the fastest increase in kidney volume (p < 0.001) and highest level of proteinuria (p < 0.001). CONCLUSIONS: Pre-transplant and post-transplant kidney volumes are correlated with post-transplant graft function, and graft growth is affected by the relative sexes of the recipient and donor.

Comparison of diameter-axial-polar nephrometry score and RENAL nephrometry score for surgical outcomes following laparoscopic partial nephrectomy.

OBJECTIVES: To compare diameter-axial-polar nephrometry score with RENAL nephrometry score for surgical outcomes after laparoscopic partial nephrectomy. METHODS: We retrospectively reviewed data from 134 patients who underwent laparoscopic partial nephrectomy, using diameter-axial-polar and RENAL scores. We analyzed data for warm ischemic time and estimated blood loss intraoperatively, and percentage change in estimated glomerular filtration rate 6 months and 1 year postoperatively. Both scores were classified as low-, middle- and high-risk, and were used to compare the three analyzed parameters. RESULTS: The median tumor size was 2.3 cm (range 1.0-5.4 cm); warm ischemic time was 25.4 min (range 6.5-57 min); and at 6 months and 1 year, percentage change in estimated glomerular filtration rate was 93% (range 51.7-133.3%) and 91% (range 49.4-137.6%), respectively. There were no significant differences in warm ischemic time and estimated blood loss for RENAL between risk groups (P = 0.38 and 0.09, respectively), but significant differences between groups for diameter-axial-polar score (P = 0.02 and 0.01, respectively). There were no significant differences in either score between groups for percentage change in estimated glomerular filtration rate at 6 months and 1 year. A total of 27 high-risk cases with a diameter-axial-polar score of seven points underwent laparoscopic partial nephrectomy safely; all three cases with a diameter-axial-polar score of eight points were converted to open partial nephrectomy. CONCLUSIONS: Diameter-axial-polar score seems to estimate the complexity of tumor characteristics in patients undergoing laparoscopic partial nephrectomy better than RENAL score. It has a better correlation with warm ischemic time and estimated blood loss.

Laparoscopic upper-pole heminephrectomy for duplicated renal collecting system with superselective artery clamping using virtual partial nephrectomy analysis of Synapse Vincent: A case report.

A 22-year-old woman was diagnosed with a duplicated renal collecting system with hydronephrosis and parenchymal loss in the upper pole of the left kidney. She underwent laparoscopic left upper-pole nephrectomy. Although a complex hilar vascular anatomy was identified during the operation, preoperative three-dimensional computed tomographic reconstruction using a three-dimensional image analysis device (Synapse Vincent; Fuji Medical Systems, Tokyo, Japan) greatly helped to accurately identify the anatomical renal hilum. For further detail, virtual partial nephrectomy analysis using a Voronoi decomposition was used to visualize the area supplied by a selected arterial branch including the atrophic cleavage line. We controlled the bleeding with selective clamping and safely carried out upper-pole heminephrectomy according to the preoperative plan.

[Transvesical Removal of Seminal Vesicle Cystadenoma].

Primary tumors of the seminal vesicles are extremely rare. There have been 25 reports of this tumor from overseas and most cases are cystadenoma. We report a case of seminal vesicle cystadenoma in a 70-year-old man who presented with lower abdominal pain and urinary frequency. A digital rectal examination detected a projecting and hard mass in the right side of the prostate. Magnetic resonance imaging (MRI) showed a 15 cm multiple cystic mass continuous with the right seminal vesicle. A transrectal needle biopsy revealed benign tissue. The tumor was resected using an open transvesical approach that enabled full exposure of the seminal vesicle without damaging the nerves and blood supply of the bladder. Pathology was consistent with a benign seminal vesicle cystadenoma. We describe the natural history, pathology,and surgical approach in this case.

[Cosmesis and Body Image after Laparo-Endoscopic Single Site Donor Nephrectomy].

Using a questionnaire, we objectively assessed the body image of donors who underwent conventional laparoscopic donor nephrectomy (L-DN) or laparoscopic single-site donor nephrectomy (LESS-DN). Subjects were 15 patients who underwent an L-DN and 15 who underwent an LESS-DN. The questionnaire consisted of the Body Image Questionnaire (BIQ), including a Body Image Scale (BIS) and Cosmetic Scale (CS), and a Photo-Series Questionnaire (PSQ). A higher score indicated a more favorable assessment, and patient scores were compared. Subjects were also asked which procedure they preferred if they had to undergo donor nephrectomy again. Pain was assessed by comparing the number of times an analgesic was administered during hospitalization. The average BIS score was 18.7 points (out of 20) for patients who underwent an L-DN and 19.5 points for patients who underwent an LESS-DN ; those who underwent an LESS-DN had a significantly higher score (p=0.03). Patients who underwent an L-DN had a median CS score of 17.5 points (out of 24) while patients who underwent an LESS-DN had a median CS score of 19.1 points ; those who underwent an LESS-DN had a higher score, but the difference in average CS scores was not significant (p=0.123). The average PSQ score was 7.1 points for patients who underwent an L-DN and 8.8 points for patients who underwent an LESS-DN ; the higher score for LESS-patients was statistically significant (p=0.01). Patients who underwent an L-DN were administered an analgesic a median of 4 times during hospitalization (range : 3-10 times) while patients who underwent an LESS-DN were administered an analgesic a median of 2 times (range : 0-4 times), which was significantly less (p=0.01). Patients who underwent LESS-DN had a better body image and better cosmetic appearance than those who underwent LDN, thus indicating the usefulness of LESS-DN. However, a more prospective larger study needs to be performed.

Analysis of Gripping Force on a Master Controller During Simulated Robotic Surgery.

Background: Although robotic surgery can improve ergonomics, strain in the hand and wrist is commonly reported. We evaluated gripping force differences between novice and expert surgeons while performing a da Vinci surgical simulator task. Methods: By attaching two force sensors to both master controllers, the average gripping force (AF) and maximum gripping force (MF) were evaluated. Participants (11 experts and 10 novices) performed the Suture sponge 1 task. Results: Almost all AF and MF in the dominant hand of experts were significantly smaller than those of novices. Mean gripping force with the dominant hand was correlated with the number of missed targets (r = 0.63, p = 0.002). Conclusions: Experts applied softer gripping force with the dominant hand than novices. Increased AF in the dominant hand was associated with more missed targets. These results may support learners to relax while performing robotic surgical procedures.

Upper body position analysis of different experience level surgeons during laparoscopic suturing maneuvers using optical motion capture.

BACKGROUND: This study aimed to analyze the posture patterns of surgeons with two different skill levels during laparoscopic surgery using an optical motion capture system. METHODS: Twenty participants were divided into novice and expert groups. Their upper body motions during suturing tasks were captured, including average angle and angle variability (shoulder, elbow, wrist), joint fixation, head movement, and thoracolumbar flexion angle. RESULTS: Our analysis showed that (1) the arms of the expert surgeons were more loosely held at their sides by about 7°; (2) their elbows were more bent by about 10°; (3) they had a greater change in shoulder angle by about 1.4 times and a more fluid posture; (4) their heads were more stable, particularly in the longitudinal and vertical axes; and (5) their thoracolumbar flexion angle was smaller by about 10°. CONCLUSIONS: The posture patterns of different technical level surgeons during laparoscopic suturing maneuvers revealed differences in limb positions. These results may provide new insights into the efficient acquisition of technical skills and reduced physical stress during laparoscopic surgery.

Analysis of the tractive force pattern on a knot by force measurement during laparoscopic knot tying.

BACKGROUND: Quantifying surgical skills assists novice surgeons when learning operative techniques. We measured the interaction force at a ligation point and clarified the features of the force pattern among surgeons with different skill levels during laparoscopic knot tying. METHODS: Forty-four surgeons were divided into three groups based on experience: 13 novice (0-5 years), 16 intermediate (6-15 years), and 15 expert (16-30 years). To assess the tractive force direction and volume during knot tying, we used a sensor that measures six force-torque values (x-axis: Fx, y-axis: Fy, z-axis: Fz, and xy-axis: Fxy) attached to a slit Penrose drain. All participants completed one double knot and five single knot sequences. We recorded completion time, force volume (FV), maximum force (MF), time over 1.5 N, duration of non-zero force, and percentage time when vertical force exceeded horizontal force (PTz). RESULTS: There was a significant difference between groups for completion time (p = 0.007); FV (total: p = 0.002; Fx: p = 0.004, Fy: p = 0.007, Fxy: p = 0.004, Fz: p < 0.001, Fxy/Fz: p = 0.003), MF (total: p = 0.004; Fx: p = 0.015, Fy: p = 0.035, Fxy: p = 0.009, Fz: p = 0.001, Fxy/Fz: p = 0.041); time over 1.5 N (p = 0.002); duration of non-zero force (p = 0.029); and PTz (p < 0.001). PTz showed the only significant difference comparing intermediates with experts (intermediates: 13.7 ± 9.0, experts: 4.9 ± 3.2; p < 0.001). CONCLUSIONS: We clarified the characteristics of the force pattern at the ligation point during suturing by surgeons with three levels of experience using a force measurement system. We revealed that both force volume and force direction differed depending on surgeons' skill level during knot tying.