Cumulative summation graphs are a useful tool for monitoring positive surgical margin rates in robot-assisted radical prostatectomy

Learning curve of multiple surgeons for robot-assisted radical prostatectomy using the cumulative sum method: a retrospective single-institution study

Prostate cancer (PC) is common among men and has become a significant societal issue. Localized PC has a good prognosis with appropriate treatment. Prostatectomy, particularly robot-assisted radical prostatectomy (RARP), has become a common treatment since the da Vinci prostatectomy was approved by the FDA in 2001. The current study aimed to assess the learning curve for RARP, focusing on anastomosis time, using the cumulative sum (CUSUM) method. Data were collected from Nagoya City University Hospital between May 2011 and December 2018 and included 469 surgeries performed by experienced surgeons. Our findings indicated that, on average, 11 patients were required to complete the initial phase and 24 patients were required to complete the consolidation phase of anastomosis. Additionally, for complete resection of pT2c cases, 16 cases were required for the initial phase and 27 cases were required for the consolidation phase. The CUSUM method proved useful for visualizing trends in surgical proficiency, although the study noted potential confounding biases and limitations in evaluating surgical proficiency based solely on surgical time or positive surgical margins.

A Systematic Review on the Impact of Quality Assurance Programs on Outcomes after Radical Prostatectomy

BACKGROUND AND OBJECTIVE

The implementation of quality assurance programs (QAPs) within urological practice has gained prominence; yet, their impact on outcomes after radical prostatectomy (RP) remains uncertain. This paper aims to systematically review the current literature regarding the implementation of QAPs and their impact on outcomes after robot-assisted RP, laparoscopic RP, and open prostatectomy, collectively referred to as RP.

METHODS

A systematic Embase, Medline (OvidSP), and Scopus search was conducted, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) process, on January 12, 2024. Studies were identified and included if these covered implementation of QAPs and their impact on outcomes after RP. QAPs were defined as any intervention seeking quality improvement through critically reviewing, analyzing, and discussing outcomes. Included studies were assessed critically using the Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) tool, with results summarized narratively.

KEY FINDINGS AND LIMITATIONS

Ten included studies revealed two methodological strategies: periodic performance feedback and surgical video assessments. Despite conceptual variability, QAPs improved outcomes consistently (ie, surgical margins, urine continence, erectile function, and hospital readmissions). Of the two strategies, video assessments better identified suboptimal surgical practice and technical errors. Although the extent of quality improvements did not appear to correlate with the frequency of QAPs, there was an apparent correlation with whether or not outcomes were evaluated collectively.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Current findings suggest that QAPs have a positive impact on outcomes after RP. Caution in interpretation due to limited data is advised. More extensive research is required to explore how conceptual differences impact the extent of quality improvements.

PATIENT SUMMARY

In this paper, we review the available scientific literature regarding the implementation of quality assurance programs and their impact on outcomes after radical prostatectomy. The included studies offered substantial support for the implementation of quality assurance programs as an incentive to improve the quality of care continuously.

A cumulative sum (CUSUM) analysis studying operative times and complications for a surgeon transitioning from laparoscopic to robot-assisted pediatric pyeloplasty: Defining proficiency and competency

INTRODUCTION

The transition from laparoscopic to robot-assisted procedures leads to potential increase in operative times and health care costs. Cumulative sum (CUSUM) analysis can objectively study the learning curve to detect significant changes in operative timing and monitor complication rates.

OBJECTIVE

The objective of this study is to investigate the total and step-specific times for pediatric robot-assisted pyeloplasty (RAP) to investigate the learning curve of a single surgeon transitioning from laparoscopic to RAP.

STUDY DESIGN

This prospective cohort study included 50 consecutive RAP procedures performed since the inception of our robotic program from June 2013 to January 2019. The CUSUM of RAP total operative time (OT) was calculated to determine the breakpoints between learning phases using piecewise linear regression. Cumulative-observed-minus-expected failure chart with 80% and 95% reassurance boundary lines was constructed using 5% acceptable and 10% unacceptable complication rates. Step-specific operative times were prospectively recorded by an independent observer for port placement, dissection and hitch stitch placement, pelvis dismemberment and spatulation, suturing and port removal.

RESULTS

Piecewise linear regression for OT identified breakpoints at case 13 and 29 suggesting transition at these points between Learning to Proficiency, and Proficiency to Competency. The overall mean OT was 142.2 ± 46.0 min. There was a significant difference in the mean OT between Learning (203.9 ± 35.3 min, the initial 13 cases), Proficiency (159.2 ± 18.6 min, the middle 16 cases), and Competency (126.6 ± 19.7 min, the last 21 cases) phases (p < 0.001). The complication rate for RAP stabilized around the acceptable level of 5% up to case 41 before finalizing at 8% overall. The step-specific analysis suggested that suturing entered the Competency phase at case 27, with a 50% decrease in suturing time from Learning to Proficiency and Competency.

DISCUSSION

Our study suggests that by case 30 a surgeon transitioning to RAP can achieve a significant decrease in OT. Complication rates remained within acceptable limits throughout, indicating that RAP can be safely adopted, even in low volume RAP centres. Suturing competency seems to be a significant advantage of the robotic platform as suggested by early significant decrease in suturing times noted between the Learning and Proficiency phases.

CONCLUSION

Future studies can confirm these findings and establish reference operative times to aid surgeons and trainees transitioning from laparoscopic pyeloplasty to RAP. Moreover, total OT decreases significantly and relatively soon after transition to RAP.

A multi-surgeon learning curve analysis of overall and site-specific positive surgical margins after RARP and implications for training

Robot-assisted radical prostatectomy (RARP) is the most adopted treatment for localized prostate cancer. The aim of this study was to explore the learning curves (LC) for overall and site-specific positive surgical margins (PSM) occurrence after RARP of multiple surgeons within a step-structured mentor-initiated training program. The study included consecutive patients undergoing RARP between January 2013 and March 2020, by three surgeons: a mentor and his two trainees. Prospectively collected patients' data were retrospectively analyzed. The cumulative summation (CUSUM) method was used to generate the LCs, with turning points indicating the number of cases to reach proficiency levels. Furthermore, the association between PSM and surgical experience was evaluated, adjusting for case mix. A total of 761 consecutive patients were included, 370 treated by the Mentor surgeon, 247 and 144 treated, respectively, by the two Trainees. Mentor and Trainees had similar PSM rates (31.6% vs 28.0% vs 31.3%, p = 0.6). CUSUM charts showed different LC shapes for different PSM locations (postero-lateral, bladder neck, apex, and multifocal/> 3 mm). Surgical experience was significantly associated with overall, postero-lateral, and multifocal/> 3 mm PSMs, in the Mentor series only. Trainees reached their turning points after far fewer cases then the Mentor, both for overall (12 and 31 vs 153), postero-lateral (24 and 30 vs 120), and multifocal/> 3 mm PSMs (9 and 31 vs 153). The achievement of stable SM proficiency takes involved different LCs depending on the prostatic location being considered. Monitoring site-specific LC can indicate the surgical steps for which there may be still room for further technical refinements, even when an apparent proficiency status seems achieved.

Cumulative sum analysis of the learning curve of ptosis surgery: External levator advancement versus Müller's muscle-conjunctival resection

Purpose

Even though it is stated that external levator advancement (ELA) has a much longer learning curve than Müller muscle-conjunctival resection (MMCR) in the treatment of aponeurotic ptosis, there is no study in the literature regarding the learning curves of these two surgical techniques. We aimed to objectively determine the length of the learning curves of ELA and MMCR using cumulative sum (CUSUM) analysis.

Methods

The first 30 unilateral ELA and the first 30 unilateral MMCR consecutively performed by a single surgeon were retrospectively reviewed. The CUSUM method was used to analyze the learning curves of ELA and MMCR based on operation times of consecutive surgeries and the clinical outcomes were compared.

Results

CUSUM analyses revealed that the operation time stabilized after around 11 ELA surgeries and 12 MMCR surgeries and R² value for ELA and MMCR were 0.93 and 0.91, respectively. There was no significant difference in these stratified analyses. Mean operation time was 45.7 minutes in the ELA group and 34.1 minutes in the MMCR group (p = 0.002). Total number of intraoperative complications was 37 in the ELA group and 16 in the MMCR group (p = 0.015). Symmetry success rate was significantly higher (p < 0.0001) and reoperation rate was significantly lower in the MMCR group (p = 0.045).

Conclusions

Even though ELA is more challenging than MMCR, comparable learning curves indicate that surgeons in training need to be encouraged to perform both techniques. The challenges and obstacles that the surgeons in training face in these two techniques need to be analyzed in detail.

Comparison Study of Learning Curve Using Cumulative Sum Analysis Between Holmium Laser Enucleation of the Prostate and Transurethral Resection of the Prostate: Is Holmium Laser Enucleation of the Prostate a Difficult Procedure for Beginner Urologists?

Objectives: Although there is no comparison study about the learning curves for holmium laser enucleation and other surgical modalities to treat benign prostatic hyperplasia (BPH), beginner urologists are hesitant to perform holmium laser enucleation because of its steep learning curve. Therefore, we investigated the degree of surgical difficulty of holmium laser enucleation by comparing its learning curve with that of transurethral resection. Patients and Methods: Two beginner urologists performed surgery for BPH: H.J.Y. performed holmium laser enucleation and K.H.K. performed transurethral resection. Of 141 patients, 72 were enrolled in the holmium laser enucleation group and 69 in the transurethral prostate resection group. After retrospectively reviewing medical records, we performed a cumulative sum analysis of resection speed (RS) and resected ratio (RR) to compare the learning curves of holmium laser enucleation and transurethral resection. Results: Both surgeons achieved RS competency with a speed <0.13 g/min. The surgeon who performed holmium laser enucleation achieved RR competency with a ratio <0.40, whereas the surgeon who performed transurethral resection achieved competency with a ratio <0.35. To achieve RS competency of 0.13 g/mL, the holmium laser enucleation and transurethral resection groups required 12 and 23 cases, respectively. To achieve RR competency of 0.35, the holmium laser enucleation and transurethral resection groups required 12 and 5 cases, respectively. Conclusions: Holmium laser enucleation is not a difficult procedure compared with transurethral resection in beginner urologists. Therefore, it is unnecessary to avoid holmium laser enucleation because the concerns that it may be difficult are unfounded.

Medico-economic impact of robot-assisted lung segmentectomy: what is the cost of the learning curve?

OBJECTIVES

The objective of this study was to assess the learning curve (LC) of robot-assisted lung segmentectomy and to evaluate hospital-related costs.

METHODS

We conducted a retrospective study of Robot-assisted thoracic surgery (RATS) segmentectomies performed by 1 surgeon during 5 years. Perioperative and medical device data were collected. The LC, based on operating time, was assessed by Cumulative SUM analysis and an exponential model. Cost of care was estimated using the French National Cost Study method.

RESULTS

One hundred and two RATS segmentectomies were included. The LC was completed at ∼30 procedures according to both models without significant difference in patients' characteristics before or after the LC. Mean operative time decreased from 136 min [95% confidence intervals (CI) 124-149] for the first 30 procedures to 97 min (95% CI 88-107) for the last 30 procedures. Mean length of stay decreased non-significantly (P = 0.10 for linear trend) from 8.1 days (95% CI 6.1-11.0) to 6.2 days (95% CI 4.9-7.9). The overall costs for the last 30 procedures as compared with the first 30 did not significantly decrease in the primary economic analysis but significantly decreased (P = 0.02) by €1271 (95% CI -2688 to +108, P = 0.02 for linear trend) after exclusion of 1 outlier (hospitalization-related costs > €10 000). After exclusion of this outlier, costs related to EndoWrist® instruments significantly decreased by €-135 (95% CI -220 to -35, P = 0.004), whereas costs related to clips decreased non-significantly (P = 0.28).

CONCLUSIONS

The LC was completed at ∼30 procedures. Inexperienced surgeons may have higher procedure costs, related to consumable medical devices and operating time.

The Use of Cumulative Sum Analysis to Derive Institutional and Surgeon-Specific Learning Curves for Robot-Assisted Radical Prostatectomy

Purpose: The cumulative sum (CUSUM) approach has been adopted to evaluate surgical competence in various contexts. The CUSUM method comprises sequential monitoring of cumulative differences from a target level in performance quality over time, allowing the detection of deviations from the target. We use the CUSUM method in this study to derive both institutional and surgeon-specific learning curves for robot-assisted radical prostatectomy (RARP). Patients and Methods: We reviewed 540 patients diagnosed with localized prostate cancer (pathologic stage T2) who underwent RARP at our institution between September 2011 and December 2017. The CUSUM method was used to construct both institutional and individual-surgeon learning curves; the outcome was assessed based on whether a positive surgical margin (PSM) was present. The target PSM rate was 20%. Of seven surgeons performing robot-assisted resections for this period, four who performed ≥60 resections were assessed separately. Results: Of 540 patients, 74 (14%) had PSMs. The institutional CUSUM chart exhibited a downward trend for the first 54 cases and an upward trend thereafter. The CUSUM chart for the earliest adopter was similar to that for the institution; that is, learning was complete at 45 cases. Two adopters did not undergo a learning curve as they consistently performed well. The last adopter required 10 cases for initial learning. However, his CUSUM chart trend became negative at 46 cases and remained so afterward. Conclusions: CUSUM charts are useful for monitoring surgical quality. Long-term monitoring of the PSM rate of a surgeon who has become independent allows an attending surgeon to intervene if necessary; thus, long-term quality control is assured.

Use of cumulative summation (CUSUM) as a tool for early feedback and monitoring in robot-assisted radical prostatectomy outcomes and performance

INTRODUCTION

Today's surgical practice has evolved, with increasing emphasis on quality assurance. Many forms of quality-control monitoring have been suggested, but they are often impractical or difficult to implement. Cumulative summation (CUSUM) is a simple method to provide visual feedback before significant quality issues arise. We present our initial use and practical application of CUSUM in a surgical practice.

METHODS

A retrospective analysis was applied to a prospectively collected database of 577 sequential patients who have undergone robot-assisted radical prostatectomy from a single surgeon over a 10-year period. Outcome measures were analyzed with CUSUM, which included a composite complication score, continence rates, length of hospital stay, biochemical recurrence, and need for adjuvant radiation. If any outcomes were out of control, they would cross the CUSUM failure line.

RESULTS

CUSUM chart-plotting for incontinence demonstrated an initial upward slope followed by trending to a new safety limit. Additionally, outcomes in complications and biochemical recurrence did not reach the established safety boundaries. Length of stay and radiation outcomes did initially cross the safety line, but were improved over time.

CONCLUSIONS

The use of CUSUM in clinical practice can fulfill the need for quality assurance. CUSUM plotting in our practice reflected the initial learning curve, followed by ongoing maintenance and improvement in performance. These changes were consistent with the implementation of changes in surgical techniques. Although this tool was used retrospectively, this strengthens our argument to implement the tool prospectively and assess real-time refinement of surgeon skill. We have demonstrated that CUSUM can be appropriately used to assure quality control in a surgical practice.

The comparison of surgical outcomes and learning curves of radical hysterectomy by laparoscopy and robotic system for cervical cancer: an experience of a single surgeon

Objective

The aim of this study was to compare and determine the feasibility, surgical outcomes, learning curves of robotic radical hysterectomy with lymph node dissection (RRHND) to conventional laparoscopic radical hysterectomy with lymph node dissection (LRHND) performed by a single surgeon, in patients with cervical cancer.

Methods

Between April 2009 and March 2013, 22 patients underwent LRHND and 19 patients underwent RRHND. Variables such as age, body mass index, International Federation of Gynecology and Obstetrics stage, histological results, number of dissected lymph nodes, operative time, estimated blood loss, days of hospitalization and complications were reviewed. Learning curves of operation time was obtained using cumulative sum (CUSUM) method.

Results

Both groups showed similar patient and tumor characteristics. In surgical outcome analysis, RRHND (51.8±10.4 minutes) showed longer preparing time than LRHND (42.5±14.1 minutes). In the LRHND group, 8 patients experienced postoperative complications (5 void difficulty, 1 postoperative bleeding, 1 right basal ganglia infarction, 1 fever). On the other hand, in the RRHND group, 4 patients experienced a postoperative complication (2 bleeding, 1 peritonitis, 1 dehiscence of trocar site). Using CUSUM method, the learning curves were obtained by plotting the cumulative sequential differences between each data point and the average operation time, and showed two distinct phases in both type of operations.

Conclusion

RRHND would be appropriate surgical approach in patients with cervical cancer with favorable outcome of less voiding difficulty. A minimum of 13 cases of robotic radical hysterectomies are required to achieve surgical improvement in the treatment of cervical cancer.

Evaluation of the learning curve for transcatheter aortic valve implantation via the transfemoral approach

BACKGROUND

The aim of this study was to evaluate the learning curve in performing transfemoral TAVI (TF-TAVI).

METHODS

Between October 2006 and October 2013, 312 consecutive TF-TAVI cases performed by 6 interventional cardiologists, using the Edwards Sapien valve and 104 using the CoreValve, were included in the present analysis. Cumulative sum (CUSUM) failure analysis of combined 30-day safety endpoint was used to evaluate learning curves.

RESULTS

The CUSUM analysis revealed a learning curve regarding the occurrence of 30-day adverse events with an improvement after the initial 86 cases using the Edwards valve and 40 cases using the CoreValve. We divided the Edwards valve cases into two groups (early experience: Cases 1 to 86; late experience: Cases 87 to 312). The rate of 30-day mortality and 1-year mortality significantly decreased in the late experience group (17% to 7%, p=0.019; 34% to 21%, p=0.035, respectively). We divided the CoreValve cases into two groups (early experience: Cases 1 to 40; late experience: Cases 41 to 104). The rate of 30-day mortality and 1-year mortality significantly decreased in the late experience group (20% to 6%, p=0.033; 38% to 15%, p=0.040, respectively). The groups including both valves were also analyzed after propensity-matching (early [n=52] vs late [n=52]). This model also showed that 30-day and 1-year mortality rates were significantly lower in the late experience group (13% to 1%, p=0.028; 34% to 20%, p=0.042, respectively).

CONCLUSIONS

An appropriate level of experience is needed to reduce the complication rate and mortality in TF-TAVI.

Learning curve evaluation using cumulative summation analysis-a clinical example of pediatric robot-assisted laparoscopic pyeloplasty

BACKGROUND

The cumulative summation (CUSUM) method for learning curve analysis remains under-utilized in the surgical literature in general, and is described in only a small number of publications within the field of pediatric surgery. This study introduces the CUSUM analysis technique and applies it to evaluate the learning curve for pediatric robot-assisted laparoscopic pyeloplasty (RP).

METHODS

Clinical data were prospectively recorded for consecutive pediatric RP cases performed by a single-surgeon. CUSUM charts and tests were generated for set-up time, docking time, console time, operating time, total operating room time, and postoperative complications. Conversions and avoidable operating room delay were separately evaluated with respect to case experience. Comparisons between case experience and time-based outcomes were assessed using the Student's t-test and ANOVA for bi-phasic and multi-phasic learning curves respectively. Comparison between case experience and complication frequency was assessed using the Kruskal-Wallis test.

RESULTS

A total of 90 RP cases were evaluated. The learning curve transitioned beyond the learning phase at cases 10, 15, 42, 57, and 58 for set-up time, docking time, console time, operating time, and total operating room time respectively. All comparisons of mean operating times between the learning phase and subsequent phases were statistically significant (P=<0.001-0.01). No significant difference was observed between case experience and frequency of post-operative complications (P=0.125), although the CUSUM chart demonstrated a directional change in slope for the last 12 cases in which there were high proportions of re-do cases and patients <6 months of age.

CONCLUSIONS

The CUSUM method has a valuable role for learning curve evaluation and outcome quality monitoring. In applying this statistical technique to the largest reported single surgeon series of pediatric RP, we demonstrate numerous distinctly shaped learning curves and well-defined learning phase transition points.

Systematic methods for measuring outcomes: How they may be used to improve outcomes after Radical cystectomy

In the era of managed healthcare, the measuring and reporting of surgical outcomes is a universal mandate. The outcomes should be monitored and reported in a timely manner. Methods for measuring surgical outcomes should be continuous, free of bias and accommodate variations in patient factors. The traditional methods of surgical audits are periodic, resource-intensive and have a potential for bias. These audits are typically annual and therefore there is a long time lag before any effective remedial action could be taken. To reduce this delay the manufacturing industry has long used statistical control-chart monitoring systems, as they offer continuous monitoring and are better suited to monitoring outcomes systematically and promptly. The healthcare industry is now embracing such systematic methods. Radical cystectomy (RC) is one of the most complex surgical procedures. Systematic methods for measuring outcomes after RC can identify areas of improvements on an ongoing basis, which can be used to initiate timely corrective measures. We review the available methods to improve the outcomes. Cumulative summation charts have the potential to be a robust method which can prompt early warnings and thus initiate an analysis of root causes. This early-warning system might help to resolve the issue promptly with no need to wait for the report of annual audits. This system can also be helpful for monitoring learning curves for individuals, both in training or when learning a new technology.

Cumulative summation (CUSUM) charts in the monitoring of hypospadias outcomes: a tool for quality improvement initiative

OBJECTIVE

Cumulative summation (CUSUM) charting is a statistical tool that allows an individual surgeon or surgical department to monitor any binary outcome and rapidly detect when complications are outside the acceptable limits. We applied CUSUM statistical analysis to hypospadias repair to utilize the results in our own quality Improvement process.

MATERIALS AND METHODS

An institutional review board-approved retrospective review of all patients who underwent hypospadias repair by a single fellowship trained pediatric urologist at a single institution between September 2004 to July 2009 was performed. To graphically represent the complication rates and to assess for unacceptable rates, the use of CUSUM control charting was employed.

RESULTS

In our retrospective review, there were a total of 184 patients who underwent a total of 203 surgeries. Using CUSUM analysis, our incidence of major complications was within acceptable limits until approximately the first 150 operations had been performed, at which time the complication rate fell below the lower limit, indicating performance exceeded expectations.

CONCLUSION

CUSUM statistical charting was successfully applied to the retrospective monitoring of hypospadias outcomes at our institution. This is the first known publication in which CUSUM charts were used to evaluate complications of hypospadias repair.

Robotic sacrocolpopexy performance and cumulative summation analysis

OBJECTIVES

This study aimed to apply Cumulative Summation (CUSUM) analysis as a tool to monitor robotic sacrocolpopexy (RSCP) proficiency over time.

METHODS

A retrospective analysis of all women who underwent RSCP between September of 2008 and December of 2011 at the University of North Carolina at Chapel Hill. The performance for 2 attending surgeons was analyzed sequentially over time. Intraoperative complications such as genitourinary or gastrointestinal tract injury, conversion to laparotomy, pulmonary embolus, hemorrhage, and blood transfusion, were identified by International Classification of Diseases, Ninth Revision and Current Procedural Terminology codes. A successful outcome was defined as no intraoperative complications. The target value of success was set at less than 10% complications. CUSUM analysis was then sequentially applied to all RSCP cases for 2 attending surgeons.

RESULTS

Over 27 months, 169 RSCPs were performed. The first surgeon performed 107 RSCPs and the second surgeon performed 62 RSCPs with 8 (7.4%) and 3 (4.9%) intraoperative complications, respectively. Total complications included 7 (4.1%) cystotomies, 2 (1.2%) vaginal lacerations, 1 (0.6%) blood transfusion, and 1 (0.6%) bowel perforation. A CUSUM graph was created for each surgeon.

CONCLUSIONS

CUSUM analysis was successfully applied to monitor RSCP proficiency. Such testing of individual successive procedural outcomes with CUSUM may offer an objective tool to aid in physician self-assessment.

Learning curve analysis of robot-assisted radical hysterectomy for cervical cancer: initial experience at a single institution

OBJECTIVE

The aim of this study was to evaluate the learning curve and perioperative outcomes of robot-assisted laparoscopic procedure for cervical cancer.

METHODS

A series of 65 cases of robot-assisted laparoscopic radical hysterectomies with bilateral pelvic lymph node dissection for early stage cervical cancer were included. Demographic data and various perioperative parameters including docking time, console time, and total operative time were reviewed from the prospectively collected database. Console time was set as a surrogate marker for surgical competency, in addition to surgical outcomes. The learning curve was evaluated using cumulative summation method.

RESULTS

The mean operative time was 190 minutes (range, 117 to 350 minutes). Two unique phases of the learning curve were derived using cumulative summation analysis; phase 1 (the initial learning curve of 28 cases), and phase 2 (the improvement phase of subsequent cases in which more challenging cases were managed). Docking and console times were significantly decreased after the first 28 cases compared with the latter cases (5 minutes vs. 4 minutes for docking time, 160 minutes vs. 134 minutes for console time; p<0.001 and p<0.001, respectively). There was a significant reduction in blood loss during operation (225 mL vs. 100 mL, p<0.001) and early postoperative complication rates (28% vs. 8.1%, p=0.003) in phase 2. No conversion to laparotomy occurred.

CONCLUSION

Improvement of surgical performance in robot-assisted surgery for cervical cancer can be achieved after 28 cases. The two phases identified by cumulative summation analysis showed significant reduction in operative time, blood loss, and complication rates in the latter phase of learning curve.

Comparison of oncological outcomes between retropubic radical prostatectomy and robot-assisted radical prostatectomy: an analysis stratified by surgical experience

OBJECTIVES

To compare oncological outcomes of a consecutive retropubic radical prostatectomy (RRP) and robot-assisted radical prostatectomy (RARP) series performed by a single surgeon who had performed >750 prior RRPs and was starting to perform RARPs.

MATERIALS AND METHODS

Prospectively collected longitudinal data of 277 RRP and 730 RARP cases over a 5-year period were retrospectively analyzed. The RARP series were divided into 3 subgroups (1st, <250 cases; 2nd, 250-500; and 3rd, >500) according to the surgical period. The positive surgical margin (PSM) and biochemical recurrence-free survival (BCRFS) rates were compared at each pathological stage.

RESULTS

The pT2 PSM rates showed no significant difference between the RRP (7.8%) and RARP series (1st, 9.5%; 2nd, 14.1%; and 3rd, 9.8%) throughout the study period (P = 0.689, 0.079, and 0.688, respectively). Although the pT3 PSM rates of the 1st (50.6%) and 2nd RARP series (50.0%) were higher than that of the RRP series (36.0%; P = 0.044 and P = 0.069, respectively), the 3rd RARP series had a comparable pT3 PSM rate (32.4%, P = 0.641). The 3-year BCRFS rates of the RRP and RARP series were similar at each pathological stage (pT2, 92.1 vs. 96.8%, P = 0.517; pT3, 60.0 vs. 67.3%, P = 0.265, respectively).

CONCLUSIONS

The pT2 PSM and short-term BCRFS rates were similar between RRP and RARP, and RARP showed comparable pT3 PSM rate with RRP after >500 cases of surgical experience. Our data suggest that an experienced robotic surgeon at a high-volume center may achieve comparable oncological outcomes with open prostatectomy even in locally advanced disease.

Safe introduction of robot-assisted radical prostatectomy after a training program in a high-volume robotic centre

INTRODUCTION

Localized prostate cancer is increasingly treated by robot-assisted radical prostatectomy (RARP). We evaluated the introduction of RARP following a training program at a high-volume robotic center.

MATERIALS AND METHODS

Before starting RARP, a young urologist followed a 6-month training program. The outcome of his first 50 RARPs was compared with the last 50 open radical prostatectomies (ORPs) performed by an experienced urologist at the same institution. Tumor characteristics were similar in both groups. Median follow-up was 12 (RARP) and 31 (ORP) months (p < 0.001).

RESULTS

RARP was associated with more nerve sparing (82 vs. ORP 46%, p < 0.001), longer operation time [median 205 (range 120-310) vs. ORP 180 (85-280) min, p = 0.001], lower decline of postoperative hemoglobin [RARP -2.1 (0.1-4.5) vs. ORP -4.0 (1.0-7.0) g/dl, p < 0.001] and shorter catheter stay [6 (5-47) vs. ORP 14 (9-43) days, p < 0.001]. Complication rates were similar. Overall and pT2-positive surgical margin rate was 8 vs. 24% (p = 0.054) and 0 vs. 11.8% (p = 0.114) for RARP vs. ORP, respectively. One-year urinary continence rate was 76.7 (RARP) and 75.8% (ORP, p = 0.833).

CONCLUSIONS

RARP was safely introduced after a training program in a high-volume robotic center, both surgically, oncologically and functionally.

Real-time outcome monitoring following oesophagectomy using cumulative sum techniques

AIM: To examine the feasibility of prospective, real-time outcome monitoring in a United Kingdom oesophago-gastric cancer surgery unit.

METHODS: The first 100 hybrid (laparoscopic abdominal phase, open thoracic phase) Ivor-Lewis oesophagectomies performed by a United Kingdom oesophago-gastric cancer surgery unit were assessed retrospectively using cumulative sum (CUSUM) techniques. The monitored outcome was 30-d post-operative mortality, with the accepted mortality risk defined as 5%. A variable life adjusted display (VLAD) was constructed by plotting a graph of cumulative mortality minus cumulative mortality risk on the y axis vs sequential case number on the x axis. This was modified to a zeroed VLAD by preventing the plot from crossing the y = 0 axis - essentially creating two plots, one examining trends where cumulative mortality was higher than mortality risk (i.e., worse than expected outcomes) where y > 0, and vice versa. Alert lines were set at y = ± 2. At any point where a plot breaches an alert line, it is felt that the 30-d post-operative mortality rate has deviated significantly from that expected and an internal review should be performed.

RESULTS: One hundred cases were assessed, with a mean age of 66.4 years, mean T stage of 2.1, and mean N stage of 0.48. Three cases were commenced using a laparoscopic technique and converted to open surgery due to technical factors. Median length of inpatient stay was 15 d. The crude 30 d mortality was 5% and the incidence of clinically significant anastomotic leak was 6%. The VLAD demonstrated a plot of cumulative mortality minus cumulative mortality risk (i.e., 5% per case) which remained in the range -1.4 to +0.5 excess mortalities. With the alert set at two greater or fewer than predicted mortalities, this method does not approach the point of triggering internal review. It is however arguable that a run of performance that is better than expected, causing the plot to be well below y = 0, would mask a subsequent run of poor performance by requiring a rise of greater than two excess mortalities to trigger the alert line. The zeroed VLAD removes this problem by preventing the plot that is examining above expected mortality from passing below y = 0, and vice versa. In this study period, no audit triggers were reached. It is therefore possible to independently assess runs of good, or poor performance and so target internal audit to the appropriate series of cases. It is important to note this technique allows targeted internal review, in response to both above and below average outcomes. This study has demonstrated the feasibility of prospective outcome monitoring using the above techniques, actual real-time implementation has the potential to pick up and reinforce good practices when performance is better than predicted, and provide an early warning system for when performance falls below that predicted. Further development is possible, including more patient specific risk adjustment using the oesophago-gastric surgery physiological and operative severity score for the enumeration of mortality and morbidity score.

CONCLUSION: CUSUM techniques provide a potential method of prospective, real-time outcome monitoring in oesophageal cancer surgery.

Frequency of positive surgical margin at prostatectomy and its effect on patient outcome

A positive surgical margin at prostatectomy is defined as tumor cells touching the inked edge of the specimen. This finding is reported in 8.8% to 42% of cases (median about 20%) in various studies. It is one of the main determinants of eventual biochemical (PSA) failure, generally associated with a doubled or tripled risk of failure. The effect of a positive margin on outcome can be modified by stage or grade and the length, number and location of positive margins, as well as by technical operative approach and duration of operator experience. This paper tabulates data from the past decade of studies on margin status.