Enhancing departmental quality control in minimally invasive mitral valve surgery: a single-institution experience

Navigating the challenges of minimally invasive mitral valve surgery: a risk analysis and learning curve evaluation

BACKGROUND

This study aimed to report the risk and learning curve analysis of a minimally invasive mitral valve surgery program performed through a right mini-thoracotomy at a single institution.

METHODS

From January 2013 through December 2019, 266 consecutive patients underwent minimally invasive mitral valve surgery in our department and were included in the current study. Multiple logistic regression analysis was used for the adverse event outcome. Distribution over time of perioperative complications, defined as clinical endpoints in the Valve Academic Research Consortium-2 (VARC-2) consensus document, as well as CUSUM charts for assessment of cardiopulmonary bypass and aortic cross-clamping duration over time, has been performed for learning curve assessment.

RESULTS

Overall incidences of postoperative stroke (1.1%), myocardial infarction (1.1%), and thirty-day mortality (1.5%) were low. The mitral valve reconstruction rate in our series was 95%. Multivariable analysis revealed that concomitant tricuspid valve surgery (OR 4.44; 95%CI 1.61-11.80; p = 0.003) was significantly associated with adverse event outcomes. Despite a trend towards adverse event outcomes in patients with preexisting active mitral valve endocarditis (OR 2.69; 95%CI 0.81-7.87; p = 0.082), mitral valve pathology did not significantly impact postoperative morbidity and mortality. Distribution over time of perioperative complications, defined as clinical endpoints in the VARC-2 consensus document, showed a trend towards an improved complication rate after the initial 65-100 procedures.

CONCLUSIONS

Mitral valve surgery via right-sided mini-thoracotomy can be implemented safely with low perioperative morbidity and mortality rates. Careful patient selection regarding isolated mitral valve surgery in the presence of degenerative mitral valve disease may represent a significant safety issue during the learning curve.

TRIAL REGISTRATION

The cantonal ethics commission of Zurich approved the study (registration ID 2020-00752, date of approval 24 April 2020).

Attaining competency and proficiency in minimally invasive mitral valve repair: a learning curve assessment using cumulative sum analysis

OBJECTIVE

To evaluate the learning curve of minimally invasive mitral valvuloplasty (MVP).

BACKGROUND

Minimally invasive MVP is characterized by minimal trauma, minimal bleeding, and short postoperative recovery time. The learning curve of any new procedure needs to be evaluated for learning and replication. However, minimally invasive mitral valve technique is a wide-ranging concept, no further analysis of the outcomes and learning curve of minimally invasive Mitral valvuloplasty has been performed.

METHODS

One hundred and fifty consecutive patients who underwent minimally invasive MVP alone without concurrent surgery were evaluated. Using cardiopulmonary bypass (CPB) time and aortic clamping (AC) time as evaluation variables, we visualized the learning curve for minimally invasive MVP using cumulative sum analysis. We also analyzed important postoperative variables such as postoperative drainage, duration of mechanical ventilation, ICU stay and postoperative hospital stay.

RESULTS

The slope of the fitted curve was negative after 75 procedures, and the learning curve could be crossed after the completion of the 75th procedure when AC and CPB time were used as evaluation variables. And as the number of surgical cases increased, CPB, AC, postoperative drainage, duration of mechanical ventilation, ICU stay and postoperative hospital stay all showed different degrees of decrease. The incidence of postoperative adverse events is similar to conventional Mitral valvuloplasty.

CONCLUSION

Compared to conventional MVP, minimally invasive MVP provides the same satisfactory surgical results and stabilization can be achieved gradually after completion of the 75th procedure.

Propensity-matched comparison of right mini-thoracotomy versus median sternotomy for isolated mitral valve repair

BACKGROUND

A right mini-thoracotomy (RT) versus median sternotomy (MS) approach for isolated mitral valve (MV) repair has been associated with less postoperative morbidity, shorter hospital stay, and faster functional recovery, but with consistently longer cross-clamp time and higher operative costs.

METHODS

We assessed the impact of a modified operative technique on outcomes in 158 RT versus 129 MS patients treated with myxomatous MV repair from 2016 through 2021. Propensity matching based upon the Society of Thoracic Surgeons Risk Score was used to compare 108 patients in each cohort.

RESULTS

Propensity-matched RT patients had reductions in total ventilation time (P=0.025), postoperative atrial fibrillation (P=0.019), and hospital length of stay (P<0.001). RT and MS patients had similar cross-clamp times (66.4±13.7 vs 64.8±16.0 minutes, P=0.414), with less overall leaflet resection (32.4% vs 57.4%, P<0.001) and fewer Gore-Tex NeoChords implanted per patient (1.7±0.7 vs 2.1±1.0, P=0.028) in the RT group. The two cohorts did not differ with respect to 30-day major surgical complications. No patient died and there was no difference between the two groups with respect to freedom from re-operation (98.2% vs 98.2%, P=0.800) at a mean follow-up of 21.4±18.5 months. Direct total hospital costs were lower for the RT group (P=0.018), with reductions in postoperative charges offsetting increased operating room costs.

CONCLUSIONS

In this single-center study, the RT compared to the MS approach for myxomatous MV repair resulted in less postoperative morbidity and shorter hospital length of stay, with similar cross-clamp time, reduced total hospital costs, and comparable intermediate outcomes.

Effect of Quality Control Program in Surgical Management of Early Cervical Cancer

BACKGROUND

Regular assessments of clinical performance in gynecologic cancer surgery is important for the safety of patients. We evaluated the effects of quality control (QC) program on the treatment pattern and clinical outcomes of early cervical cancer.

METHODS

Medical records of cervical cancer patients who received operation in our institution from January 2007 to December 2018 were retrospectively reviewed. Cases were divided into 2 groups, before and after the initiation of QC program, group 1 (2007-2013) and group 2 (2014-2018), based on the operation date. Two groups were compared in clinicopathologic variables, surgical methods, operative details, adjuvant treatments, recurrence and survival.

RESULTS

A total of 305 cervical cancer patients were included in the analysis, 210 in group 1 and 95 in group 2. In group 2, minimally invasive surgery (MIS) was more frequently performed (60.0% vs. 76.8%, P = 0.004), especially in earlier stages (stage IA, 72.6% vs. 100.0%; stage IB, 52.2% vs. 69.5%). However, the median tumor size treated by MIS was decreased in stage IB (20 mm vs. 17 mm, P = 0.015). Frequency of adjuvant treatment was also reduced in stage IB (56.5% vs. 37.3%, P = 0.016). Recurrence within 3 years, 3-year disease free survival and overall survival did not show significant difference; however, 3-year recurrence after MIS was significantly reduced in stage IB.

CONCLUSION

QC program enforced stricter patient selection criteria for MIS and positively affected clinical outcomes in cervical cancer patients who underwent surgery. Systemic monitoring should be considered for patient safety.

Minimally Invasive Aortic Valve Replacement with Sutureless Valves: Results From an International Prospective Registry

Objective

To report the early and mid-term results of patients who underwent minimally invasive aortic valve replacement (MI-AVR) with a sutureless prosthesis from an international prospective registry.

Methods

Between March 2011 and September 2018, among 957 patients included in the prospective observational SURE-AVR (Sorin Universal REgistry on Aortic Valve Replacement) registry, 480 patients underwent MI-AVR with self-expandable Perceval aortic bioprosthesis (LivaNova PLC, London, UK) in 29 international institutions through either minithoracotomy ( n = 266) or ministernotomy ( n = 214). Postoperative, follow-up, and echocardiographic outcomes were analyzed for all patients.

Results

Patient age was 76.1 ± 7.1 years; 64.4% were female. Median EuroSCORE I was 7.9% (interquartile range [IQR], 4.8 to 10.9). Median cardiopulmonary bypass and cross-clamp times were 81 minutes (IQR 64 to 100) and 51 minutes (IQR 40 to 63). First successful implantation was achieved in 97.9% of cases. Two in-hospital deaths occurred, 1 for noncardiovascular causes and 1 following a disabling stroke. In the early (≤30 days) period, stroke rate was 1.4%. Three early explants were reported: 2 due to nonstructural valve dysfunction (NSVD) and 1 for malpositioning. One mild and 1 moderate paravalvular leak were reported. In 16 patients (3.3%) pacemaker implantation was needed. Mean follow-up was 2.4 years (maximum = 7 years). During follow-up 5 explants were reported, 3 due to endocarditis and 2 due to NSVD. Follow-up stroke rate was 2.5%. Three structural valve deteriorations not requiring reintervention were reported. Five-year survival was 91.45%.

Conclusions

In this large prospective international registry, MI-AVR with Perceval valve confirmed to be safe, reproducible, and effective in an intermediate-risk population, providing excellent clinical recovery both in early and mid-term follow-up.

Transfer of a minimally invasive mitral valve repair program from a high-volume center to a very low volume center: how many cases are necessary to maintain acceptable results?

OBJECTIVE

To investigate whether minimally invasive mitral valve repair (MIMVR) can be transferred from a high-volume center into a very small volume center and to clarify how many cases are necessary for maintenance of this program, early outcomes of MIMVR in Asahikawa Medical University were compared with those results in patients operated by a single surgeon in Duesseldorf University Hospital.

METHODS

Sixty-five patients who underwent MIMVR in Asahikawa Medical University (group A) between May 2014 and July 2018 and 134 patients who underwent MIMVR in Duesseldorf University Hospital (group D) between September 2009 and January 2014 by a surgeon who started MIMVS later in Asahikawa were retrospectively analyzed.

RESULTS

In group D, there were more patients with ischemic mitral valve regurgitation and with annular calcification than in group A. Survival rate at 6 months and 1 year was 98.5% and 98.5% in group A and 92.9% and 91.3% in group D, respectively. EuroSCORE II was significantly higher in patients dead within 30 days and within the first year.

CONCLUSIONS

The present study demonstrated that MIMVR programs can be transferred with acceptable early results into very low volume centers, if the team is developed by surgeons who are well trained and experienced in MIMVR. Moreover, the present study suggested that case number for maintenance of acceptable results may be obviously less than the previous recognition that this kind of specialized surgery could be maintained with at least 50 cases annually. However, meticulous preparations for surgery are essential for satisfactory surgical outcomes.

Transapical NeoChord mitral valve repair

Transapical off-pump mitral valve repair (MVr) with NeoChord implantation has become widely applied in Europe for patients presenting with severe mitral regurgitation due to leaflet prolapse or flail. The procedure is performed under real-time 2D- and 3D-transesophageal echocardiography (TEE) for both implantation and neochordae tension adjustment allowing real-time monitoring of hemodynamic recovery. Preoperative anatomic and echocardiographic selection criteria, procedure refinement, as well as innovative ex-vivo surgical simulator training have been developed and strategically employed in the past few years, to generate a robust precision-based procedural framework with significantly enhanced operator use, patient safety and clinical outcomes. The procedure has evolved into a reproducibly successful and safe approach, which complements existing surgical treatment strategies available to eligible patients with chronic severe degenerative mitral regurgitation.

Antegrade and retrograde perfusion in minimally invasive mitral valve surgery with transthoracic aortic clamping: a single-institution experience with 1632 patients over 12 years

Objectives

The aim of the present study was to evaluate the impact of a retrograde arterial perfusion (RAP) strategy versus an antegrade arterial perfusion (AAP) strategy in a consecutive, large cohort of patients who underwent minimally invasive mitral valve surgery with transthoracic aortic clamping through a right minithoracotomy.

Methods

Between 2003 and 2015, 1632 consecutive patients underwent first-time minimally invasive mitral valve surgery with transthoracic aortic clamping at our institution; 141 (8.6%) of these patients received retrograde perfusion with femoral artery cannulation, whereas 1421 (91.4%) received antegrade perfusion with ascending aorta cannulation. Logistic regression was used to evaluate outcomes and risk factors for death and stroke between groups.

Results

The overall frequency of 30-day mortality was 0.7% (13/1632) and was similar between groups (retrograde arterial perfusion RAP 0.7% vs AAP 0.8%; P  = 0.903). The overall postoperative stroke rate was 1.3% (22/1632). The stroke rate was significantly higher in patients receiving retrograde perfusion (3.5% vs 1.1%; P  = 0.005). Risk factors for death were advanced age (odds ratio (OR) = 1.3; P  = 0.004), mitral valve replacement (OR = 3.9; P  = 0.05), emergent procedure (OR = 3.4; P  = 0.014) and conversion to sternotomy (OR = 3.7; P  = 0.001). Multivariable regression analysis revealed that retrograde perfusion was an independent risk factor for stroke (OR = 3.3; P  = 0.004). Other risk factors were conversion to sternotomy (OR = 12; P  = 0.001), active endocarditis (OR = 5.8; P  = 0.07) and hypercholesterolaemia (OR = 2.4; P  = 0.048). Interaction modelling revealed that the only significant risk factor for a neurological event was the use of retrograde perfusion in patients older than 70 years with an atherosclerotic burden (OR = 6.4; P  = 0.033).

Conclusions

Minimally invasive mitral valve procedures can be performed with low morbidity and mortality. The use of retrograde perfusion is associated with a higher incidence of neurological complications in older patients with atherosclerotic burden. Central aortic cannulation permits avoidance of complications associated with retrograde perfusion and extends the suitability of minimally invasive mitral procedures to those patients who have an absolute contraindication for femoral artery cannulation.

Minimally invasive mitral valve surgery through a right mini-thoracotomy

Since its introduction in the mid-1990s, minimally invasive mitral valve surgery (MIMVS) has been shown to be a feasible alternative to a conventional full-sternotomy approach, and several studies have reported excellent clinical outcomes with low perioperative morbidity and mortality. As a result, MIMVS is being increasingly employed as a routine procedure worldwide. On the other hand, several issues have been raised, including complications specific to this technique and its steep learning curve, while there are also concerns regarding the durability of a mitral valve repair through a limited access. In this study, the current status and future perspectives of MIMVS were examined.

Exploring the learning curve for minimally invasive sutureless aortic valve replacement

OBJECTIVE

The study objective was to assess the learning process and quality of care of right minithoracotomy aortic valve replacement with a sutureless bioprosthesis at a single institution.

METHODS

We performed an analysis of the first 300 consecutive patients (aged 76 ± 6 years; logistic European System for Cardiac Operative Risk Evaluation 9 ± 6) who underwent sutureless valve implantation via a right minithoracotomy by 6 surgeons at the G. Pasquinucci Heart Hospital between 2011 and 2015. The learning curve was analyzed by dividing the study population into tertiles of 100 patients each. Departmental and individual learning curves were calculated using sequential probability cumulative sum failure analysis. Quality indicators were 2 composite end points reflecting the technical success and 30-day complications.

RESULTS

The overall mortality was 0.7% (2 patients). No significant differences were noted in terms of mortality and complications between tertiles. The sutureless valve was implanted successfully in 99% of patients (298/300). Cumulative sum analysis failed to identify any significant learning effects for technical success. Nevertheless, surgeons A, B, and C had a small initial learning curve, and surgeons D, E, and F did not, reflecting a trend toward a positive effect of cumulative institutional experience on the individual learning curve. The 30-day complications analysis revealed a cluster of failures at the beginning of the experience. This cluster prompted an internal audit and modification of the patients' selection process. Consecutively, the procedure returned in control.

CONCLUSIONS

Right minithoracotomy sutureless valve implantation can be performed safely without learning curve effects. Cumulative sum analysis is a valuable tool to describe and monitor the learning process. The analysis can identify periods of less than expected performance and alert the team to react.

Early and long-term outcomes of minimally invasive mitral valve surgery through right minithoracotomy: a 10-year experience in 1604 patients

Background

To report early and long-term outcomes of patients undergoing minimally invasive mitral valve surgery (MIMVS) through right mini-thoracotomy (RT) over a 10-year period.

Methods

From September 2003 to December 2013, a total of 1604 consecutive patients underwent MIMVS through RT.

Results

The mean age was 63 ± 13 years, 770 (48 %) patients were female and 218 (13.6 %) had previous cardiac operations. The most predominant pathology was degenerative disease (70 %), followed by functional mitral valve regurgitation (12 %), rheumatic disease (9.4 %), endocarditis (5 %) and prosthetic dysfunction (3.2 %). Mitral valve repair was performed in 1137 (71 %) patients and 476 (29 %) had mitral valve replacement. Direct aortic cannulation was achieved in 1325 (83 %) patients. Among patients with degenerative disease candidate for repair (n = 958), rate of mitral valve repair was 95 %. Repair techniques included annuloplasty (95 %), leafleat resection (63 %), neochordae implantation (16 %) and sliding plasty (11 %). Concomitant procedures included tricuspid valve repair (14.6 %), atrial fibrillation ablation (9.5 %) and atrial septal defect closure (3.2 %). Overall in-hospital mortality was 1.1 %. Thirty-four patients (2.1 %) had conversion to sternotomy. Incidence of stroke was 2 %. Overall survival at 10 years was 88 ± 2 %. Freedom from reoperation at 10 years was 94 ± 2 % for repair and 80 ± 6 % for replacement. Freedom from recurrent mitral regurgitation >3+ at 10 years was 90 ± 3 %.

Conclusions

Minimally invasive mitral valve surgery is a safe and reproducible approach associated with low mortality and morbidity, high rate of mitral valve repair and excellent late results.

Cost-Benefit Analysis of Robotic versus Nonrobotic Minimally Invasive Mitral Valve Surgery

Objective

To date, a direct comparison of minimally invasive mitral valve repair or replacement (mini-MVR) versus robotic MVR is lacking; therefore, the purpose of this study was to address this deficit and compare mini-MVR with robotic MVR from a cost-benefit perspective.

Methods

From a total of 759 literature citations, 21 studies were included for statistical comparisons of benefit outcomes, whereas 3 studies and our institutional experience were used to compare costs.

Results

The total cost per case exceeding that of conventional MVR is approximately $2063.90 for robotic MVR and $271 for mini-MVR. Mean 30-day mortality rates for mini-MVR and robotic MVR groups were 1.24% and 0.55%, respectively [106/8548 vs 6/1089; odds ratio (OR), 2.27; P = 0.052]. The conversion rate to conventional MVR was 0.77% in mini-MVR and 1.83% in robotic MVR (35/5092 vs 22/1046; OR, 0.32; P < 0.001). The rate of neurologic events was 1.32% in mini-MVR and 2.37% in robotic MVR (109/8257 vs 20/845; OR, 0.55; P = 0.02). Postoperative atrial fibrillation was seen in 11.42% of mini-MVR patients and in 19.67% of robotic MVR patients (371/3249 vs 203/1032; OR, 0.53, P < 0.001). Mean cardiopulmonary bypass time was longer in mini-MVR (137.4 vs 130.4 minutes), whereas cross-clamp time was shorter (82.2 vs 96.7 minutes).

Conclusions

Our comparative analysis provides insights into the clinical benefits versus variable costs relationship related to mini-MVR and robotic MVR.

Very high repair rate using minimally invasive surgery for the treatment of degenerative mitral insufficiency

BACKGROUND

Minimally invasive mitral valve surgery (MIMVS) is an established alternative to median sternotomy for mitral valve repair. However, this technique has yet to gain widespread adoption, partly because of concerns that this approach might yield lower repair rates or repairs that are less durable than those performed through a sternotomy. The purpose of this study was to report our inaugural experience with MIMVS, with a focus on mitral valve repair rate and midterm outcomes.

METHODS

Between May 2006 and April 2012, minimally invasive mitral valve repair was attempted in 200 consecutive patients with degenerative mitral disease. The approach used was a 4- to 5-cm right anterolateral minithoracotomy with femorofemoral cannulation for cardiopulmonary bypass. Mean follow-up was 2.9 ± 1.8 years, and follow-up was 99% complete.

RESULTS

The mitral valve was successfully repaired in all but 2 patients, yielding a repair rate of 99%. Hospital mortality occurred in 2 patients (1%). Intraoperative conversion to sternotomy was necessary in 12 patients (6%), including 1 of the 2 unsuccessful repairs. Mean cardiopulmonary bypass and aortic cross-clamp times were 130.8 ± 41.3 minutes and 104.8 ± 35.6 minutes, respectively. Median hospital stay was 5 days. The 5-year survival and freedom from reoperation were 97.9% ± 1.5% and 98.1% ± 1.3%, respectively.

CONCLUSIONS

A very high repair rate can be achieved using MIMVS for the treatment of degenerative mitral regurgitation, including during the learning phase. Midterm survival and freedom from valve-related reoperation are excellent. MIMVS is a safe and effective alternative to mitral valve repair through a sternotomy.

Training surgeons in minimally invasive mitral valve repair: a single institution experience

BACKGROUND

We aimed to study the results of minimally invasive mitral valve repair performed by 5 young surgeons who were trained in mitral valve repair directly through a minimally invasive approach, and a senior surgeon who introduced the technique at our institution and was responsible for the training program.

METHODS

This was a retrospective, observational cohort study of prospectively collected data from 595 consecutive patients who underwent minimally invasive mitral repair performed by 5 trainees (n = 240, 40.3%) and by our lead consultant (n = 355, 59.7%) between 2007 and 2013. Treatment selection bias was controlled by constructing a propensity score from core patient characteristics and it was included along with the comparison variable in the multivariable analyses of outcome.

RESULTS

Patients operated on by trainees were more likely to be female (p = 0.04), older (p = 0.001), and with history of atrial fibrillation (p = 0.001). Trainees required a significant longer cardiopulmonary bypass (137 ± 56 vs 123 ± 52 minutes; p = 0.003) and aortic clamp time (97 ± 41 vs 83 ± 40 minutes; p = 0.001). I-hospital mortalities were 1.3% in the trainees group and 0.8% in the senior surgeon group (p = 0.6). The incidence of stroke (1.7% vs 2.5%; p = 0.5), conversion to sternotomy (2.6% vs 3.5%; p = 0.5), and conversion to mitral valve replacement (12.5% vs 10.9%; p = 0.6) were similar between groups. No differences were found regarding other complications. Five-year survival (88.9% vs 89.5%; p = 0.4) and freedom from reoperation (94.5% vs 95.1; p = 0.6) were similar between groups.

CONCLUSIONS

Minimally invasive mitral valve repair is a safe and reproducible surgical technique that can be taught successfully to cardiac trainees.

Enhancing quality control and performance monitoring in thoracic aortic surgery: a 10-year single institutional experience

OBJECTIVES

The aim of the present study was to monitor performance and learning effects for thoracic aortic surgery. In addition, we evaluated the volume-outcome relationship of patients undergoing surgery of the thoracic aorta, comparing the results of two higher-volume surgeons (HVSs) with six lower volume surgeons.

METHODS

A total of 867 thoracic aortic procedures (elective cases n = 753 and Type A acute dissection n = 114) were performed from 2003 to 2013 by eight surgeons (range 28-238 procedures) at our institution. Departmental and individual performance was monitored using control charts, with a predetermined acceptable failure rate of 10%. Perioperative death or one or more of four adverse events constituted failure. Moreover, results of two higher-volume operators (n = 460; 53%) were compared with those of six lower-volume operators (n = 407; 47%).

RESULTS

The incidence rate of in-hospital mortality for elective cases was 2% and for Type A dissection repair 9.6%. Institutional control charts revealed that the surgical process was under control for all the study periods apart from small periods of worse than expected performance which were congruent with new surgeons joining the programme. The predominant surgical failure was reoperation for bleeding. There were differences between surgeons with regard to the learning curves and performance. No significant differences were observed between high- and low-volume surgeons in terms of mortality and morbidity for elective cases. However, high-volume surgeons presented a trend suggesting a higher mortality rate in Type A aortic dissection repair (17.1 vs 6.3%; P = 0.09).

CONCLUSIONS

Thoracic aortic surgery can be performed with similar results by high- and low-volume surgeon. Control charts can facilitate learning effects and performance monitoring. Implementation of continuous departmental and individual performance monitoring is practicable.

Application of the statistical process control method for prospective patient safety monitoring during the learning phase: robotic kidney transplantation with regional hypothermia (IDEAL phase 2a-b)

BACKGROUND

Traditional evaluation of the learning curve (LC) of an operation has been retrospective. Furthermore, LC analysis does not permit patient safety monitoring.

OBJECTIVES

To prospectively monitor patient safety during the learning phase of robotic kidney transplantation (RKT) and determine when it could be considered learned using the techniques of statistical process control (SPC).

DESIGN, SETTING AND PARTICIPANTS

From January through May 2013, 41 patients with end-stage renal disease underwent RKT with regional hypothermia at one of two tertiary referral centers adopting RKT. Transplant recipients were classified into three groups based on the robotic training and kidney transplant experience of the surgeons: group 1, robot trained with limited kidney transplant experience (n=7); group 2, robot trained and kidney transplant experienced (n=20); and group 3, kidney transplant experienced with limited robot training (n=14).

INTERVENTION

We employed prospective monitoring using SPC techniques, including cumulative summation (CUSUM) and Shewhart control charts, to perform LC analysis and patient safety monitoring, respectively.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Outcomes assessed included post-transplant graft function and measures of surgical process (anastomotic and ischemic times). CUSUM and Shewhart control charts are time trend analytic techniques that allow comparative assessment of outcomes following a new intervention (RKT) relative to those achieved with established techniques (open kidney transplant; target value) in a prospective fashion.

RESULTS AND LIMITATIONS

CUSUM analysis revealed an initial learning phase for group 3, whereas groups 1 and 2 had no to minimal learning time. The learning phase for group 3 varied depending on the parameter assessed. Shewhart control charts demonstrated no compromise in functional outcomes for groups 1 and 2. Graft function was compromised in one patient in group 3 (p<0.05) secondary to reasons unrelated to RKT. In multivariable analysis, robot training was significantly associated with improved task-completion times (p<0.01). Graft function was not adversely affected by either the lack of robotic training (p=0.22) or kidney transplant experience (p=0.72).

CONCLUSIONS

The LC and patient safety of a new surgical technique can be assessed prospectively using CUSUM and Shewhart control chart analytic techniques. These methods allow determination of the duration of mentorship and identification of adverse events in a timely manner. A new operation can be considered learned when outcomes achieved with the new intervention are at par with outcomes following established techniques.

PATIENT SUMMARY

Statistical process control techniques allowed for robust, objective, and prospective monitoring of robotic kidney transplantation and can similarly be applied to other new interventions during the introduction and adoption phase.

Rate of repair in minimally invasive mitral valve surgery

BACKGROUND

Valve repair has been shown to be the method of choice in the treatment of patients with severe mitral valve regurgitation. Minimally invasive surgery has raised skepticism regarding the rate of repair especially for supposedly complex lesions, when anterior leaflet involvement or bileaflet prolapse is present. We sought to review our experience of all our patients presenting with degenerative mitral valve regurgitation and operated on minimally invasively.

METHOD

From September 2006 to December 2012, 842 patients (mean age 56.12±11.62 years old) with degenerative mitral valve regurgitation and anterior leaflet (n=82, 9.7%), posterior leaflet (n=688, 81.7%) and bileaflet (n=72, 8.6%) prolapses were operated on using a minimally invasive approach.

RESULTS

836 patients had a valve repair (99.3%) and received a concomitant ring annuloplasty (mean size, 33.7; range, 28-40). Six patients (0.7%) underwent valve replacement. Two patients had a re-repair due to MR progression or infective endocarditis. Thirty-day mortality was 0.2% (two patients). There were 60 major adverse events (MAE) (7.1%).

CONCLUSIONS

A minimally invasive approach allows repair of almost all degenerative valves with good short-term outcomes in a tertiary referral center, when using proven and efficient surgical techniques.