A model for delivery of extracorporeal life support in a stand-alone veterans affairs medical center.

INTRODUCTION: For the Veterans Health Administration (VHA) to continue to perform complex cardiothoracic surgery, there must be an established pathway for providing urgent/emergent extracorporeal life support (ECLS). Partnership with a nearby tertiary care center with such expertise may be the most resource-efficient way to provide ECLS services to patients in post-cardiotomy cardiogenic shock or respiratory failure. The goal of this project was to assess the efficiency, safety, and outcomes of surgical patients who required transfer for perioperative ECLS from a single stand-alone Veterans Affairs Medical Center (VAMC) to a separate ECLS center. METHODS: Cohort consisted of all cardiothoracic surgery patients who experienced cardiogenic shock or refractory respiratory failure at the local VAMC requiring urgent or emergent institution of ECLS between 2019 and 2022. The primary outcomes are the safety and timeliness of transport. RESULTS: Mean time from the initial shock call to arrival at the ECLS center was 2.8 h. There were no complications during transfer. Six patients (86%) survived to decannulation. CONCLUSION: These results suggest that complex cardiothoracic surgery can be performed within the VHA system and when there is an indication for ECLS, those services can be safely and effectively provided at an affiliated, properly equipped center.

Peripherally inserted concomitant surgical right and left ventricular support, the Propella, is associated with low rates of limb ischemia, with mortality comparable with peripheral venoarterial extracorporeal membrane oxygenation.

BACKGROUND: Mechanical circulatory support effectively treats adult cardiogenic shock. Whereas cardiogenic shock confers high mortality, acute limb ischemia is a known complication of mechanical circulatory support that confers significant morbidity. We compared our novel approach to peripheral mechanical circulatory support with a conventional femoral approach, with a focus on the incidence of acute limb ischemia. METHODS: This was a retrospective cohort study of patients treated with mechanical circulatory support between January 1, 2015 and December 5, 2021 at our institution. Patients receiving any femoral peripheral venoarterial extracorporeal membrane oxygenation were compared with those receiving minimally invasive, peripherally inserted, concomitant right and left ventricular assist devices. These included the Impella 5.0 (Abiomed, Danvers, MA) left ventricular assist device and the ProtekDuo (LivaNova, London, UK) right ventricular assist device used concomitantly (Propella) approach. The primary outcome was incidence of acute limb ischemia. The baseline patient characteristics, hemodynamic data, and post-mechanical circulatory support outcomes were collected. Fisher exact test and Wilcoxon rank sum test was used for the categorical and continuous variables, respectively. Kaplan-Meier curves and log-rank test were used to estimate overall survival probabilities and survival experience, respectively. RESULTS: Fifty patients were treated with mechanical circulatory support at our institution for cardiogenic shock, with 13 patients supported with the novel Propella strategy and 37 with peripheral venoarterial extracorporeal membrane oxygenation. The baseline characteristics, including patient organ function and medical comorbidities, were similar among the groups. Nine patients suffered mortality in ≤48 hours of mechanical circulatory support initiation and were excluded. Twenty patients (69%) suffered acute limb ischemia in the peripheral venoarterial extracorporeal membrane oxygenation group; 0 patients receiving Propella suffered acute limb ischemia (P < .001). The percentages of patients surviving to discharge in peripheral venoarterial extracorporeal membrane oxygenation and Propella groups were 24% and 69%, respectively (P = .007). CONCLUSION: Patients treated with the Propella experienced a lower incidence of acute limb ischemia compared with patients treated with peripheral venoarterial extracorporeal membrane oxygenation.

Adhered ECMO cannula in COVID-19 related severe acute respiratory failure.

BACKGROUND: Crescent cannula adhesion in the setting of COVID-19 respiratory failure requiring extracorporeal membrane oxygenation (ECMO) support is a novel complication. The objective of this case presentation is to highlight this rare complication and to explore potential predisposing factors and our management strategies. CASE PRESENTATION: We present the case of a 25 y.o. patient with COVID-19 respiratory failure requiring ECMO support for 16-days in which a 32 Fr crescent cannula became adherent to the SVC and proximal jugular vein. Attempts to remove the cannula at the bedside failed due to immobility of the cannula. Ultrasound of the right neck was unremarkable, so he was taken to the hybrid OR where both TEE and fluoroscopy were unrevealing. An upper sternotomy was performed, and the superior vena cava and proximal jugular vein were dissected revealing a 2 cm segment of the distal SVC and proximal jugular vein that was densely sclerosed and adherent to the cannula. The vessel was opened across the adherent area at the level of the innominate vein and the cannula was then able to be withdrawn. The patient suffered no ill effects and had an unremarkable recovery to discharge. CONCLUSIONS: To date, there have been no reports of crescent cannula adhesion related complications. In patients with COVID-19 respiratory failure requiring ECMO, clinicians should be aware of widespread hypercoagulability and the potential of unprovoked, localized venous sclerosis and cannula adhesion. We report our technique of decannulation in the setting of cannula adhesion and hope that presentation will shed further light on this complication allowing clinicians to optimize patient care.

How Does Multiple Listing Affect Lung Transplantation? A Retrospective Analysis.

The impact of multiple listing (ML) strategies on lung transplantation is unknown. Retrospective review of United Network for Organ Sharing (UNOS) registry for lung transplantation between May 1, 2005 and March 31, 2017 was performed. Characteristics of single (SL) and ML candidates were compared, and incidence density matching was used to select up to 10 controls for each case. Overall survival was evaluated using Cox regression stratified by matched sets. Nelson-Aalen estimators were used to estimate the cumulative incidence (CI) of transplant, death on the waiting list, and removal from wait-list as competing risks; Gray's test was used to compare wait list outcomes between groups. 23,445 subjects listed for lung transplant, of which 467 (2%) subjects listed at 2+ centers; 206 matched sets. There was no difference in overall survival of matched cases and controls at 1 year (ML 83.7%, SL 90.2%), 3 years (ML 63.9%, SL 68%), and 5 years (ML 51.9%, SL 49.3%) (p=0.24). The CIs of receiving a lung transplant at 2 years for ML and SL were 83.6% and 71%, respectively. Multi-listing increased the probability of receiving a transplant (p<0.001) but was not associated with waitlist mortality (p=0.13). There was no difference in post-transplant survival between ML and SL candidates (HR=0.82, p=0.32). ML was associated with a substantial increase in probability of lung transplantation, but there was no difference in overall survival, post-transplant, or wait-list mortality. Our study permits more informed decision-making for patients considering the ML strategy.

Venovenous Extracorporeal Membrane Oxygenation to Facilitate Removal of Endobronchial Tumors.

Short-term extracorporeal membrane oxygenation is a useful adjunct to thoracic procedures. We report the cases of 2 middle-aged men who were supported with venovenous extracorporeal membrane oxygenation to facilitate tumor debulking and recanalization of the carina and mainstem bronchi. Neither patient had major complications or adverse events. These cases suggest that short-term extracorporeal membrane oxygenation is safe in patients undergoing complex resection or debulking of endobronchial lesions.

Temporary mechanical circulatory support prevents the occurrence of a low-output state in high-risk coronary artery bypass grafting: A case series.

BACKGROUND: Coronary artery bypass grafting (CABG) is a durable treatment for coronary artery disease. Left ventricular dysfunction (LVD) (a division of cardiothoracic surgery) (ejection fraction < 35%) significantly elevates perioperative risk for patients pursuing surgical revascularization. Periprocedural support with temporary mechanical circulatory support (tMCS) has shown benefit in this patient population. METHODS: Four patients with ischemic cardiomyopathy and LVD underwent CABG at our institution between 2017 and 2018. Each patient received perioperative ventricular support using a microaxial tMCS device (Impella 5.0®). The occurrence of a postoperative low-output state (LOS) was assessed for as well as postoperative morbidity and mortality, device-specific complications, and tMCS support duration. RESULTS: All patients survived to device explant without device-related complications. Two patients required reoperation for nondevice-related bleeding. All patients were without an LOS at 24 h postoperatively with cardiac indices of 2.9-3.6 L/min/m2 , normalized serum lactate, and vasoactive-inotrope scores of 0-12.0. There was a notably high incidence of acute renal failure (50%), which was observed in patients with preoperative cardiogenic shock. One patient died 10 days after the device explant. Of the three patients that survived to discharge, two were alive at the most recent follow-up. Postoperative device support varied widely (0-500 h). CONCLUSION: Perioperative tMCS may be a viable strategy for preventing postoperative LOS in high-risk CABG patients with a low complication rate and acceptable morbidity. The application of microaxial tMCS devices in CABG is an area that warrants further investigation to delineate its impact on perioperative outcomes and potentially expand the indications for such devices.

A Dual-Lumen Percutaneous Cannula for Managing Refractory Right Ventricular Failure.

A right ventricular assist device (RVAD) using a dual-lumen percutaneous cannula inserted through the right internal jugular vein (IJV) might improve weaning in patients with refractory right ventricular (RV) failure. However, the reported experience with this cannula is limited. We reviewed the records of all patients receiving RVAD support with this new dual-lumen cannula at our institution between April 2017 and February 2019. We recorded data on weaning, mortality, and device-specific complications. We compared outcomes among three subgroups based on the indications for RVAD support (postcardiotomy, cardiogenic shock, and primary respiratory failure) and against similar results in the literature. Mean (standard deviation [SD]) age of the 40 patients (29 men) was 53 (15.5) years. Indications for implantation were postcardiotomy support in 18 patients, cardiogenic shock in 12, and respiratory failure in 10. In all, 17 (94%) patients in the postcardiotomy group were weaned from RVAD support, five (42%) in the cardiogenic shock group, and seven (70%) in the respiratory failure group, overall higher than those reported in the literature (49% to 59%) for surgically placed RVADs. Whereas published in-hospital mortality rates range from 42% to 50% for surgically placed RVADs and from 41% to 50% for RVADs with percutaneous cannulas implanted through the right IJV, mortality was 11%, 58%, and 40% in our subgroups, respectively. There were no major device-related complications. This percutaneous dual-lumen cannula appears to be safe and effective for managing refractory RV failure, with improved weaning and mortality profile, and with limited device-specific adverse events.

Cryopreserved Saphenous Vein Compared With PTFE Graft for Use as Modified Blalock-Taussig or Central Shunt in Cyanotic Congenital Heart Disease.

Many infants with congenital heart disease undergo palliative shunt procedures. In our center, cryopreserved saphenous vein and polytetrafluoroethylene (PTFE) are used as grafts to construct these shunts. In this retrospective review, we compare morbidity, mortality, and freedom from reoperation associated with the use of these graft materials. We conducted a retrospective study of 136 consecutive patients who were palliated with shunts between 2006 and 2015. A total of 136 patients were identified, 9 had incomplete data; thus, 127 patients were included: 69 saphenous and 58 PTFE. The cohorts were matched with respect to birth weight, gestational age, age and weight at time of surgery, and underlying cardiac condition. There were 15 (12%) deaths in the study cohort with no intraoperative mortality. Thrombosis was seen in 5.2% (2/38) of the saphenous modified Blalock-Taussig shunt (mBTS) group and 20.6% (14/68) of those with PTFE mBTS. There was no thrombosis in the central shunt group. Freedom from reoperation was 83% in the saphenous vein group and 81% in the PTFE group. There was no difference in overall morbidity or mortality, although thrombosis was significantly less in the saphenous vein group. Cryopreserved saphenous vein is a safe alternative, either as a mBTS or as a central shunt.

Durability of central aortic valve closure in patients with continuous flow left ventricular assist devices.

BACKGROUND: A competent aortic valve is essential to providing effective left ventricular assist device support. We have adopted a practice of central aortic valve closure by placing a simple coaptation stitch at left ventricular assist device implantation in patients with significant aortic insufficiency. We conducted a follow-up study to evaluate the efficacy and durability of this procedure. METHODS: The study included patients who had undergone continuous flow left ventricular assist device implantation. The patients were divided into 2 groups, those who did not require any aortic procedure because the valve was competent and those who underwent central aortic valve closure for mild or greater aortic regurgitation. The clinical endpoints were mortality, progression or recurrence of aortic insufficiency, and reoperation for aortic valve pathologic features. Aortic insufficiency was measured qualitatively from mild to severe on a scale of 0 to 5. RESULTS: A total of 123 patients received continuous flow left ventricular assist devices from February 2007 to August 2011. Of those, 18 (15%) underwent central aortic valve closure at left ventricular assist device implantation because of significant aortic insufficiency (1.8 ± 1.4) and 105 who did not (competent aortic valve, 0.15 ± 0.43; P < .01). At follow-up (median, 312 days; range, 0-1429 days), the mean aortic insufficiency score remained low for the patients with central aortic valve closure (0.27 ± 0.46) in contrast to those without central aortic valve closure who experienced aortic insufficiency progression (0.78 ± 0.89; P = .02). In addition, the proportion of patients with more than mild aortic insufficiency was significantly less in the central aortic valve closure group (0% vs 18%; P = .05). The patients in the central aortic valve closure group were significantly older and had a greater incidence of renal failure at baseline. The 30-day mortality was greater in the central aortic valve closure group, but the late survival was similar between the 2 groups. No reoperations were required for recurrent aortic insufficiency. CONCLUSIONS: The results of our study have shown that repair of aortic insufficiency with a simple central coaptation stitch is effective and durable in left ventricular assist device-supported patients, with follow-up extending into 2 years. Although aortic insufficiency progressed over time in those with minimal native valve regurgitation initially, no such progression was noted in those with central aortic valve closure. Additional investigation is needed to evaluate whether prophylactic central aortic valve closure should be performed at left ventricular assist device implantation to avoid problematic aortic regurgitation developing over time, in particular in patients undergoing left ventricular assist device implantation for life-long (destination therapy) support.

Reoperation after arterial switch: a 27-year experience.

BACKGROUND: The long-term outcome and spectrum of reoperation after the arterial switch operation (ASO) has not been fully defined, and there are limited data in the literature. We reviewed our institutional experience with reoperation(s) after ASO. METHODS: Between January 1984 and January 2012, 32 patients (23 male) underwent reoperation(s) after ASO. Anatomy included simple transposition of the great arteries in 14, complex transposition of the great arteries in 14, and Taussig-Bing in 4. Mean age was 6.7 ± 1.4 years at first operation and 10.8 ± 13.4 years at the second operation. Isolated pathology was present in 11 (34.3%) and multiple pathologies in 21 (65.6%). Abnormalities at first reoperation were right-sided pathology in 18 (56.3%), left-sided pathology in 10 (31%), coronary artery in 3 (9%), mitral valve in 3 (9%), residual ventricular septal defect in 4 (12.5%), and recoarctation in 2 (6.3%). It was the second reoperation in 12 and the third reoperation in 3 patients. RESULTS: The first reoperation included pulmonary artery patch plasty in 18, aortic valve operation in 8 (4 valve replacement, 3 root replacement, and 1 repair), pulmonary valve replacement in 4, coronary artery bypass grafting in 3, and mitral valve repair in 3. Multiple reoperations occurred in 15 patients, comprising right-sided procedures (11), left-sided (2), and other (2). Pulmonary artery reconstruction occurred earlier than neoaortic intervention (5.4 ± 6.8 vs 13.8 ± 7.7 years, p < 0.001). There were 2 early deaths (6.2%); both patients had complex transposition of the great arteries and both were at early reoperation after ASO. Median follow-up was 14.5 years (maximum, 27 years). There were no late deaths. Freedom from reoperation at 1, 5, and 15 years was 88%, 78%, and 41%, respectively. CONCLUSIONS: The most common indication for reoperation after ASO is right-sided pathology, followed by neoaortic root pathology. Late survival after ASO is excellent and risk of late reoperation is low. Life-long medical surveillance is required.

Concomitant tricuspid valve repair or replacement during left ventricular assist device implant demonstrates comparable outcomes in the long term.

INTRODUCTION: Severe tricuspid regurgitation (TR) is present in nearly half the patients undergoing implant of a left ventricular assist device (LVAD) and its correction confers better long-term outcome. AIM: To compare the early and late results of tricuspid valve repair (TVrpr) or replacement (TVR) with LVAD implant. PATIENT AND METHODS: Sixty-four from a cohort of 126 patients had a concomitant tricuspid valve procedure; 48 (75%) underwent a TVrpr whereas 16 (25%) had TVR. All preoperative hemodynamic parameters including the mean TR grade (TVrpr; 3.6 vs. TVR; 3.7) were comparable (p = 0.7). The mean TR grade was 1.6 ± 1.5 for the remaining 62 patients who did not have a concomitant tricuspid valve procedure, with 4/62 (6%) having severe TR (p < 0.0001). RESULTS: Cardiopulmonary bypass time was longer for patients undergoing TVR (p = 0.01). There was a significant reduction in right atrial pressure for the entire cohort (p < 0.01) and the postoperative right atrial pressure was not statistically different between TVrpr (13.6 ± 4.6) and TVR (11.6 ± 4.3; p = 0.6. Postoperative intensive care unit stay was comparable as was the duration of inotropic support (p = 0.5) or need for temporary right ventricular mechanical support. In-hospital mortality (12%) was not different between groups. The mean time for LVAD support was 12.3 ± 9.71 months and the last transthoracic echocardiographic examination was performed at mean intervals of 13.8 ± 10.8 months (TVrpr) and 11.8 ± 7.6 months (TVR; p = 0.47). Reduction in TR grade was similar between groups (p = 0.27). Late mortality (p = 1.00) was comparable in both groups. Using log-rank analysis, there was no significant difference in the estimated survival between TVrpr and TVR (p = 0.88). CONCLUSION: TVrpr repair at the time of LVAD implant is effective in correcting TR even at the end of one year of follow-up. The choice to repair or replace does not affect the clinical outcome.

Driveline infections in left ventricular assist devices: implications for destination therapy.

BACKGROUND: Infection is one of the major limitations to successful long-term support after ventricular assist device implantation. There are limited data specifically examining the incidence and predictors of driveline infections (DLI), with a changing treatment paradigm toward destination therapy (DT) and longer duration of support. METHODS: Between January 2007 and 2011, 143 patients underwent HeartMate II (Thoratec, Pleasanton, CA) implantation, with 87 (61%) as DT. Driveline maintenance strategy included sterile dressing changes with chlorhexidine and saline application, without prophylactic oral antibiotics. RESULTS: DLI developed in 18 patients (12%) at a median of 182 days (range, 26 to 1,138 days) after implantation, among which 12 (66%) were from the DT cohort. Infections were superficial in 15 (82%) and deep in 3 (18%). Trauma was documented in 6 patients (33%). Seven patients (38%) needed readmission for DLI. Surgical debridement was needed in 3 (17%). All patients were managed successfully, without the need for device explantation or urgent cardiac transplantation. No patient required continuous antibiotic prophylaxis after the infection subsided. Risk factor analysis identified duration of support as the only independent predictor of infection (mean. 600 vs 390 days; p = 0.03). The odds of having a DLI rose by 4% for every month of support. CONCLUSIONS: Longer duration of support significantly increased the risk of DLI and hence increased the risk of DLI in patients with DT. DLI may be successfully managed with antibiotics and local wound care. Most of the infections were superficial, and progression to deep pocket or pump infection is rare in our experience.

Ventricular fibrillation in an ambulatory patient supported by a left ventricular assist device: highlighting the ICD controversy.

Left ventricular assist devices (LVADs) provide an effective means of managing advanced pump failure as a means of bridging to cardiac transplantation or as permanent therapy. Although ventricular arrhythmias remain common post-LVAD implantation, such therapy may allow malignant arrhythmias to be tolerated hemodynamically. This report describes the clinical findings in a patient who had likely been in a ventricular tachyarrhythmia for several days and presented in ventricular fibrillation, ambulatory, and mentating normally. This report, with previous similar reports, is additive to the body of evidence that LVADs alter the physiologic impact of ventricular arrhythmias in advanced heart failure and highlights the need for thoughtful programming of implantable cardioverter defibrillator therapies in these patients.

Surgical treatment of tricuspid valve insufficiency promotes early reverse remodeling in patients with axial-flow left ventricular assist devices.

OBJECTIVE: The HeartMate II (Thoratec Corp, Pleasanton, Calif) continuous-flow left ventricular assist device has emerged as the standard of care for patients with advanced heart failure. The objective of this study was to assess the safety and early effectiveness of concomitant tricuspid valve procedures in patients undergoing implantation of a HeartMate II device. METHODS: From February 2007 to April 2010, 83 patients underwent HeartMate II left ventricular assist device implantation. Of these, 37 patients had concomitant tricuspid valve procedures (32 repairs, 5 replacements) for severe tricuspid regurgitation. The effects of a tricuspid valve procedure on tricuspid regurgitation and right ventricular remodeling were assessed comparing echocardiographic findings at baseline and 30 days after left ventricular assist device implantation. Overall survival was also compared. RESULTS: Patients undergoing a concomitant tricuspid valve procedure had more tricuspid regurgitation (vena contracta, 5.6 ± 2.1 mm vs 2.9 ± 2.0 mm; P < .001), worse right ventricular dysfunction (right ventricular end-diastolic area, 33.6 ± 6.2 mm vs 31.6 ± 8.5 mm; P = .05), higher mean right atrial pressure (17.4 ± 7.1 mm Hg vs 14.9 ± 5.1 mm Hg; P = .03), and a higher Kormos score (2.6 ± 2.1 vs 1.2 ± 1.4; P = .0008) preoperatively. One month after surgery, tricuspid regurgitation was worse in patients who underwent left ventricular assist device implantation alone (+18.6%), whereas it improved significantly in patients undergoing a concomitant tricuspid valve procedure (-50.2%) (P = .005). A corresponding significant reduction in right ventricular end-diastolic area (33.6% ± 6.2% vs 30.1% ± 9.7%; P = .03) and a trend toward better right ventricular function (55.5% ± 79.7% vs 35.7% ± 60.5%; P = .28) were noted in patients undergoing a concomitant tricuspid valve procedure. Survival was comparable between the 2 groups. CONCLUSIONS: In patients with severe tricuspid regurgitation undergoing left ventricular assist device implantation, a concomitant tricuspid valve procedure effectively reduces tricuspid regurgitation and promotes reverse remodeling of the right ventricle.

Application of Computer Modeling in Systemic VAD Support of Failing Fontan Physiology.

Although the Fontan procedure has been enormously successful in palliation of single-ventricle patients, many seem to experience progressive failure of the Fontan circulation over time. Ventricular assist devices (VADs) have developed into stable platforms for long-term support of adult patients with heart failure. Given the success of axial flow devices, it was hypothesized that the technology could provide clinical benefit to failing Fontan patients. The aim of this study was to use a computer model to evaluate VAD support in failing Fontan physiology. A computer model of Fontan circulation with heart failure was developed and the HeartMate II (HM II) (Thoratec Corp) axial flow ventricular assist device was connected to this model in a systemic configuration to examine its impact. Cardiac catheterization data from 7 patients (8 catheterization studies) with failing Fontan physiology were applied to this model to evaluate the impact of using the HM II in this manner. When the HM II was used in a systemic configuration at 8000 rpm, there was a 35% decrease in the systemic venous pressure in the Fontan circuit and a 63% decrease in pulmonary capillary wedge pressure with a resultant 41% increase in CI. The model also predicted patient-specific parameters where the VAD may not benefit the patient, such as fixed elevated pulmonary vascular resistance, low systemic ventricular end-diastolic pressure, and high unresponsive systemic vascular resistance. These data suggest a potential benefit from application of axial flow VAD technology in the management of failing Fontan physiology. Clinical correlation will allow for refinement of this model as a predictive tool in discerning which patients may benefit from placement of a VAD and what issues must be addressed prior to implanting the device.

Successful lung transplant from donor after cardiac death: a potential solution to shortage of thoracic organs.

Lung transplant is an effective treatment for patients with end-stage lung disease but is limited because of the shortage of acceptable donor organs. Organ donation after cardiac death is one possible solution to the organ shortage because it could expand the pool of potential donors beyond brain-dead and living donors. We report the preliminary experience of Mayo Clinic with donation after cardiac death, lung procurement, and transplant.

Mitral annular growth in children following early mechanical mitral valve replacement.

Irreparable mitral pathology may lead to early mitral valve replacement (MVR) in children. Often, a small mechanical prosthesis (<23 mm) is required, raising concerns about annular growth in patients who may eventually require subsequent mitral valve re-replacement (MVRR). The aim of this study was to evaluate interval mitral annular growth in this cohort. Between January 1972 and December 2006, 164 children underwent MVR with a mechanical prosthesis; 110 of these children (median age, 4 years; range, 7 days to 14 years) received a small mechanical prosthesis (<23 mm). The most common diagnoses were congenital mitral stenosis (10%), regurgitation (46%), and left atrioventricular valve dysfunction after previous atrioventricular septal defect repair (44%). The cohort was analyzed for age, body surface area (BSA), prosthesis size, and Z score at the time of MVR and MVRR. At the time of MVR, 78 patients had a BSA of 0.77 ± 0.06 m(2), had an annular size of 24 ± 0.62 mm (Z score, 2.91 ± 0.23), and ultimately did not require MVRR. Another cohort, who eventually did require MVRR (n = 24), had an initial BSA at the time of MVR of 0.62 ± 0.05 m(2) (P = NS vs MVR only) and an annular size of 20 ± 0.49 mm (Z score, 1.85 ± 0.22) (P = .008 vs MVR only). In the interval between MVR and MVRR (7.8 ± 1.1 years), BSA increased to 1.12 ± 0.07 m(2), and annulus size increased to 24 ± 0.47 mm (Z score, 1.80 ± 0.28). These data suggest growth of the mitral annulus following MVR with a small mechanical prosthesis, as evidenced by an unchanged Z score in the setting of normal interval increase in BSA. Additionally, there was a statistically significant difference in initial Z scores between the cohorts requiring MVRR and those who have not needed re-replacement, suggesting that the feasibility of placement of a slightly larger prosthesis may be associated with a decreased need for MVRR.