Successful valve-in-valve transcatheter intervention to treat severe stenosis of a 38-year-old tricuspid bioprosthesis.

A 60-year-old man presented with breathlessness. Nearly four decades previously, he had required three operations for Staphylococcus aureus infective endocarditis of the tricuspid valve and had received a bioprosthetic valve. He had critical tricuspid bioprosthesis stenosis which was treated successfully by valve-in-valve transcatheter tricuspid valve replacement using a balloon-expandable transcatheter heart valve. One year after intervention, the patient is well with no tricuspid valve stenosis or regurgitation.

Thrombocytopenia after sutureless and standard stented aortic valve replacement: a retrospective analysis of risk factors, clinical course, and early outcome.

OBJECTIVES: Thrombocytopenia following Perceval aortic valve replacement has been described previously with variable outcome. Studies have lacked a robust analysis of platelet fluctuation and factors affecting it. We aimed to statistically describe the trend in thrombocyte variability as compared with conventional aortic valve replacement, and to assess predictors as well as impact on associated outcomes. METHODS: One hundred consecutive patients with first-time Perceval were retrospectively compared to 219 patients after Perimount Magna Ease valve replacement. The primary outcome was the serial thrombocyte count on day 0-6. Generalized estimating equations were used to analyse the data using fixed-effect models: for the effect of the post-operative day on platelet count, and random-effect models estimating both time-variant (platelets) and time in-variant variables (valve type, age, LV function, pre-op platelet level). RESULTS: Perceval patients were older (72 ± 1 vs 68 ± 1 years, p < 0.01) with higher NYHA status (3(2-3) vs 2(1-2), p < 0.001). Mean platelet count in the sutureless group was lowest on day 2 (91.9 ± 31.6 vs 121.7 ± 53.8 × 103 µl-1), and lower on day 4 (97.9 ± 44) and 6 (110.6 ± 61) compared to the conventional group (157.2 ± 60 and 181.7 ± 79) but did not result in a higher number of transfusions, bleeding or longer hospital stay (p > 0.05). Reduced platelet count was a strong predictor of red cell transfusion in the conventional (p = 0.016), but not in the sutureless group (p = 0.457). Age (Coef -1.025, 95%CI-1.649--0.401, p < 0.001) and CPB-time (Coef 0.186, 95%CI-0.371--0.001, p = 0.048) were predictors for lower platelet levels. CONCLUSION: Considering the older patient profile treated with Perceval, postoperative thrombocytopenia does not impact on outcome in terms of transfusions, complications or hospital stay.

Devastating fungal endocarditis involving ascending aorta in a patient with a history of aortic valve replacement: a case report.

BACKGROUND: Fungal endocarditis is a rare but serious condition associated with high mortality rates. Various predisposing factors contribute to its occurrence, such as underlying cardiac abnormalities, cardiac surgeries, prosthetic cardiac devices, and central venous catheters. Diagnosing fungal endocarditis, particularly Aspergillus, poses challenges, often complicated by negative blood cultures. CASE PRESENTATION: This report details a case of extensive ascending aorta involvement in Aspergillus endocarditis (AE) in a 24-year-old man with a history of bioprosthesis aortic valve replacement (AVR). Three months post-AVR, he presented with pericardial effusion and aortic rupture, leading to a redo biological valved conduit aortic root replacement (Bentall surgery). Despite the intervention, the tubular graft exhibited extensive Aspergillus involvement, resulting in graft disruption and significant peri-aortic infection. A second redo procedure involving aortic homograft root replacement was performed. Unfortunately, the patient succumbed two days after the surgery. CONCLUSION: A combined approach of medical and surgical therapies is recommended to manage fungal endocarditis. Despite efforts, the mortality rate associated with Aspergillus endocarditis remains unacceptably high, with no significant difference observed between combination therapy and antifungal treatment alone. Further research is essential to explore novel therapeutic strategies and improve outcomes for patients with this challenging condition.

[Sudden Chest Pain due to Early Bioprosthetic Valve Dysfunction:Report of a Case].

We report a case of bioprosthetic valve dysfunction and acute aortic valve regurgitation. The case was a 75-year-old female who had sudden onset chest pain. ST-segment depression in several leads on electrocardiogram( ECG) suggested acute coronary syndrome. Coronary angiography showed no significant stenosis in coronary arteries. Transesophageal echocardiography revealed severe aortic regurgitation, suggesting that angina was caused by myocardial ischemia associated with acute aortic regurgitation. She was diagnosed as having bioprosthetic valve dysfunction, and underwent redo aortic valve replacement. One leaflet of the bioprosthetic valve was torn along the stent post and caused bioprosthetic valve dysfunction. Failed bioprosthetic valve was removed and replaced by a mechanical valve.

Unusual cause of severe transvalvular eccentric jet AR: early structure valve deterioration of Trifecta valves by flail leaflet undergoing valve-in-valve transcatheter aortic valve replacement.

The Trifecta tissue valve (Abbott, Illinois, USA) is an externally mounted bovine pericardial aortic valve (AV) prosthesis with adequate haemodynamic performance and better early results than another option. However, concerns have been raised about its durability. Recently, reports have emerged about an increased incidence of early structural valve failure after Trifecta implantation, where leaflet tear(s) with dehiscence along the stent post was the primary mode of early failure. In this article, we present the case of a patient in her 70s, 7 years after AV replacement with a Trifecta valve, who developed progressive dyspnoea. Physical examination revealed signs of chronic severe aortic regurgitation (AR). The initial transthoracic echocardiogram showed severe transvalvular AR, but the aetiology could not be determined. Cardiac computed tomography (CT) revealed a flail non-coronary cusp of the Trifecta bioprosthetic valve without vegetation. After discussion, we concluded that our patient was suitable for valve-in-valve transcatheter aortic valve replacement (ViV TAVR).

Impact of explanted valve type on aortic valve reoperations: nationwide UK experience.

OBJECTIVES: This nationwide retrospective cohort study assessed the impact of the explanted valve type on reoperative outcomes in aortic valve surgery within the UK over a 23-year period. METHODS: Data were sourced from the National Institute for Cardiovascular Outcomes Research (NICOR) database. All patients undergoing first-time isolated reoperative aortic valve replacement between 1996 and 2019 in the UK were included. Concomitant procedures, homograft implantation or aortic root enlargement were excluded. Propensity score matching was utilized to compare outcomes and risk factors for in-hospital mortality was evaluated through multivariable logistic regression. Final model selection was conducted using Akaike Information Criterion through bootstrapping. The primary end point was in-hospital mortality, and secondary end points included postoperative morbidities. RESULTS: Out of 2371 patients, 24.9% had mechanical and 75% had bioprosthetic valves implanted during the primary procedure. Propensity matched groups of 324 patients each, were compared. In-hospital mortality for mechanical and bioprosthetic valve explants was 7.1% and 5.9%, respectively (P = 0.632). On multivariable logistic regression analysis, valve type was not a risk factor for mortality [odds ratio (OR) 0.62, 95% confidence interval (CI) 0.37-1.05; P = 0.1]. Age (OR 1.03, 95% CI 1.01-1.05; P < 0.05), left ventricular ejection fraction (OR 1.62, 95% CI 1.08-2.42; P < 0.05), creatinine ≥ 200 mg/dl (OR 2.21, 95% CI 1.17-4.04; P < 0.05) and endocarditis (OR 2.66, 95% CI 1.71-4.14; P < 0.05) emerged as risk factors for mortality. CONCLUSIONS: The type of valve initially implanted (mechanical or bioprosthetic) did not determine mortality. Instead, age, left ventricular ejection fraction, renal impairment and endocarditis were significant risk factors for in-hospital mortality.

Perceval sutureless bioprosthesis versus Perimount sutured bioprosthesis for aortic valve replacement in patients with aortic stenosis: a retrospective, propensity-matched study.

BACKGROUND: Rapid-deployment aortic valve replacement (RDAVR) is an alternative to conventional AVR (cAVR) for aortic stenosis. Benefits include a reduction in operative times, facilitation of minimal access surgery and superior haemodynamics compared to conventional valves. However, further evidence is required to inform guidelines, preferably in the form of propensity-matched studies that include mid-term follow-up data. METHODS: This was a single-centre, retrospective, propensity-matched cohort study comparing the Perceval and conventional Perimount Magna Ease valve for short- and mid-term clinical parameters and size-matched mid-term echocardiographic parameters (n = 102 in both groups) from 2014 to 2020. Data were extracted from a nationally managed dataset. RESULTS: There were no demographic differences between the matched groups. The Perceval group had shorter cross-clamp time (Perceval 62 [49-81] minutes; Perimount 79 [63-102] minutes, P < 0.001), shorter bypass time (Perceval 89 [74-114] minutes; Perimount 104 [84-137] minutes, P < 0.001), and more frequent minimally-invasive approaches (Perceval 28%; Perimount 5%, P < 0.001). Size-matched haemodynamics showed initially higher gradients in the Perceval group, but haemodynamics equalised at 12 + months. The Perceval group had a more favourable % change in the left ventricular posterior wall dimension at 2 + years (Perceval - 4.8 ± 18; Perimount 17 ± 2). CONCLUSIONS: The Perceval facilitated shorter operations, which may benefit intermediate-high-risk, elderly patients with comorbidities requiring concomitant procedures. It also facilitated minimally invasive surgery. Size-matched haemodynamic performance was similar at mid-term follow-up, with the Perceval possibly better facilitating regression of left ventricular hypertrophy.

Early and mid-term outcomes after aortic valve replacement using a novel tissue bioprosthesis: a systematic review.

OBJECTIVES: While current data show a clear trend towards the use of bioprosthetic valves during aortic valve replacement (AVR), durability of bioprosthetic valves remains the most important concern. We conducted a 1st systematic review of all available evidence that analysed early and mid-term outcomes after AVR using the Inspiris RESILIA™ bioprosthesis. METHODS: A systematic literature search was performed to identify all relevant studies evaluating early and mid-term outcomes after AVR using the Inspiris RESILIA bioprosthesis and including at least 20 patients with no restriction on the publication date. Subgroup meta-analysis was performed to compare Inspiris RESILIA and PERIMOUNT Magna Ease bioprosthesis and to pool the early postoperative mortality and stroke rates. RESULTS: A total of 416 studies were identified, of which 15 studies met the eligibility criteria. The studies included a total of 3202 patients with an average follow-up of up to 5.3 years. The average age of patients across the studies was 52.2-75.1 years. Isolated AVR was performed in 39.0-86.4% of patients. In-hospital or 30-day postoperative mortality was 0-2.8%. At the mid-term follow-up, freedom from all-cause mortality was up to 85.4%. Among studies with mid-term follow-up, trace/mild paravalvular leak was detected in 0-3.0%, while major paravalvular leak was found only in up to 2.0% of patients. No statistically significant differences in terms of mortality (P = 0.98, odds ratio 1.02, 95% confidence interval 0.36-2.83) and stroke (P = 0.98, odds ratio 1.01, 95% confidence interval 0.38-2.73) between the Inspiris RESILIA bioprosthesis and PERIMOUNT Magna Ease bioprosthesis were observed in the subgroup meta-analysis. CONCLUSIONS: Mid-term data on the safety and haemodynamic performance of the novel aortic bioprosthesis are encouraging. Further comparative studies with other bioprostheses and longer follow-up are still required to endorse durability and safety of the novel bioprosthesis.

Outcomes of Valve-in-Valve Transcatheter Aortic Valve Replacement.

Structural valve degeneration is increasingly seen given the higher rates of bioprosthetic heart valve use for surgical and transcatheter aortic valve replacement (TAVR). Valve-in-valve TAVR (VIV-TAVR) is an attractive alternate for patients who are otherwise at high risk for reoperative surgery. We compared patients who underwent VIV-TAVR and native valve TAVR through a retrospective analysis of our institutional transcatheter valve therapy (TVT) database from 2013 to 2022. Patients who underwent either a native valve TAVR or VIV-TAVR were included. VIV-TAVR was defined as TAVR in patients who underwent a previous surgical aortic valve replacement. Kaplan-Meier survival analysis was used to obtain survival estimates. A Cox proportional hazards regression model was used for the multivariable analysis of mortality. A total of 3,532 patients underwent TAVR, of whom 198 (5.6%) underwent VIV-TAVR. Patients in the VIV-TAVR cohort were younger than patients who underwent native valve TAVR (79.5 vs 84 years, p <0.001), with comparable number of women and a higher Society of Thoracic Surgeons risk score (6.28 vs 4.46, p <0.001). The VIV-TAVR cohort had a higher incidence of major vascular complications (2.5% vs 0.8%, p = 0.008) but lower incidence of permanent pacemaker placement (2.5% vs 8.1%, p = 0.004). The incidence of stroke was comparable between the groups (VIV-TAVR 2.5% vs native TAVR 2.4%, p = 0.911). The 30-day readmission rates (VIV-TAVR 7.1% vs native TAVR 9%, p = 0.348), as well as in-hospital (VIV-TAVR 2% vs native TAVR 1.4%, p = 0.46), and overall (VIV-TAVR 26.3% vs native TAVR 30.8%, p = 0.18) mortality at a follow-up of 1.8 years (0.83 to 3.5) were comparable between the groups. The survival estimates were also comparable between the groups (log-rank p = 0.27). On multivariable Cox regression analysis, VIV-TAVR was associated with decreased hazards of death (hazard ratio 0.68 [0.5 to 0.9], p = 0.02). In conclusion, VIV-TAVR is a feasible and safe strategy for high-risk patients with bioprosthetic valve failure. There may be potentially higher short-term morbidity with VIV-TAVR, with no overt impact on survival.

Iatrogenic bioprosthetic, self-expandable, transcatheter aortic valve replacement dysfunction after cardiac catheterization.

Bioprosthetic valve dysfunction (BVD) is typically a progressive process related to natural wear of the prosthesis. With acute presentations, possible durability issues or iatrogenic causes need to be considered. Here, we present 2 patients with acute BVD of self-expanding, transcatheter aortic valve replacement post-heart catheterization. The presentations and outcomes, in otherwise normally functioning valves antecedent to the heart catheterizations, raise the question of the increased complexity of coronary access in this valve platform, and whether that or other features provide for greater risk of such events. We believe this to be the first publication of such events and they help to highlight the importance of valve implantation planning, as well as familiarity with the potential complexity of coronary access during heart catheterization.

Bioprosthetic versus mechanical valves for mitral valve replacement in patients < 70 years: an updated pairwise meta-analysis.

BACKGROUND: The ideal conduit for mitral valve replacement (MVR) remains elusive, particularly among younger patients due to increased life expectancy. We perform a pairwise meta-analysis comparing the use of bioprosthetic valves (BPV) and mechanical mitral valves (MMV) in patients < 70 years old undergoing MVR. METHODS: We comprehensively searched medical databases to identify studies comparing the use of BPV and MMV in patients < 70 years old undergoing MVR. Pairwise meta-analysis was performed using the Mantel-Haenszel method in R version 4.0.2. Outcomes were pooled using the random effect model as risk ratios (RR) with their 95% confidence intervals (95% CI). RESULTS: 16,879 patients from 15 studies were pooled. Compared to MMV, BPV was associated with significantly higher rates of 30-day mortality (RR 1.53, p = 0.0006) but no difference in 30-day stroke (RR 0.70, p = 0.43). At a weighted mean follow-up duration of 14.1 years, BPV was associated with higher rates of long-term mortality (RR 1.28, p = 0.0054). No difference was seen between the two groups for risk of long-term stroke (RR 0.92, p = 0.67), reoperation(RR 1.72, p = 0.12), or major-bleeding (RR 0.57, p = 0.10) at a weighted mean follow-up duration of 11.7, 11.3, and 11.9 years, respectively. CONCLUSION: The use of MMV in patients < 70 undergoing MVR is associated with lower rates of 30-day/long-term mortality compared to BPV. No significant differences were observed for risk of 30-day/long-term stroke, long-term reoperation, and long-term major bleeding. These findings support the use of MMV in younger patients, although prospective, randomized trials are still needed.

Role of lipoprotein(a) concentrations in bioprosthetic aortic valve degeneration.

OBJECTIVES: Lipoprotein(a) (Lp(a)) is associated with an increased incidence of native aortic stenosis, which shares similar pathological mechanisms with bioprosthetic aortic valve (bAV) degeneration. However, evidence regarding the role of Lp(a) concentrations in bAV degeneration is lacking. This study aims to evaluate the association between Lp(a) concentrations and bAV degeneration. METHODS: In this retrospective multicentre study, patients who underwent a bAV replacement between 1 January 2010 and 31 December 2020 and had a Lp(a) measurement were included. Echocardiography follow-up was performed to determine the presence of bioprosthetic valve degeneration, which was defined as an increase >10 mm Hg in mean gradient from baseline with concomitant decrease in effective orifice area and Doppler Velocity Index, or new moderate/severe prosthetic regurgitation. Levels of Lp(a) were compared between patients with and without degeneration and Cox regression analysis was performed to investigate the association between Lp(a) levels and bioprosthetic valve degeneration. RESULTS: In total, 210 cases were included (mean age 74.1±9.4 years, 72.4% males). Median time between baseline and follow-up echocardiography was 4.4 (IQR 3.7) years. Bioprostheses degeneration was observed in 33 (15.7%) patients at follow-up. Median serum levels of Lp(a) were significantly higher in patients affected by degeneration versus non-affected cases: 50.0 (IQR 72.0) vs 15.6 (IQR 48.6) mg/dL, p=0.002. In the regression analysis, high Lp(a) levels (≥30 mg/dL) were associated with degeneration both in a univariable analysis (HR 3.6, 95% CI 1.7 to 7.6, p=0.001) and multivariable analysis adjusted by other risk factors for bioprostheses degeneration (HR 4.4, 95% CI 1.9 to 10.4, p=0.001). CONCLUSIONS: High serum Lp(a) is associated with bAV degeneration. Prospective studies are needed to confirm these findings and to investigate whether lowering Lp(a) levels could slow bioprostheses degradation.

Revisiting aortic valve prosthesis choice in patients younger than 50 years: 10 years results of the AUTHEARTVISIT study.

OBJECTIVES: This population-based cohort study investigated mid-term outcome after surgical aortic valve replacement with a bioprosthetic or mechanical valve prosthesis in patients aged <50 years in a European social welfare state. METHODS: We analysed patient data from the main social insurance carriers in Austria (2010-2020). Subsequent patient-level record linkage with national health data provided patient characteristics and clinical outcome. Survival, reoperation, myocardial infarction, heart failure, embolic stroke or intracerebral haemorrhage, bleeding other than intracerebral haemorrhage and major adverse cardiac events were evaluated as outcomes. RESULTS: A total of 991 patients were analysed. Regarding demographics, no major differences between groups were observed. Multivariable Cox regression revealed no significant difference in overall survival (P = 0.352) with a median follow-up time of 6.2 years. Reoperation-free survival was decreased (hazard ratio = 1.560 [95% CI: 1.076-2.262], P = 0.019) and the risk for reoperation was increased (hazard ratio = 2.770 [95% CI: 1.402-5.472], P = 0.003) in patients who received bioprostheses. Estimated probability of death after reoperation was 0.23 (CL: 0.08-0.35) after 2 years and 0.34 (CL: 0.06-0.53) after 10 years over both groups. Regarding further outcomes, no significant differences between the two groups were observed. CONCLUSIONS: In patients below 50 years of age receiving aortic valve replacement, implantation of bioprostheses when compared to mechanical heart valve prostheses was associated with a significantly higher rate of reoperations and reduced reoperation-free survival. Nevertheless, we could not observe a difference in overall survival. However, long-term follow-up has to evaluate that a significantly lower rate of reoperations may translate in consistently improved long-term survival.

Degenerated Transcatheter Aortic Valve Replacement: Investigation and Management Options.

With the expansion of transcatheter aortic valve replacement (TAVR) to younger and lower-surgical-risk patients, many younger and less comorbid patients will be treated with TAVR and are expected to have a life expectancy that will exceed the durability of their transcatheter heart valve. Consequently, the number of patients requiring reintervention will undoubtedly increase in the near future. Redo-TAVR and TAVR explantation followed by surgical aortic valve replacement are the different therapeutic options in the event of bioprosthetic valve failure and the need for reintervention. Patients often anticipate being able to benefit from a redo-TAVR in the event of bioprosthetic valve failure after TAVR, despite the lack of long-term data and the risk of unfavourable anatomy. Our understanding of the feasibility of redo-TAVR is constantly improving thanks to bench test studies and growing worldwide experience. However, much remains unknown. In clinical practice, one of the heart team's objectives is to anticipate the need to reaccess the coronary arteries and implant a second or even a third valve when life expectancy may exceed the durability of the transcatheter heart valve. In this review, we address key definitions in the diagnosis of structural valve deterioration and bioprosthetic valve failure, as well as patient selection and procedural planning for redo-TAVR to reduce periprocedural risk, optimise hemodynamic performance, and maintain coronary access. We describe the bench testing and literature in the redo-TAVR and TAVR explantation fields.

Prosthetic Valve Endocarditis After Aortic Valve Replacement With Bovine Versus Porcine Bioprostheses.

BACKGROUND: Whether a bovine or porcine aortic valve bioprosthesis carries a higher risk of endocarditis after aortic valve replacement is unknown. The aim of this study was to compare the risk of prosthetic endocarditis in patients undergoing aortic valve replacement with a bovine versus porcine bioprosthesis. METHODS AND RESULTS: This nationwide, population-based cohort study included all patients who underwent surgical aortic valve replacement with a bovine or porcine bioprosthesis in Sweden from 1997 to 2018. Regression standardization was used to account for intergroup differences. The primary outcome was prosthetic valve endocarditis, and the secondary outcomes were all-cause mortality and early prosthetic valve endocarditis. During a maximum follow-up time of 22 years, we included 21 022 patients, 16 603 with a bovine valve prosthesis and 4419 with a porcine valve prosthesis. The mean age was 73 years, and 61% of the patients were men. In total, 910 patients were hospitalized for infective endocarditis: 690 (4.2%) in the bovine group and 220 (5.0%) in the porcine group. The adjusted cumulative incidence of prosthetic valve endocarditis at 15 years was 9.5% (95% CI, 6.2%-14.4%) in the bovine group and 2.8% (95% CI, 1.4%-5.6%) in the porcine group. The absolute risk difference between the groups at 15 years was 6.7% (95% CI, 0.8%-12.5%). CONCLUSIONS: The risk of endocarditis was higher in patients who received a bovine compared with a porcine valve prosthesis after surgical aortic valve replacement. This association should be considered in patients undergoing both surgical and transcatheter aortic valve replacement.

Root-commando operation with a modified self-assembled aortic root conduit for endocarditis after sutureless aortic valve replacement.

We present a case of a Staphylococcus epidermidis early prosthetic valve endocarditis after minimally invasive sutureless aortic valve replacement. The patient developed a root abscess with a fistula, severe mitral and periprosthetic regurgitations, with a large mitral vegetation and a residual patent foramen ovale. The surgical approach consisted of a redo median sternotomy, explantation of a sutureless aortic prosthesis, resection of an intervalvular fibrosa and anterior mitral leaflet and debridement of an aortic root-left ventricle outflow tract abscess. These procedures were followed by a root-commando procedure with mitral and aortic root placement using a self-assembled mechanical aortic root conduit. The technique used is an alternative to a root-commando procedure performed with an allograft or a Medtronic Freestyle bioprosthesis. The same technique can be utilized with a commercially available stented bioprosthesis.

Endothelial Microparticles: Markers of Inflammatory Response After Sutureless Valve Implantation.

INTRODUCTION: Systemic inflammatory response syndrome (SIRS) is related to increased circulating endothelial microparticles (EMP). OBJECTIVE: The aim of this study was to compare the plasma concentration of EMP between patients undergoing aortic valve replacement with conventional bioprosthesis implantation and Perceval™ S (LivaNova) and to evaluate its impact on the inflammatory response in the short-term follow-up. METHODS: This is a randomized clinical trial with 24 patients submitted to isolated aortic valve replacement divided into two groups: Perceval™ S (Group P) and conventional bioprostheses (Group C). Incidence of severe SIRS (three or more criteria) in the first 48 hours postoperatively, EMP release profile, interleukins (IL) 6 and 8, C-reactive protein, and procalcitonin were analyzed preand postoperatively at 24 hours and three months. RESULTS: There were 24 patients (12 in each group), mean age was 69.92±5.17 years, 83.33% were female, the incidence of severe SIRS was 66.7% and 50% in groups C and P, respectively (P=0.68), and EMP showed a significant increase in the 24-hour postoperative period (P≤0.001) and subsequent decrease in the three-month postoperative period (P≤0.001), returning to baseline levels. For IL-6 and IL-8, there was a greater increase in group C at 24 hours postoperatively (P=.0.02 and P<0.001). CONCLUSION: The incidence of severe SIRS was similar in both groups, with significantly higher levels of IL-6 and IL-8, at the 24-hour postoperative period, in group C, however with higher levels of EMP in group P, and subsequent return to baseline levels at the three-month postoperative period in both groups.