Mustafa Cikirikcioglu

Mitral Valve Repair for Rheumatic Valve Disease in Children: Midterm Results and Impact of the Use of a Biodegradable Mitral Ring

BACKGROUND Mitral valve repair for rheumatic mitral valve disease in children has become the preferred surgical modality. A mitral valve ring is frequently used in the repair. A recently introduced biodegradable ring has shown promising results and allows for growth of the native annulus. METHODS Between January 1994 and March 2006, 220 children underwent mitral valve repair for rheumatic valve disease. Mitral valve insufficiency was predominant in 198 patients (90%). Fifty-seven patients (26%) had associated aortic valve insufficiency and 51 (23%) had tricuspid valve insufficiency addressed during the same surgery. A mitral valve ring was used in 213 patients (173 Carpentier-Edwards and 40 biodegradable rings). Ninety-two percent (202 of 220) were in New York Association class III to IV. Echocardiography was performed at 6 months and thereafter once yearly. RESULTS There were no hospital deaths or major postoperative morbidity. Follow-up was complete in 96% (212 of 220). One late death occurred. Mean follow-up was 76.4 months (range, 1 to 13 years). One patient (0.5%) had immediate mitral valve repair failure and required mitral valve replacement. Twelve patients (5.5%) required reoperation during follow-up. Recurrent mitral valve insufficiency/stenosis-free survival was 94.5% at 5 years and 92.7% at 10 years. Mean gradient was 5.2 +/- 1.9, 6.2 +/- 2.0, and 7.0 +/- 2.3 mm Hg, respectively, at 7 days, 6 months, and 1 year postoperatively for the Carpentier-Edwards ring and significantly lower (p < 0.001) for the biodegradable ring at 2.8 +/- 0.5, 3.1 +/- 0.7, and 3.3 +/- 0.5 mm Hg, respectively. Unchanged mean gradient during the first year was 65% (26 of 40) for the biodegradable ring and 21% (31 of 147) for the Carpentier-Edwards ring. CONCLUSIONS Mitral valve repair in children with rheumatic valve disease has excellent immediate results with low operative risk and satisfactory midterm results and should therefore be the preferred treatment of choice. The use of biodegradable mitral valve ring results in a significant lower mean gradient during the first year of implantation compared with the Carpentier-Edwards ring and is available in a wide range of sizes.

Porcine carotid artery replacement with biodegradable electrospun poly-e-caprolactone vascular prosthesis

OBJECTIVE There is a continuous search for shelf-ready small-caliber vascular prostheses with satisfactory early and late results. Biodegradable scaffolds, repopulated by recipients cells regenerating a neovessel, can be a suitable option for adult and pediatric, urgent and elective cardiovascular procedures. METHODS This was a short-term experimental assessment of a new biodegradable vascular prosthesis for arterial replacement in the pig. Eleven pigs underwent bilateral carotid artery replacement with biodegradable electrospun poly-ε-caprolactone (PCL) nanofiber prostheses (internal diameter, 4 mm; length, 5 cm); or expanded polytetrafluoroethylene (ePTFE) prostheses as control. Perioperative anticoagulation was achieved with intravenous heparin (double baseline activated clotting time). Postoperatively, until conclusion of the study at 1 month, animals received aspirin and clopidogrel daily. Transit time flow was measured intraoperatively and at sacrifice. Doppler ultrasound (1 and 4 weeks) and a selective carotid angiography (4 weeks) were performed to assess patency. All explanted grafts were analyzed by histology, morphometry, and scanning electron microscopy in order to study graft-host interaction. RESULTS Surgical handling and hemostasis of the new prostheses were excellent. Patency rate was 78% (7/9) for PCL grafts, compared with 67% (4/6) for ePTFE grafts. Transit time flow and Doppler ultrasound showed no significant changes in flow and velocity or diameter over time in both groups. Both prostheses showed no detectable in vivo compliance as compared with native carotid artery. Percent neoendothelialization was 86% for PCL and 58% for ePTFE grafts (P = .008). Neointima formation was equal in both grafts. More adventitial infiltration of macrophages, myofibroblasts, and capillaries was seen in PCL grafts with a milder foreign-body reaction when compared with ePTFE implants. Both grafts showed similar endoluminal thrombus formation. CONCLUSIONS Biodegradable, electrospun PCL grafts showed good surgical and mechanical properties, no aneurysm formation, and similar short-term patency compared with ePTFE grafts. Rapid endothelialization and cell ingrowth confirms favorable PCL graft-recipient biological interaction. Despite good early results, long-term follow-up is required before clinical application.

The effects of modified hemofiltration on inflammatory mediators and cardiac performance in coronary artery bypass grafting

Cardiopulmonary bypass increases the blood levels of various immune mediators, thereby leading to a systemic inflammatory response syndrome, e.g. sepsis, with some hemodynamic alterations, such as vasodilatation, tachycardia, and a decrease in systemic vascular resistance. Perioperative hemofiltration is one of the treatment modalities proposed to prevent this syndrome. Modified hemofiltration has been introduced recently by investigators who recommend that the former standard techniques are ineffective in eliminating the inflammatory mediators. The purpose of this study was to determine the effects of the modified technique on these mediators and on hemodynamic parameters. Forty patients undergoing coronary artery bypass grafting were randomized into equal control and hemofiltered groups. The hemodynamic parameters, as well as blood samples, were taken before and after hemofiltration to assess blood concentrations of interleukin-6, interleukin-8 and neopterin. The hemodynamic parameters and immune mediator levels did not differ between the two groups during the course of the study, except in the immediate postoperative periods, where cardiac output, cardiac index, and systemic vascular resistance values were significantly greater in the hemofiltered group while there were no differences in the immune mediators. The results of our study suggest that the effects of modified hemofiltration on immune mediators are still debatable. The improvement found in cardiac performance could be attributed to the prevention of hemodilution and hypervolemia.

Aortic valve repair by cusp extension for rheumatic aortic insufficiency in children: Long-term results and impact of extension material

OBJECTIVE Aortic valve repair has encouraging midterm results in selected patients. However, neither the long-term results of cusp extension nor the durability of different pericardial fixation techniques has been reported. Our goal was to address these issues. METHODS Seventy-eight children with severe rheumatic aortic regurgitation (mean age 12 ± 3.5 years) underwent aortic valve repair using cusp extension over a 15-year period, with fresh autologous pericardium in 53 (67.9%), glutaraldehyde-fixed bovine pericardium in 9 (11.5%), and PhotoFix bovine pericardium (Sorin CarboMedics, Milano, Italy) in 16 (20.5%). Fifty-seven children (73.1%) underwent concomitant mitral valve repair, and 8 children (10.3%) underwent tricuspid valve repair. RESULTS There was 1 operative death from left ventricular failure. During a median follow-up of 10.7 years (range 1 month to 16.4 years), 1 late death occurred and 15 patients (19.7%) required reoperation at a mean of 43 ± 33.7 months (range 1 month to 9 years), 9 within the autologous pericardium group (18%), 3 within the bovine pericardium group (33%), and 3 within the PhotoFix pericardium group (19%). Freedom from reoperation was 96% ± 2.3% at 1 year, 87.5% ± 3.9% at 5 years, 80.7% ± 4.9% at 10 years, and 75.3% ± 6% at 15 years, and was significantly decreased in the bovine pericardium group (P = .039). On multivariable analysis, greater age (hazard ratio 1.25, P < .001) and acute rheumatic carditis (hazard ratio 8.15, P = .001) at operation were significant predictors of reoperation. CONCLUSIONS Aortic cusp extension provides adequate valve repair in a large proportion of children with rheumatic aortic regurgitation. Fresh autologous and PhotoFix pericardium trended toward better durability than glutaraldehyde-fixed bovine pericardium.

Total endovascular aortic arch reconstruction via fenestration in situ with cerebral circulatory support: an acute experimental study

The aim of this experimental study is to evaluate the feasibility of endovascular repair of the complete aortic arch by using novel fenestration devices with simultaneous support of the cerebral circulation. Two fresh human cadavers and five Yorkshire pigs were used for the experiments. In human cadavers the thoracic aorta was pressurized using a roller pump to simulate the circulation. In animal experiments right femoral artery to right distal carotid artery bypass circuit was achieved in order to support the cerebral circulation during the stent graft deployment, fenestration and conduit fixation procedures. Commercially available Valiant Thoracic Stent Grafts, covered stents, steerable guiding catheters and dilatation balloons were used. Stent grafts were deployed successfully and two fenestrations and one conduit implantation were achieved in each cadaver. All animals survived the stent graft implantation, fenestration and conduit implantation procedures. Cadaver dissection and necropsy of the animals revealed good fixation of the conduits into the fenestrated segments of the stent graft. Endovascular repair of the total aortic arch via in situ fenestration of the stent graft using cerebral circulatory support seems to be feasible and safe. Further studies are required before clinical adoption of this procedure.

Transcatheter aortic valve implantation in nonagenarians: Effective and safe

BACKGROUND The number of nonagenarians is rising dramatically. These patients often develop severe aortic stenosis for which transcatheter aortic valve implantation (TAVI) is an attractive option. The aim of this study was to analyze the outcome of TAVI performed in a cohort of nonagenarian patients. METHODS Between August 2008 and November 2012, 23 consecutive patients in their 90th year of age or older underwent TAVI in our institution after having been assessed by the local heart team. Data concerning baseline characteristics, procedural details and outcome were prospectively entered into a dedicated database. Transthoracic echocardiography and clinical follow-up were performed pre-procedure, at discharge, at 6 and 12 months and then annually post TAVI. RESULTS Patients were male in 52% with a mean age of 90.3 ± 2.3 years. Mean logistic EuroSCORE and STS score were 26.6 ± 14.5% and 8.7 ± 2.9%, respectively. Transcatheter heart valve (THV) could be implanted in all but one patient. Mortality at 30 days was 8.7% overall and 4.8% for transfemoral approach. At 30 days the rate of stroke was 4.3%, paravalvular leak grade ≥ 2 was 8.7%, life-threatening bleeding was 13.0% and pacemaker implantation was 13%. Device success was 73.9%. The rate of all-cause mortality increased to 27.3% at one-year follow-up and 42.8% at a median follow-up of 417 days. CONCLUSIONS TAVI is safe and effective even in a selected population of nonagenarians. Consequently, these patients should not be refused such a procedure based only on their age. Multi-disciplinary assessment is essential in order to properly select candidates.

Midterm results of valve repair with a biodegradable annuloplasty ring for acute endocarditis.

BACKGROUND Conventional annuloplasty rings consist of woven, nondegradable prosthetic material. Their use should theoretically be limited in acute infective endocarditis. Novel biodegradable annuloplasty rings, which are implanted into the annulus, carry theoretical advantages, but have never been evaluated for feasibility and mid-term outcome in such patients. METHODS Between 2004 and 2009, 17 consecutive patients with acute infective endocarditis (age, 34.5+/-21.6 years; range, 11-82 years; 8 men) had mitral (n=13), tricuspid (n=3), and mitral and tricuspid (n=1) annuloplasty to conclude valve repair. Repair was performed by complete excision of the infected tissue, valvar reconstruction, and biodegradable ring annuloplasty. Prospectively collected clinical and echocardiographic data were analyzed retrospectively. RESULTS Indications for surgery were heart failure (n=9; 52.9%), hemodynamic instability (n=8; 47%), and persistent infection or sepsis despite antibiotics (n=6; 35.3%). Staphylococci (n=7) and Streptococci (n=4) were the most common causes. Three patients died on postoperative days 1, 2, and 34 because of massive gastrointestinal bleeding; heart failure and pneumonia; and sepsis and acute renal failure, respectively. During a median follow-up of survivors at 29.6 months (range, 2.0 to 51.0 months), no mortality, recurrence, or reoperation occurred. At follow-up, transthoracic echocardiography revealed no or trivial regurgitation in 11 and mild in 3 patients. Left ventricular dimensions regressed significantly after mitral repair. CONCLUSIONS Valve repair using a biodegradable ring showed good structural and functional properties up to 4 years after repair. Implantation of the biodegradable ring is feasible and effective in patients with acute infective endocarditis. Its intraannular implantation, hindering direct blood contact and associated risk of colonization, represents a theoretical advantage in such patients. Larger comparative studies are needed for further conclusions.

Papillary fibroelastoma of the left atrial wall: a case report

Cardiac papillary fibroelastoma is a rare, benign cardiac tumor. It often arises from valvular endocardium, and non-valvular endocardial location is rare. Although transthoracic echocardiography is usually sufficient for the diagnosis of most cardiac tumors, small tumors such as papillary fibroelastoma may be missed. Transesophageal echocardiography is superior to transthoracic echocardiography in diagnosing these tumors. Despite their benign histology, and independent of their size, they should be resected surgically because of their high potential for embolization.In this report, we present a case of papillary fibroelastoma located on the left atrial wall, presenting with symptoms of cerebral ischemia. The patient was treated surgically for the prevention of further embolic complications. Pertinent literature is also reviewed for this rare and benign cardiac tumor.

Preoperative diastolic function predicts the onset of left ventricular dysfunction following aortic valve replacement in high-risk patients with aortic stenosis

IntroductionLeft ventricular (LV) dysfunction frequently occurs after cardiac surgery, requiring inotropic treatment and/or mechanical circulatory support. In this study, we aimed to identify clinical, surgical and echocardiographic factors that are associated with LV dysfunction during weaning from cardiopulmonary bypass (CPB) in high-risk patients undergoing valve replacement for aortic stenosis.MethodsPerioperative data were prospectively collected in 108 surgical candidates with an expected operative mortality ≥9%. All anesthetic and surgical techniques were standardized. Reduced LV systolic function was defined by an ejection fraction <40%. Diastolic function of the LV was assessed using standard Doppler-derived parameters, tissue Doppler Imaging (TDI) and transmitral flow propagation velocity (Vp).ResultsDoppler-derived pulmonary flow indices and TDI could not be obtained in 14 patients. In the remaining 94 patients, poor systolic LV was documented in 14% (n = 12) and diastolic dysfunction in 84% of patients (n = 89), all of whom had Vp <50 cm/s. During weaning from CPB, 38 patients (40%) required inotropic and/or mechanical circulatory support. By multivariate regression analysis, we identified three independent predictors of LV systolic dysfunction: age (Odds ratio [OR] = 1.11; 95% confidence interval (CI), 1.01 to 1.22), aortic clamping time (OR = 1.04; 95% CI, 1.00 to 1.08) and Vp (OR = 0.65; 95% CI, 0.52 to 0.81). Among echocardiographic measurements, Vp was found to be superior in terms of prognostic value and reliability. The best cut-off value for Vp to predict LV dysfunction was 40 cm/s (sensitivity of 72% and specificity 94%). Patients who experienced LV dysfunction presented higher in-hospital mortality (18.4% vs. 3.6% in patients without LV dysfunction, P = 0.044) and an increased incidence of serious cardiac events (81.6 vs. 28.6%, P < 0.001).ConclusionsThis study provides the first evidence that, besides advanced age and prolonged myocardial ischemic time, LV diastolic dysfunction characterized by Vp ≤ 40 cm/sec identifies patients who will require cardiovascular support following valve replacement for aortic stenosis.

No-Patch Technique for Complete Atrioventricular Canal Repair

Although no-patch repair was the first surgical treatment for complete atrioventricular canal, patch repairs are currently more widely used. We assessed the safety of forgoing a patch during the correction of complete atrioventricular canal in 8 consecutive patients. The complete atrioventricular canal was repaired using sutures placed on the right of the ventricular septal defect crest, passed through the bridging leaflet, and to the facing part of the ostium primum defect. There were no early deaths; all patients were in sinus rhythm without left ventricular outflow tract obstruction. This no-patch technique produces results comparable with the modified single-patch repair, while reducing ischemic time.