Matthias Roth

Tissue-Engineered Cardiac Constructs for Cardiac Repair

Several recent basic research studies have described surgical methods for cardiac repair using tissue cardiomyoplasty. This review summarizes recent advances in cardiac repair using bioengineered tissue from the viewpoint of the cardiac surgeon. We conclude that the results of many basic and preclinical studies indicate that bioengineered tissue can be adapted to conventional surgical techniques. However, no clinical studies have yet proved bioengineered tissue is effective as a treatment for human heart failure. Todays cardiac surgeons can look forward to the advent of new techniques to benefit patients who respond poorly to existing treatment for heart failure.

Do patients want minimally invasive aortic valve replacement

OBJECTIVE Access to aortic valve can be performed through small incisions. However, a considerable advantage of this approach has not been proven by randomized studies so far. We wanted to elucidate the opinion of patients when they are informed objectively about advantages and disadvantages of minimally invasive approach prior to operation. METHODS This prospective study was performed with 27 patients undergoing isolated aortic valve replacement. These patients were informed prior to operation by the same resident concerning objective data. A photograph was shown illustrating a patient with postoperative wound after a standard- and a mini-incision, respectively. After the interview the patient could decide between full and partial sternotomy. RESULTS After the interview 21/27 (78%) patients preferred to have a full sternotomy (group F) and 6/27 (22%) patients (group P) decided to have a partial sternotomy. Comments of group F: surgeon should have best exposure (n=15); cosmetics aspects unimportant (n=14); operation time as short as possible (n=7). Group P: cosmetic aspects important (n=6). Significant differences between groups (group F vs. group P): age (years), 69.1+/-1.5 vs. 49.2+/-7.3 (P=0.024); operation time (min), 142+/-7 vs. 189+/-15 (P=0.002); CK (IU/l), 111+/-11 vs. 374+/-114 (P=0.0007); CKMB (IU/l), 17+/-2 vs. 45+/-17 (P=0.006); ICU-stay (days), 2.6+/-0.2 vs. 3.2+/-0.2 (P=0.044). Pericardial effusion requiring drainage was observed in two patients of group P. One patient of group P suffered myocardial infarction. CONCLUSION When patients are informed objectively about advantages and disadvantages of minimal invasive aortic valve surgery only a smaller number decides to have a mini incision. The patients preferring short incisions are significantly younger since cosmetic aspects are more important. Longer duration of operation may be due to longer hemostasis based on limited exposure. Air bubbles due to inadequate de-airing might be responsible for higher CK and CK-MB levels in group P.

Three-year hemodynamic performance, left ventricular mass regression, and prosthetic-patient mismatch after rapid deployment aortic valve replacement in 287 patients

OBJECTIVE Superior aortic valve hemodynamic performance can accelerate left ventricular mass regression and enhance survival and functional status after surgical aortic valve replacement. This can be achieved by rapid deployment aortic valve replacement using a subannular balloon-expandable stent frame, which functionally widens and reshapes the left ventricular outflow tract, to ensure a larger effective orifice area compared with conventional surgical valves. We report the intermediate-term follow-up data from a large series of patients enrolled in the Surgical Treatment of Aortic Stenosis With a Next Generation Surgical Aortic Valve (TRITON) trial. METHODS In a prospective, multicenter (6 European hospitals), single-arm study, 287 patients with aortic stenosis underwent rapid deployment aortic valve replacement using a stented trileaflet bovine pericardial bioprosthesis. Core laboratory echocardiography was performed at baseline, discharge, and 3 months, 1 year, and 3 years after rapid deployment aortic valve replacement. RESULTS The mean patient age was 75.7 ± 6.7 years (range, 45-93; 49.1% women). The mean aortic valve gradient significantly decreased from discharge to 3 years of follow-up. The mean effective orifice area remained stable from discharge to 3 years. At 1 year, the left ventricular mass index had decreased by 14% (P < .0001) and at 3 years by 16% (P < .0001) compared with at discharge. The prevalence of severe patient-prosthesis mismatch was 3% at discharge and remained stable during the follow-up period. CONCLUSIONS In a large series of elderly patients with symptomatic severe aortic stenosis, rapid deployment aortic valve replacement using a subannular balloon-expandable stent frame demonstrated excellent hemodynamic performance and significant left ventricular mass regression. With continued follow-up, future studies will establish whether these favorable structural changes correlate with improvement in long-term survival and functional status.

Cardioscopy: potential applications and benefit in cardiac surgery

OBJECTIVE Cardioscopy in open heart surgery is still not routine in most units. However, since our first report in 1996 we use this device more frequently, because we think that safety and accuracy of different surgical procedures is increased. METHODS Between 1/96 and 12/97 we performed cardioscopy in 100 patients. Indications (IND) for cardioscopy were as follows: IND (1) resection of hypertrophied septum (N = 15); IND (2) evaluation of aortic valve with low grade stenosis or insufficiency (N = 12); IND (3) removal of intracardiac foreign bodies/tumors (N = 13); IND (4) inspection of VSD prior and after repair (N = 8); IND (5) identification of paravalvular leakage (N = 8); IND (6) diagnostic purposes (N = 4); IND (7) education of surgeons and operating room staff (N = 40). During cardioplegic arrest the 5 mm rigid or flexible cardioscope (Storz, Tuttlingen, Germany) was inserted through ascending aorta, aortic valve or tricuspid valve depending on indication. RESULTS No complication occurred during cardioscopy. IND (1): there was an excellent view of all intracardiac structures. Thorough resection of hypertrophied septum was possible and there was no injury of adjacent structures or aortic valve. IND (2): all valves were inspected through a 1 cm aortic incision and the pathology of the valves was documented. In case of severe calcification, the valve was replaced although transvalvular gradient was less than 50 mm Hg. IND (3): intraventricular foreign bodies, such as felt pledges (N = 2), debris (N = 5), thrombi (N = 4) and tumors (N = 2) were entirely removed through the aortic valve with a special forceps. IND (4): anatomy of VSD was documented in all cases. It was possible to test accuracy of all patch-sutures. IND (5): all paravalvular leakages were identified even though there was heavy immobility of the mechanical valve. IND (6): a papillary muscle (N = 2) and a thrombus formation (N = 2) were diagnosed. IND (7): the surgeons and operating room staff could follow the entire procedure in all cases. CONCLUSIONS Cardioscopy is a supporting technique to clearly identify intracardiac structures, to control several surgical procedures, to document valve pathology, and to educate surgeons and operating room staff. Handling is easy and does not increase operative risk. Some procedures will be performed with minimal invasivity in future.

Post-mitral valve repair systolic anterior motion produced by non-obstructive septal bulge

OBJECTIVE Systolic anterior motion (SAM) may rarely occur after mitral valve reconstruction due to different anatomic factors. Several techniques have been described to reduce the incidence of post-repair SAM, e.g. leaflet sliding plasty. However, SAM can still occur after these special procedures. We reviewed data of patients developing SAM with significant mitral regurgitation due to non-obstructive septal bulge. METHODS During a 2-year period mitral valve repair was performed in 358 patients. Five of 358 (1.4%) patients with a mean age of 52+/-10.5 years developed post-repair SAM with severe mitral insufficiency due to non-obstructive septal bulge. Data of these patients were analyzed retrospectively and controlled after a mean follow-up of 18+/-2.7 months. RESULTS Preoperative echocardiography showed end-diastolic septum diameter of 7, 10, 10, 11 and 15 mm. The ratio between end-diastolic septum diameter and free wall diameter was 1 in four patients and 1.25 in one patient. There was no left ventricular outflow tract obstruction (LVOT). Intraoperative data revealed large myxomatous anterior (four patients) and posterior (three patients) leaflets. Quadrangular resection of posterior leaflet was carried out in four patients and sliding plasty in one patient. Cause for post-repair mitral regurgitation was a non-obstructive septal bulge. During a second pump run septal bulge was resected. Mean aortic cross-clamp time and cardiopulmonary bypass time for this procedure was 15+/-1.4 and 28+/-3.1 min, respectively. Mitral regurgitation disappeared in all patients immediately after this procedure. The grade of mitral regurgitation at follow-up was 0-1 in all patients. One patient had subaortic gradient of 36 mmHg. CONCLUSIONS If mitral regurgitation occurs after primary successful mitral repair, septum bulge should always be considered as the primary cause for SAM even there is no preoperative gradient in LVOT. Before performing time-consuming corrective operations to relieve SAM, a septum resection should be carried out during a short second pump run.

Ruptured papillary muscle after mitral valve replacement with preservation of chordae tendineae

Many cardiac surgeons believe strongly that every effort should be made to preserve the continuity of the mitral anulus, chordae tendineae, and papillary muscles during mitral valve replacement in order to maximize ventricular function and maintain normal ventricular geometry. We treated a patient with spontaneous papillary muscle rupture after mitral valve replacement in whom efforts had been made to preserve continuity of the mitral mechanism.

Video-Assisted Resection of Hypertrophied and Fibrous Intraventricular Tissue

There is increasing interest in endoscopic techniques in cardiac surgery. However, use of the endoscope during open heart operations is still not routine. Cardioscopy has been used in patients with hypertrophied obstructive cardiomyopathy, asymmetric septal hypertrophy, or membranous subaortic stenosis. We demonstrate the resection of this pathologic tissue under direct visualization. With this technique we could increase the safety and accuracy of this surgical procedure. Beside this advantage, the entire operating room staff could follow the surgical intervention, which increases its educational side-effect.

Repair of an aneurysm of the pulmonary trunk in a 65-year-old patient

The case of a 65-year-old patient with asymptomaticaneurysm of the pulmonary trunk associated with severe insufficiency of the pulmonary valve and symptomatic coronary artery disease is presented. The surgical procedure included coronary artery bypass grafting, aneurysmectomy, and pulmonary artery replacement with implantation of a stentless bioprosthesis and lengthening of the root of the bioprosthesis with a reversed vascular Y prosthesis, which was anastomosed to the left and right pulmonary artery.

Long-term outcomes of a rapid deployment aortic valve: data up to 5 years†

OBJECTIVES Rapid deployment aortic valve replacement (AVR) has been developed to facilitate minimally invasive approaches for cardiac surgery and shorten procedural times. TRITON is a prospectively designed study to assess safety and efficacy of rapid deployment AVR with Edwards INTUITY valve system. This report presents the 5-year outcomes of the TRITON trial. METHODS A total of 295 patients with aortic valve stenosis were enrolled in the TRITON trial and 287 patients received the study valve. Procedural, early (≤30 days) and late (>30 days) outcomes were collected. Valve haemodynamic performance was evaluated at specified time points by an independent Echocardiography Core Laboratory and clinical events adjudicated by an independent Clinical Events Committee. RESULTS Mean age was 75.3 ± 6.7 years. A total of 158 patients underwent isolated AVR and 129 patients underwent AVR with concomitant procedures. The 5-year survival rates were 85.7 ± 3.4% and 75.2 ± 4.9% for isolated AVR and concomitant AVR, respectively. Overall, freedom from valve-related death at 5 years was 98.2 ± 0.8%. At 5 years, the valve effective orifice area was 1.6 ± 0.3 cm 2 , mean gradient was 10.5 ± 5.4 mmHg and peak gradient was 18.9 ± 9.3 mmHg. CONCLUSIONS The 5-year outcomes of the TRITON trial demonstrate acceptable long-term safety and excellent haemodynamic performance of rapid deployment AVR with the Edwards INTUITY valve system. ClinicalTrials.gov NCT01445171.

Aneurysm Formation After Patch Aortoplasty Repair (Vossschulte): Reoperation in Adults With and Without Hypothermic Circulatory Arrest

BACKGROUND Aortic aneurysm formation is common after patch aortoplasty repair of coarctation of the aorta. Its incidence varies between 5% and 38%. The majority of patients show progressive aneurysmal dilation within 6 to 18 years and reoperation is necessary to avoid rupture of the aneurysm. METHODS Ten patients were reoperated on for patch aneurysm formation. Femorofemoral cardiopulmonary bypass (CPB) with a heparinized system was used in all patients. Decision to initiate hypothermic circulatory arrest (HCA) was made intraoperatively. All patients received a Dacron graft replacement of the aneurysmatic thoracic aorta. RESULTS HCA was initiated in 5 patients owing to extreme adhesions in vicinity to the aneurysm. There was no significant intergroup difference regarding time interval after first operation, age, operation time, and postoperative blood loss. Only minor neurologic events were present in 2 patients with cross-clamping the aorta. CONCLUSIONS Patch aneurysms after Vossschulte aortoplasty can safely be operated on with femorofemoral CPB. Initiation of HCA is recommended to prevent rupture of the aneurysm during preparation and injury of adjacent nerves and vessels.