Peter Oberwalder

Cardiac myxomas: 24 years of experience in 49 patients

OBJECTIVES In this single-center study we reviewed our experience with a significant number of cardiac myxoma cases occurring over the past two decades. PATIENTS AND METHODS Cardiac myxomas represented 86% of all surgically treated cardiac tumors at our center. Specifically, there were 49 consecutive patients, each with at least one myxoma. A detailed clinical, immunological, and echocardiographic long-term examination of 37 patients revealed one recurrent myxoma. RESULTS Most myxomas originated from the left atrium (87.7%), but also much less frequently from the mitral valve (6.1%), from the right atrium (4.1%), and from the left and right atria (2.0%). The myxomas produced a prolapse into the left ventricle in 40.8% of the patients, mitral stenosis in 10.2%, and threatened left ventricular outflow tract obstruction in 2.0%. Multiple myxomas were found in 20.4% of the patients. Cardiac signs appeared in 93.9% of the patients. Preoperative embolic events had occurred in 26.5%. Immunologic alterations were present in 87.5%. For resection, a bilateral atriotomy was used. An additional aortotomy was needed to expose one mitral valve myxoma. Postoperatively, 81.1% of the patients remained without cardiac symptoms. The early mortality rate was 2.0% and the late mortality rate was 6.1%. Long-term prognosis was excellent with an actuarial survival rate of 0.74. Specific immunologic alterations were found in 71.4% of the patients. The actuarial freedom from reoperation of the myxoma was 0.96. The rate of reoperations was low with 2.0% after 24 years. CONCLUSIONS Myxomas were usually detected and operated on in symptomatic patients. A high index of suspicion seems important for early diagnosis. Immunologic findings may play an additional role in confirming the diagnosis and the recurrence of a myxoma. Immediate surgical treatment was indicated because of the high risk of embolization or of sudden cardiac death. Also, a familial genesis must be excluded in myxoma patients.

Sutureless aortic valve replacement: a systematic review and meta-analysis.

BACKGROUND Sutureless aortic valve replacement (SU-AVR) has emerged as an innovative alternative for treatment of aortic stenosis. By avoiding the placement of sutures, this approach aims to reduce cross-clamp and cardiopulmonary bypass (CPB) duration and thereby improve surgical outcomes and facilitate a minimally invasive approach suitable for higher risk patients. The present systematic review and meta-analysis aims to assess the safety and efficacy of SU-AVR approach in the current literature. METHODS Electronic searches were performed using six databases from their inception to January 2014. Relevant studies utilizing sutureless valves for aortic valve implantation were identified. Data were extracted and analyzed according to predefined clinical endpoints. RESULTS Twelve studies were identified for inclusion of qualitative and quantitative analyses, all of which were observational reports. The minimally invasive approach was used in 40.4% of included patients, while 22.8% underwent concomitant coronary bypass surgery. Pooled cross-clamp and CPB duration for isolated AVR was 56.7 and 46.5 minutes, respectively. Pooled 30-day and 1-year mortality rates were 2.1% and 4.9%, respectively, while the incidences of strokes (1.5%), valve degenerations (0.4%) and paravalvular leaks (PVL) (3.0%) were acceptable. CONCLUSIONS The evaluation of current observational evidence suggests that sutureless aortic valve implantation is a safe procedure associated with shorter cross-clamp and CPB duration, and comparable complication rates to the conventional approach in the short-term.

Late dissection of the ascending aorta after previous cardiac surgery: risk, presentation and outcome.

OBJECTIVE Aortic dissection is a potentially life-threatening condition and may follow surgical interventions as a complication with distinct presentation and high mortality. Information on the incidence and etiology of aortic dissections following cardiac surgery is sparse and inconsistent. The true incidence of this entity may so far have been underestimated. METHODS Data of 223 operations on the thoracic aorta performed exclusively at our institution between January 1990 and May 2001 were analysed for clinical and prognostic features. Patients with Marfan syndrome and traumatic cases were not included. Cases of type A aortic dissection following cardiac surgery were investigated further. RESULTS Dissection of the ascending aorta occurred in 83 patients, of whom 11 (13.2%, six acute and five chronic) had undergone previous cardiac surgery (four aortic valve replacements (AVR), two double valve replacements (DVR), two AVR+coronary artery bypass grafts (CABG), three CABGs). The time interval between first operation and dissection was 0.2-17 years (median 3.3 years). Eight (72%) patients had arterial hypertension. The aortic diameter was >or=50mm in all 11 cases upon presentation. Dissections were treated with Bentall procedures (3), Cabrol procedure (1), supracoronary tube graft (6) including concomitant CABG (3) and AVR with local repair (1). Total in-hospital mortality was 54% (6/11), and 66% (4/6) in cases with acute dissection due to low cardiac output (3) and myocardial infarction (3). CONCLUSIONS Type-A aortic dissection can follow cardiac operations at any time with no typical interval or associated histology and with high overall hospital mortality. Male patients with arterial hypertension are at increased risk. Clinical presentation may differ from primary dissection with implications for management and risk estimation.

Treatment of Acute Aortic Type B Dissection with Stent-Grafts

AbstractPurpose: To evaluate the feasibility of endoluminal stent-grafts in the treatment of acute type B aortic dissections. Methods: In five patients with acute aortic type B dissections, sealing of the primary intimal tear with an endoluminal stent-graft was attempted. Indication for treatment was aneurysm formation in two patients and persistent pain in three patients. One of the latter also had an unstable dissection flap compromising the ostium of the superior mesenteric artery. The distance from the intimal tear to the left subclavian artery was <0.5 cm in four patients, who had typical type B dissections. In one patient with an atypical dissection the distance from the primary tear to the left subclavian artery was 4 cm. This patient had no re-entry tear. Talent tube grafts (World Medical Manufacturing Cooperation, Sunrise, FL, USA) were used in all patients. Results: Stent-graft insertion with sealing of the primary tear was successful in all patients. The proximal covered portion of the stent-graft was placed across the left subclavian artery in four patients (1× transposition of the left subclavian artery). Left arm perfusion was preserved via a subclavian steal phenomenon in the patients in whom the stent-graft covered the orifice of the left subclavian artery. The only procedural complication we observed was an asymptomatic segmental renal infarction in one patient. In the thoracic aorta thrombosis of the false aortic lumen occurred in all patients. In one patient the false lumen of the abdominal aorta thrombosed after 4 weeks; in the other three patients the status of the abdominal aorta remained unchanged compared with the situation prior to stent-graft insertion. As a late complication formation of a secondary aneurysm of the thoracic aorta was observed at the distal end of the stent-graft 3 months after the primary intervention. This aneurysm was treated by coaxial insertion of an additional stent-graft without complications. Conclusion: Endoluminal treatment of acute type B aortic dissections seems to be an attractive alternative treatment to surgical repair. Thrombosis of the false lumen of the thoracic aorta can be induced if the primary tear is sealed with a stent-graft. This could protect the dissected thoracic aorta from delayed rupture.

Sutureless, rapid deployment valves and stented bioprosthesis in aortic valve replacement: recommendations of an International Expert Consensus Panel.

OBJECTIVES After a panel process, recommendations on the use of sutureless and rapid deployment valves in aortic valve replacement were given with special respect as an alternative to stented valves. METHODS Thirty-one international experts in both sutureless, rapid deployment valves and stented bioprostheses constituted the panel. After a thorough literature review, evidence-based recommendations were rated in a three-step modified Delphi approach by the experts. RESULTS Literature research could identify 67 clinical trials, 4 guidelines and 10 systematic reviews for detailed text analysis to obtain a total of 28 recommendations. After rating by the experts, 12 recommendations were identified and degree of consensus for each was determined. Proctoring and education are necessary for the introduction of sutureless valves on an institutional basis as well as for the individual training of surgeons. Sutureless and rapid deployment should be considered as the valve prosthesis of first choice for isolated procedures in patients with comorbidities, old age, delicate aortic wall conditions such as calcified root, porcelain aorta or prior implantation of aortic homograft and stentless valves as well as for concomitant procedures and small aortic roots to reduce cross-clamp time. Intraoperative transoesophageal echocardiography is highly recommended, and in case of right anterior thoracotomy, preoperative computer tomography is strongly recommended. Suitable annular sizes are 19-27 mm. There is a contraindication for bicuspid valves only for Type 0 and for annular abscess or destruction due to infective endocarditis. Careful but complete decalcification of the aortic root is recommended to avoid paravalvular leakage; extensive decalcification should be avoided not to create annular defects. Proximal anastomoses of concomitant coronary artery bypass grafting should be placed during a single aortic cross-clamp period or alternatively with careful side clamping. Available evidence suggests that the use of sutureless and rapid deployment valve is associated with (can translate into) reduced early complications such as prolonged ventilation, blood transfusion, atrial fibrillation, pleural effusions and renal replacement therapy, respectively, and may result in reduced intensive care unit and hospital stay in comparison with traditional valves. CONCLUSION The international experts recommend various benefits of sutureless and rapid deployment technology, which may represent a helpful tool in aortic valve replacement for patients requiring a biological valve. However, further evidence will be needed to reaffirm the benefit of sutureless and rapid deployment valves.

Left ventricular outflow tract obstruction due to valve myxoma

A life-threatening left ventricular outflow tract obstruction developed in a 26-year-old man because of a very uncommon myxoma emerging from the ventricular side of the mitral valve. Immediate surgical treatment was indicated because of high-risk factors reported herein. After transaortic resection of a single myxoma, the progress of this patient has been excellent, especially as a familial myxoma could be excluded.

Endovascular Treatment of Mycotic Aortic Pseudoaneurysms with Stent-Grafts

Mycotic aortic aneurysms remain a therapeutic challenge, especially in patients who are not suitable for open surgery. Endovascular treatment with stent-grafts in this indication is still disputed. Between January 2002 and January 2006, six patients with mycotic aneurysms of the thoracoabdominal or abdominal aorta were admitted to our department. All patients were male, aged 57–83 years (mean, 74.6 years). The mycotic aneurysms were diagnosed on the basis of clinical signs of infection, on CT, and, in four cases, on a positive blood culture. In all patients the mycotic aortic aneurysms were treated endovascularly by stent-graft implantation. Technical and clinical success was achieved in all patients. There was no in-hospital or 30-day mortality. In the follow-up period (range, 2–47 months) four patients died of cancer, cardiac failure, or unknown cause (one case). Two patients are still alive with nearly complete regression of the aneurysms. We conclude that treatment of mycotic aortic aneurysms with stent-grafts may be an alternative in selected patients.

Type-A Aortic Dissection after Non-Aortic Cardiac Surgery

Background— Cardiac surgery with cardiopulmonary bypass is associated with mechanical manipulation of the ascending aorta that occasionally leads to type A aortic dissection (AAD). Methods and Results— One hundred three patients with surgical repair for AAD following nonaortic cardiac surgery were identified. With the use of logistic regression modeling, coronary artery bypass surgery (CABG), either isolated or combined with another procedure in the initial operation, was associated with significantly higher operative mortality in comparison with patients with non-CABG procedures at the time of AAD repair both for all patients (odds ratio, 2.90; 95% confidence interval, 1.09–7.72; P=0.033) and for patients with acute and chronic AAD ≥30 days after the initial operation (odds ratio, 3.62; 95% confidence interval, 1.13–11.54; P=0.03). In patients who developed AAD late after the initial operation, operative mortality was highest in patients without preoperative coronary angiography and appropriate management of their native coronary artery disease and graft disease (odds ratio, 5.36; 95% confidence interval, 1.68–17.0; P=0.002). Nearly all the intimal dissection tears were located at sites of previous surgical trauma. Most of the ascending aortas that had dissected initially had a diameter ≥40 mm with histological evidence of medial degeneration in resected tissue samples. Conclusions— In patients who have undergone previous cardiac surgery, preexisting aortic wall pathology contributes to AAD with typical intimal damage at sites of mechanical trauma. The operative mortality was the highest in patients with previous CABG in comparison with patients with non-CABG procedures. Preoperative coronary angiography and operative management of native coronary and graft disease were significantly associated with outcome in patients with previous CABG.

Type A Aortic Dissection After Nonaortic Cardiac Surgery

Background— Cardiac surgery with cardiopulmonary bypass is associated with mechanical manipulation of the ascending aorta that occasionally leads to type A aortic dissection (AAD). Methods and Results— One hundred three patients with surgical repair for AAD following nonaortic cardiac surgery were identified. With the use of logistic regression modeling, coronary artery bypass surgery (CABG), either isolated or combined with another procedure in the initial operation, was associated with significantly higher operative mortality in comparison with patients with non-CABG procedures at the time of AAD repair both for all patients (odds ratio, 2.90; 95% confidence interval, 1.09–7.72; P=0.033) and for patients with acute and chronic AAD ≥30 days after the initial operation (odds ratio, 3.62; 95% confidence interval, 1.13–11.54; P=0.03). In patients who developed AAD late after the initial operation, operative mortality was highest in patients without preoperative coronary angiography and appropriate management of their native coronary artery disease and graft disease (odds ratio, 5.36; 95% confidence interval, 1.68–17.0; P=0.002). Nearly all the intimal dissection tears were located at sites of previous surgical trauma. Most of the ascending aortas that had dissected initially had a diameter ≥40 mm with histological evidence of medial degeneration in resected tissue samples. Conclusions— In patients who have undergone previous cardiac surgery, preexisting aortic wall pathology contributes to AAD with typical intimal damage at sites of mechanical trauma. The operative mortality was the highest in patients with previous CABG in comparison with patients with non-CABG procedures. Preoperative coronary angiography and operative management of native coronary and graft disease were significantly associated with outcome in patients with previous CABG.

Sutureless Aortic Valve Replacement International Registry (SU-AVR-IR): design and rationale from the International Valvular Surgery Study Group (IVSSG)

BACKGROUND Sutureless aortic valve replacement (SU-AVR) is an innovative approach which shortens cardiopulmonary bypass and cross-clamp durations and may facilitate minimally invasive approach. Evidence outlining its safety, efficacy, hemodynamic profile and potential complications is replete with small-volume observational studies and few comparative publications. METHODS Minimally invasive aortic valve surgery and high-volume SU-AVR replacement centers were contacted for recruitment into a global collaborative coalition dedicated to sutureless valve research. A Research Steering Committee was formulated to direct research and support the mission of providing registry evidence warranted for SU-AVR. RESULTS The International Valvular Surgery Study Group (IVSSG) was formed under the auspices of the Research Steering Committee, comprised of 36 expert valvular surgeons from 27 major centers across the globe. IVSSG Sutureless Projects currently proceeding include the Retrospective and Prospective Phases of the SU-AVR International Registry (SU-AVR-IR). CONCLUSIONS The global pooling of data by the IVSSG Sutureless Projects will provide required robust clinical evidence on the safety, efficacy and hemodynamic outcomes of SU-AVR.