Friedrich-Christian Riess

Coronary Hybrid Revascularization from January 1997 to January 2001: A Clinical Follow-Up

BACKGROUND Hybrid revascularization (HyR), combining minimally invasive left internal mammary artery (LIMA) bypass grafting to the left anterior descending coronary artery (LAD) and catheter interventional treatment of the remaining coronary lesions, avoids the disadvantages associated with cardiopulmonary bypass (CPB). We investigated the clinical follow-up of 57 patients with multivessel disease undergoing this procedure in the last 4 years. METHODS Between January 1997 and January 2001, 57 consecutive patients (41 men and 16 women, aged 65.7 +/- 7.9 years) with coronary artery disease (two-vessel, n = 34; three-vessel, n = 23) were treated with off-pump LIMA-to-LAD bypass combined with balloon angioplasty and stenting of the remaining significantly obstructed (> 50%) coronary vessels. Clinical follow-up data included a early postoperative and a 6-month control angiography and a patient interview in January 2001. RESULTS All patients underwent LIMA-to-LAD bypass-grafting and balloon angioplasty in 72 coronary lesions without procedural-related complications. However, one early LIMA bypass occlusion was documented during coronary angiography. Postoperatively no deterioration of preexistent organ dysfunction was observed in any patient. The mean follow-up was 100.7 +/- 37.9 weeks in 55 of 57 patients (97%). Control angiography 6 months after HyR (n = 34) revealed a patent LIMA bypass in 33 patients and 8 in-stent restenoses (> 50%) in the coronary arteries that were treated interventionally by re-PTCA (n = 6) or by conventional CABG (n = 1). In 1 patient medical treatment resulted in significant reduction of angina so no further intervention was considered necessary. After HyR 1 patient died 18 months later of an intracerebral hemorrhage. All other patients are alive and doing well. CONCLUSIONS Our results indicate that in selected patients with multivessel disease including left main stem stenosis HyR is an effective and secure procedure with excellent early and good midterm results. Especially elderly patients with severe concomitant diseases appear to benefit from this approach by avoiding CPB.

A case report on the use of recombinant hirudin as an anticoagulant for cardiopulmonary bypass in open heart surgery

We present a patient with coronary heart disease and a heparin- induced thrombocytopenia , who was successfully treated by coronary ar- tery bypass grafting (CABG) using recombinant hirudin as an anticoagu- lant for cardiopulmonary bypass (CPB) instead of heparin. (Eur J Car- dio-thorac Surg (1996) 10: 386-388)

Beating Heart Operations Including Hybrid Revascularization: Initial Experiences

BACKGROUND The outcome of patients (n = 45) with coronary one- to three-vessel disease undergoing beating heart operations using a recently developed stabilizing device was investigated. METHODS Left internal mammary artery-to-left anterior descending coronary artery (LIMA-to-LAD) revascularization was carried out alone (n = 31) or as hybrid procedure in combination with a balloon angioplasty (n = 14). RESULTS All 45 patients underwent a successful LIMA-to-LAD procedure without intraoperative complication during a 21 +/- 8-minute (range, 10 to 53 minutes) LAD occlusion time. In 14 hybrid procedures a total of 19 stenoses including 3 left main stenoses were treated successfully by percutaneous transluminal coronary angioplasty and stenting. The postoperative courses were uneventful with the exception of two surgical reexplorations necessitated by bleeding. No worsening of renal, neurologic, or respiratory functions occurred in any patient. In the group having a single LIMA-to-LAD procedure, early postoperative coronary angiograms (22 of 31) showed a patent LIMA graft and excellent anastomosis; this was also true in 4 patients 12 months after operation as shown in angiograms. All patients undergoing hybrid revascularization demonstrated a patent LIMA-to-LAD anastomosis; in 1 patient there was a dissection in the midlevel of the LIMA, which was stented successfully. The 6-month follow-up angiograms in 7 of 14 patients revealed open LIMA bypass grafts in all patients except 1, who was stented because of dissection. CONCLUSIONS These data indicate that a beating heart operation including hybrid revascularization is safe and effective in selected patients with coronary one- to three-vessel disease including left main stenosis. This approach may be especially advantageous in comparison with conventional coronary artery bypass grafting in patients with severe concomitant disease.

Medtronic Mosaic porcine bioprosthesis: Assessment of 12-year performance

BACKGROUND The Mosaic porcine bioprosthesis (Medtronic, Inc, Minneapolis, Minn) was approved in 2000 by the US Food and Drug Administration. Clinical performance was evaluated in 6 centers. METHODS From 1994 to 2000, 797 patients (mean age 69 years) had aortic valve replacement (AVR) and 232 (mean 67 years) had mitral valve replacement (MVR). Concomitant coronary artery bypass grafting was performed with aortic valve replacement (45.4%) and mitral valve replacement (43.5%). Mean follow-ups were 7.5 years for aortic position and 7.3 years for mitral position. RESULTS Early mortalities were 2.8% for AVR and 3.0% for MVR. Late mortalities were 4.2%/patient-year for AVR and 5.1%/patient-year for MVR. Overall 12-year survivals were 55.8% ± 3.7% for AVR and 43.9% ± 7.4% for MVR. Twelve-year freedoms from valve-related mortality were 87.1% ± 3.1% for AVR and 82.5% ± 7.7% for MVR. Twelve-year freedoms from reoperation were 84.0% ± 3.3% for AVR and 82.5% ± 7.5% for MVR. Freedoms from structural valve deterioration (SVD) by explant reoperation at 12 years for AVR were 93.3% ± 2.6% for patients at least 60 years old and 75.9% ± 9.3% for patients younger than 60 years. Freedoms from SVD by explant reoperation at 10 years for MVR were 95.3% ± 7.8% for patients at least 70 years old and 84.0% ± 9.3% for patients younger than 70 years. Hemodynamic performance data at 1 year for AVR (sizes 21-27 mm) were mean systolic gradient range 13.7 ± 4.8 to 10.3 ± 3.2 mm Hg and effective orifice area range 1.5 ± 0.3 to 2.5 ± 0.4 cm(2). For MVR (sizes 25-31 mm), data were mean diastolic gradient range 6.7 ± 1.7 to 3.7 ± 0.9 mm Hg and effective orifice area range 1.9 ± 0.3 to 2.4 ± 0.6 cm(2). CONCLUSIONS Overall performance of Mosaic porcine bioprosthesis to 12 years is satisfactory. Freedoms from SVD by explant reoperation were most satisfactory for aortic position in patients at least 60 years old and mitral position in patients at least 70 years old. Overall actuarial freedom from SVD by explant reoperation is encouraging for patients with MVR.

Clinical results of the Medtronic Mosaic porcine bioprosthesis up to 13 years

BACKGROUND The Mosaic bioprosthesis is a third-generation stented porcine bioprosthesis combining physiologic fixation and alpha-amino oleic acid (AOA) antimineralisation treatment to improve haemodynamic performance and durability. This single-centre study reports the clinical results, including haemodynamic performance, of the Mosaic bioprosthesis after implant in aortic or mitral position. METHODS Between February 1994 and October 1999, 255 patients with aortic valve replacement (AVR; mean age: 67 years, range: 23-82 years) and 47 patients with mitral valve replacement (MVR; mean age: 67 years, range: 41-84 years) were enrolled in this prospective non-randomised clinical trial. Follow-up visits were performed 30 days and 6 months after implant and annually thereafter. The cumulative follow-up was 1976.2 patient-years (pt-yrs) after AVR (median: 8.3 years, maximum: 14.0 years) and 336.9 pt-yrs after mitral valve replacement (MVR) (median: 8.2 years, maximum: 13.3 years). RESULTS After AVR, mean systolic gradient and effective orifice area at 4, 8 and 13 years follow-up were 13.3+/-5.6, 15.5+/-7.7 and 16.0+/-7.2 mmHg and 1.8+/-0.5, 1.8+/-0.5 and 1.7+/-0.4 cm(2). After MVR, respective data were 4.7+/-2.1, 4.3+/-1.2 and 5.0 mmHg (only one recording) and 2.2+/-0.7, 2.3+/-0.6 and 1.8 cm(2). Transvalvular regurgitation at 13-year follow-up was mild or less in both the AVR and MVR patients. Thirteen-year survival was 63.1+/-4.5% in the AVR group and 51.2+/-13.6% in the MVR group. Early mortality after AVR and MVR was 1.2% and 0.0%, respectively; late mortality was 3.2%pt-yr(-1) and 3.3%pt-yr(-1), including a valve-related/unexplained mortality of 1.1%pt-yr(-1) and 0.9%pt-yr(-1). Freedom from adverse events in the AVR and MVR group was permanent neurological event: 97.4+/-1.2% and 96.0+/-3.9%; valvular thrombosis: 97.8+/-1.1% and 100%; structural valve deterioration: 84.8+/-7.8% and 93.8+/-6.1%; explant: 73.3+/-7.3% and 89.3+/-6.5%. CONCLUSIONS The Mosaic bioprosthesis demonstrates excellent clinical performance and safety after 13 years of follow-up. Continued follow-up will determine whether this new design will provide increased durability.

Transfemoral Tricuspid Valve Repair Using a Percutaneous Mitral Valve Repair System.

There is increasing evidence that severe tricuspid regurgitation (TR) is associated with a poor prognosis. Recently, less invasive transcatheter tricuspid repair technologies are emerging as alternative therapeutic options for high surgical risk patients. One percutaneous mitral valve repair system

Factors influencing survival and postoperative quality of life after mitral valve reconstruction

OBJECTIVE Mitral valve reconstruction (MVR) is the preferred treatment for regurgitant lesions. Clinical benefit is well documented, but comparative data scrutinising factors influencing survival and postoperative quality of life (QOL) in different subsets of patients are missing. We hypothesised that mitral valve reconstruction for mitral regurgitation benefits the patients, regardless of the valve pathology. METHODS In this study, 663 consecutive patients undergoing mitral valve reconstruction using Carpentier techniques were assigned to four different groups. Aetiology of mitral regurgitation was degenerative (DEG) in 372 (56.1%) patients and ischaemic (ISC) in 157 (23.6%). Cardiomyopathy (CMP) was present in 23 (3.4%) cases and combined degenerative regurgitation plus coronary artery disease (DEG+CAD) in 111 (16.7%) patients. Survival was evaluated using a Cox proportional hazards model. Postoperative QOL was assessed using the short form (SF)-36 questionnaire in a multivariate analysis of covariance. RESULTS The overall 30-day mortality was 1.1% (0.3%, 1.9%, 0% and 2.7% for groups DEG, ISC, CMP and DEG+CAD, respectively). The median preoperative NYHA class and grade MI was 3 and evenly distributed between groups. After a mean follow-up of 4.1+/-3.4 years, MVR proved to be effective in all groups with 90.3% of patients in the NYHA classes I and II (p<0.001). At 5 years, unadjusted survival was 90.3%, 69.7%, 50.5% and 86.2%. However, after correcting for age, ejection fraction, chronic obstructive pulmonary disorder (COPD), renal insufficiency and the preoperative NYHA class, survival in groups ISC and DEG+CAD was comparable. Group allocation was not a predictor for late death. Postoperative QOL was inferior in female patients in all SF-36 scales (p<0.01) and was impaired by co-morbidities. QOL scores were best for patients in group DEG and worst in group CMP. In a multivariate model correcting for gender, age and co-morbidities (COPD, treated diabetes, renal insufficiency, subjective heart rhythm, preoperative NYHA class and previous myocardial infarction), postoperative QOL was comparable between groups. For the majority of patients with degenerative MR, postoperative life expectancy as well as QOL is similar to a normal population. CONCLUSIONS MVR was safely and effectively accomplished in all groups. Survival and postoperative QOL was determined by left ventricular function and co-morbidities rather than MR aetiology.

A steel band in addition to 8 wire cerclages reduces the risk of sternal dehiscence after median sternotomy.

BACKGROUND Sternal dehiscence after full median sternotomy may result in wound-healing disorders, including osteomyelitis. The consequences are extended hospitalization, plastic surgery, stress for the patient, and increased costs. Stable closure of the median sternotomy plays a crucial role in the avoidance of sternal dehiscence and osteomyelitis. METHODS All patients who underwent full sternotomy from January 1999 until December 2001 were investigated with respect to the incidence of sternal dehiscence. Since January 2000, patients supposed to be at risk for sternum dehiscence were more frequently treated with an Ethicon steel band at the third intercostal space in addition to standard osteosynthesis with 8 wire cerclages. RESULTS Since the introduction of this method, the incidences of sternal dehiscence and sternal wound infections decreased from 2.9% and 0.9 %, respectively, in 1999 to 0.3% and 0.2%, respectively, in 2001. This decline resulted in shorter postoperative hospital stays, less stress for the patients, and substantial reductions in postsurgical costs. CONCLUSIONS A steel band used in addition to standard osteosynthesis with 8 wire cerclages is a safe and effective procedure resulting in a statistically significant decrease in the frequency of sternal dehiscence.

Rhabdomyolysis following cardiopulmonary bypass and treatment with enoximone in a patient susceptible to malignant hyperthermia.

SEVERE hypercapnia, muscle rigidity, hyperthermia, and rhabdomyolysis characterize malignant hyperthermia (MH) in fulminant form. However, during cardiac operations using cardiopulmonary bypass (CPB), typical symptoms of MH may not be present. We observed a patient undergoing aortic valve replacement, in whom severe postoperative rhabdomyolysis and arrhythmias developed after treatment with enoximone during CPB and cardioplegic arrest. Subsequently, in vitro contracture testing showed that the patient was susceptible to MH.

Recombinant hirudin as an anticoagulant during cardiac operations: experiments in a pig model.

OBJECTIVE The efficacy and safety of recombinant hirudin (r-hirudin) compared with heparin as an anticoagulant during open-heart surgery has been studied in a pig model. METHODS A total of 18 Göttingen minipigs were randomly divided into three treatment groups and subjected to cardiopulmonary bypass for 1 h. Heparin-treated animals received a bolus of unfractionated heparin of 400 IU/kg body weight. Recombinant hirudin was given by a bolus injection of 1 mg/kg body weight, followed by a 1 h lasting infusion of 1 mg/kg body weight per h. The heparin-anticoagulated animals and one group of the hirudin-treated animals additionally received aprotinin at a dosage of 17500 KIU/kg body weight (KIU, kallikrein inhibitory units). In the second group of r-hirudin-treated animals, the aprotinin was replaced by saline. RESULTS The extracorporeal circuit remained patent for a 1 h pump period in all of the animals studied. There was no evidence of vascular occlusion or clot formation in the r-hirudin-treated animals. The anticoagulant efficacy of the hirudin protocol used is further demonstrated by the results of electron-microscopical scans of the pump-line filters. Fibrin deposits were visible only in the heparin-treated animals and not in r-hirudin-treated pigs. Despite this strong anticoagulant effect, there was no evidence of an increased bleeding tendency in r-hirudin-treated pigs. Moreover, histological studies showed a statistically significant (P < 0.05) higher incidence of tissue bleeding in the heparin/aprotinin-treated animals compared with the r-hirudin/aprotinin-treated pigs. Studying the platelet function, a statistically significant (P < 0.01) better preserved ADP- and collagen-induced platelet aggregation was seen in the r-hirudin/aprotinin-treated animals when compared with heparin/aprotinin-treated animals. CONCLUSIONS These data demonstrate that r-hirudin can be used successfully as an alternative anticoagulant to heparin during cardiac operations including cardiopulmonary bypass. The better preservation of platelet function suggests that r-hirudin may reduce the postoperative risk of bleeding.