Biomedical subjects

Daniel Zimpfer

Publications and source records attributed to Daniel Zimpfer.

6 recordsLinked to original sources

PubMed2003

Coronary reoperations: recurrence of angina and clinical outcome with and without cardiopulmonary bypass.

BACKGROUND: We compared our experience of minimal tissue dissection and target vessel revascularization without cardiopulmonary bypass (CPB) with the standard procedure of total dissection of the heart and complete revascularization with CPB in patients who had elective reoperative coronary artery bypass grafting (redo-CABG). METHODS: We analyzed recurrence of angina and clinical outcome in 118 patients who had elective redo-CABG between January 1995 and April 2002. Seventy-four patients had redo-CABG with CPB, and 44 patients had redo-CABG without CPB. RESULTS: Perioperative outcome was comparable with regard to morbidity and mortality rates. At follow-up, the mean Canadian Cardiovascular Society score was 1.3 +/- 0.6 in patients who had redo-CABG with CPB and 1.7 +/- 0.8 in patients who had redo-CABG without CPB (p = 0.02). At follow-up, patients who had redo-CABG without CPB had a higher rate of recurrence of angina (log rank = 0.001) and higher use of nitrates (p = 0.015). Target vessel revascularization was an independent predictor of recurrence of angina in younger patients (< 75 years; p = 0.012) but not in the elderly (> or = 75 years; p = 0.142). CONCLUSIONS: In elective redo-CABG patients, minimal tissue dissection and target vessel revascularization without cardiopulmonary bypass did not add significant benefit with regard to perioperative morbidity and mortality. The unsatisfactory relief of symptoms does not seem to justify target vessel revascularization by a less invasive approach. Therefore, this technique should be offered exclusively to patients at high risk with complete revascularization using CPB, such as the elderly.

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PubMed2003

Neurocognitive deficit following mitral valve surgery.

OBJECTIVE: Neurocognitive deficit is an important complication in patients undergoing open heart surgery. The aim of this prospective, contemporary study was to objectively measure neurocognitive brain function following mechanical mitral valve replacement and mitral valve repair. METHODS: Forty consecutive, unselected patients (mechanical valve replacement n=20, mean age 65+/-14; valve repair n=20, mean age 64+/-7, P=0.896) entered this prospective, contemporary study. Neurocognitive function was objectively measured by means of P300 auditory evoked potentials (peak latencies, ms) and two standard psychometric tests (Mini Mental State Examination, Trailmaking Test A (TTA)), preoperatively, 7 days and 4 months postoperatively. RESULTS: Before operation, neurocognitive brain function was comparable in both patients groups (mechanical valve replacement versus valve repair: P300 potentials 374+/-25 versus 378+/-46 ms; P=0.791 and TTA 57+/-15 versus 54+/-10 s; P=0.552). Following mechanical valve replacement, neurocognitive function continuously worsened (7 day-follow-up: P300 potentials 392+/-28, P=0.001 versus preop and TTA 65+/-17, P=0.0001; 4-month follow-up: P300 potentials 406+/-39, P=0.0004; TTA 69+/-17, P=0.0001). Interestingly, neurocognitive brain function was unaffected in patients undergoing valve repair (7-day follow-up: P300 potentials 386+/-40, P=0.890 versus preop and TTA: 53+/-10, P=0.644; 4-month follow-up: P300 potentials 374+/-36, P=0.166 and TTA 54+/-11, P=0.147). At 4-month follow-up, patients with mechanical prostheses performed worse as compared to valve repair (P300 potentials: P=0.024; TTA P=0.014). CONCLUSION: As shown by P300 auditory evoked potentials and Trailmaking Test A, there is marked neurocognitive damage related to mechanical valve replacement, whereas mitral valve repair does not affect neurocognitive function. This finding supports the beneficial effect of mitral valve repair over mechanical valve replacement in the decision-making tree of borderline cases, which are suitable for both types of procedure.

Adult↗

PubMed2003

Neurocognitive deficit following aortic valve replacement with biological/mechanical prosthesis.

OBJECTIVE: The aim of this study was to objectively measure neurocognitive deficit following aortic valve replacement with a mechanical or biological prosthesis. MATERIALS AND METHODS: In this prospective, contemporary study we followed 82 consecutive patients undergoing isolated aortic valve replacement with either a mechanical (n=29, mean age=52+/-7 years) or a biological (n=53, mean age=68+/-10 years) valve prosthesis. Neurocognitive function was measured by means of objective P300 auditory evoked potentials (peak latencies, ms) and two standard psychometric tests (Trailmaking Test A, Mini Mental State Examination) before the operation, 7 days and 4 months after the operation, respectively. RESULTS: Since P300 peak latencies increase with age, preoperative P300 measures are lower in patients receiving mechanical valves (360+/-35 ms, mean 52 years) as compared to patients receiving biological valves (381+/-34 ms, 68 years, P=0.0001). Seven days after surgery, P300 peak latencies were prolonged (-worsened) in both groups as compared to preoperative values (mechanical valves: 384+/-36 ms; P=0.0001 and biological valves: 409+/-39 ms; P=0.0001). Although on a different level (-age-related), this development was comparable within both groups (P=0.800). Four months after surgery, P300 peak latencies normalized in the mechanical valve group (372+/-27 ms, P=0.857 versus preoperative), while in contrast in the biological valve group they remained prolonged (417+/-37 ms, P=0.0001). We found no difference within patients receiving different types of biological or mechanical aortic valves. CONCLUSION: Postoperative neurocognitive damage is not reversible in (-elderly) patients with biological aortic valve replacement, while in contrast postoperative neurocognitive damage is reversible in (-younger) patients with mechanical valve replacement. For this contrary development, age seems to be most important, whereas damage related to type of valve prosthesis may be overestimated.

Adult↗

PubMed2003

Redo coronary artery bypass grafting with and without cardiopulmonary bypass in the elderly.

OBJECTIVES: Morbidity and mortality rates rise with increasing age in patients undergoing conventional redo coronary artery bypass grafting (CABG). The aim of this study was to compare our experience of minimal tissue dissection and target vessel revascularization without cardiopulmonary bypass (CPB) with the standard procedure of total dissection of the heart and complete revascularization with CPB for a population of elderly patients undergoing elective redo coronary artery CABG. METHODS: We retrospectively analyzed morbidity, mortality, and functional status of 47 patients older than 75 years who underwent redo CABG between January 1995 and June 2002. Thirty-one patients underwent redo CABG with CPB, and 16 patients underwent redo CABG without CPB. Follow-up end points were defined by patient survival, freedom from recurrence of angina (Canadian Cardiovascular Society [CCS] score), freedom from rehospitalizations and reinterventions, and the need for antianginal medication. RESULTS: There were 2 perioperative deaths (2 in the CPB group versus 0 in the group without CPB; P =.151). Nonfatal myocardial infarction occurred in 3 patients (3 in the CPB group versus 0 in the group without CPB; P =.082). Major adverse cardiac events occurred in 5 patients (5 in the CPB group versus 0 in the group without CPB; P =.058). At the time of follow-up, the mean CCS score of patients who underwent redo CABG with CPB was 1.5 +/- 0.8 and was 1.6 +/- 0.7 for patients who underwent redo CABG without CPB (P =.432). The rates of angina recurrence (16% with CPB versus 13.3% without CPB; P =.243), use of nitrates (8.7% with CPB versus 14.3% without CPB; P =.542), and survival (89% with CPB versus 93% without CPB; P =.238) were very comparable for the two groups. CONCLUSIONS: In this high-risk subgroup of patients, those patients who underwent target vessel revascularization without CPB showed a trend toward a lower rate of major adverse cardiac events, and this procedure seems promising with regard to long-term outcome. Therefore, target vessel revascularization may be offered liberally to elderly patients who are at high risk in surgeries involving complete revascularization with CPB. Further studies are needed to elucidate the long-term outcome of target vessel revascularization for elderly patients undergoing redo CABG.

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PubMed2002

Cognitive deficit after aortic valve replacement.

BACKGROUND: Impairment of cognitive brain function after coronary artery bypass grafting (CABG) is well known. In contrast the potential neurocognitive damage related to aortic valve replacement (AVR) is uncertain. METHODS: In this contemporary case-matched control study we followed 30 patients (mean age 70 years) receiving isolated AVR with a biological prosthesis. A cohort of sex-and age-matched patients (n = 30, mean age 70 years) receiving CABG with cardiopulmonary bypass served as controls. Cognitive brain function was measured by means of auditory evoked P300 potentials (peak latencies, ms) before the operation and 7 days and 4 months after the operation. Additionally, two standard psychometric tests (Mini-Mental State Examination and the Trailmaking Test A) were performed. RESULTS: In preoperative measures there was no difference between patients undergoing AVR and patients undergoing CABG (AVR 378 +/- 37 ms, CABG 374 +/- 32 ms, p = 0.629). One week after surgery P300 peak latencies were prolonged (impaired) in both groups compared with preoperative values (AVR 405 +/- 43 ms, p = 0.001; CABG 398 +/- 44 ms, p = 0.004). At this point of follow-up there was no difference between the groups (p = 0.607). Finally, 4 months after surgery P300 auditory evoked potentials returned to normal in the CABG group (380 +/- 24 ms, p = 0.940) while in contrast in the valve group they continued to become prolonged (worsened) compared with preoperative values (410 +/- 47 ms, p = 0.005). At this time of follow-up P300 peak latencies were prolonged in AVR patients as compared with CABG patients (p = 0.032). The Trailmaking Test A and Mini-Mental State Examination failed to discriminate any difference. CONCLUSIONS: Four-month impairment of cognitive brain function is more pronounced in patients undergoing biological AVR as compared with age-matched control patients undergoing CABG. Further studies are needed to clarify the potential pathologic mechanisms causing an ongoing cognitive impairment in patients with biological aortic valve prostheses.

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PubMed2002

The vacuum-assisted closure system for the treatment of deep sternal wound infections after cardiac surgery.

BACKGROUND: The VAC system (vacuum-assisted wound closure) is a noninvasive active therapy to promote healing in difficult wounds that fail to respond to established treatment modalities. The system is based on the application of negative pressure by controlled suction to the wound surface. The method was introduced into clinical practice in 1996. Since then, numerous studies proved the effectiveness of the VAC System on microcirculation and the promotion of granulation tissue proliferation. METHODS: Eleven patients (5 men, 6 women) with a median age of 64.4 years (range 50 to 78 years) with sternal wound infection after cardiac surgery (coronary artery bypass grafting = 5, aortic valve replacement = 5, ascending aortic replacement = 1) were fitted with the VAC system by the time of initial surgical debridement. RESULTS: Complete healing was achieved in all patients. The VAC system was removed after a mean of 9.3 days (range 4 to 15 days), when systemic signs of infection resolved and quantitative cultures were negative. In 6 patients (54.5%), the VAC system was used as a bridge to reconstructive surgery with a pectoralis muscle flap, and in the remaining 5 patients (45.5%), primary wound closure could be achieved. Intensive care unit stay ranged from 1 to 4 days (median 1 day). Duration of hospital stay varied from 13 to 45 days (median 30 days). In-hospital mortality was 0%, and 30-day survival was 100%. CONCLUSIONS: The VAC system can be considered as an effective and safe adjunct to conventional and established treatment modalities for the therapy of sternal wound infections after cardiac surgery.

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