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Biomedical subjects

M De Carlo

Publications and source records attributed to M De Carlo.

At least 37 records · Page 2Linked to original sources
PubMed1999

Cardiopulmonary exercise testing in patients with 21mm St. Jude Medical aortic prosthesis.

BACKGROUND AND AIM OF THE STUDY: Small-sized prostheses may be associated with high transprosthetic gradients, particularly in patients with a body surface area (BSA) >1.70m2, affecting left ventricular mass regression, symptom improvement and long-term survival. However, the influence of such gradients on exercise tolerance has not been clearly defined. The study aim was to verify the utility of cardiopulmonary exercise testing (CPX) in detecting patient-prosthesis mismatch, and to identify the clinical and echocardiographic data that predict exercise tolerance at CPX in patients with a 21mm St. Jude Medical (SJM) aortic prosthesis. METHODS: Twenty patients (one male, 19 females; mean age 66 +/- 9 years) with a 21 mm SJM prosthesis were evaluated by means of 2D echocardiography and CPX at 36 +/- 10 months after operation. Patients were divided into groups on the basis of a BSA of <1.70 m2 (group 1, n = 12) or > or =1.70 m2 (group 2, n = 8). RESULTS: At echocardiography, left ventricular mass reduction was 16 +/- 10% versus 9 +/- 6% in groups 1 and 2, respectively, mean gradient (MG) was 15 +/- 6 versus 17 +/- 4 mmHg (p = NS), effective orifice area index (EOAi) 0.86 +/- 0.10 versus 0.79 +/- 0.09 cm2/m2 (p = 0.05). At CPX, group 2 patients showed a significantly lower exercise duration (p = 0.02), maximum workload (p = 0.02), peak O2 uptake (p = 0.01), anaerobic threshold (AT) (p = 0.03), ventilatory equivalent for CO2 at AT (p = 0.007), and O2 cost of work (p = 0.03). Group 1 patients showed a ventilatory origin for their effort dyspnea, while group 2 patients showed a significant circulatory component. At multivariate analysis, BSA, age, EOAi and MG were independent predictors of CPX results. CONCLUSIONS: In patients with a 21 mm aortic SJM prosthesis and a BSA > or =1.70m2, CPX allows detection of patient-prosthesis mismatch, in terms of impaired exercise tolerance due to circulatory causes. CPX results can be anticipated on the basis of the patient's BSA, age, EOAi and MG. In these patients, technical solutions allowing implantation of a larger prosthesis should be considered whenever an active lifestyle is anticipated after aortic valve replacement.

Aged↗
PubMed1998

Early results of transmyocardial revascularization with a holmium laser.

BACKGROUND: Transmyocardial laser revascularization (TMLR), a surgical technique designed to improve perfusion in the ischemic myocardium by creating transmural channels, has been performed thus far using a carbon dioxide laser, with apparently gratifying early results. We have investigated clinically TMLR using a holmium laser as sole therapy for patients with coronary artery disease that is not amenable to traditional treatment such as coronary artery bypass grafting or percutaneous transluminal coronary angioplasty. METHODS: From November 1995 to December 1996, 16 patients underwent TMLR using a holmium laser. Their mean age was 68 +/- 6 years and 75% were men. Previous coronary artery bypass grafting or percutaneous transluminal coronary angioplasty had been performed in 81% and 31% of the patients, respectively. Before operation, their mean anginal class was 3.4 +/- 0.5 and their mean left ventricular ejection fraction was 0.49 +/- 0.06. Six patients had unstable angina. RESULTS: There were no operative deaths. The mean duration of TMLR was 27 +/- 13 minutes and the mean duration of the entire operation was 120 +/- 40 minutes. There were no major postoperative complications and the mean hospital stay was 8 +/- 4 days. There were 2 late deaths, 1 that occurred 40 days after TMLR as a result of stroke and 1 that occurred 4 months after TMLR as a result of myocardial infarction. Current survivors have been followed up for a mean of 10 +/- 4 months (range, 3 to 15 months), with 7 patients followed up for 1 year. At last follow-up, the mean anginal class had decreased to 1.8 +/- 0.7 (p = 0.001) and the patients had increased exercise tolerance and a reduced number of hospitalizations. However, no statistically significant changes in the percentage of segments with fixed or reversible ischemia and no statistically significant differences in the viability scores of lased and nonlased segments were observed. CONCLUSIONS: Transmyocardial laser revascularization using a holmium laser is a simple technique with low operative risk and low morbidity. Early results confirm that clinical improvement is obtained in most patients, although significant changes in myocardial perfusion are not evident in the short term.

Aged↗
PubMed1998

Valve-related complications in elderly patients with biological and mechanical aortic valves.

BACKGROUND: Controversy still exists about the choice of aortic prosthesis in elderly patients. This study investigates valve- and anticoagulant-related morbidity and mortality in elderly patients after aortic valve replacement (AVR) with a biologic (BP) or mechanical prosthesis (MP). METHODS: Between 1981 and 1995, 355 consecutive patients aged 70 years or older (mean, 74+/-4 years; range, 70 to 87 years) underwent isolated AVR. There were 222 (63%) replacements with an MP and 133 (37%) with a BP. Mean follow-up was 3.7+/-2.8 years (range, 3 months to 15 years), with a total follow-up of 1,214 patient-years. RESULTS: Hospital mortality was 7.6% (27 of 355), decreasing to 4.6% in the last 3 years. There were 55 late deaths, 33 in patients with MP and 22 in those with BP. At 10 years there was no significant difference between MP and BP recipients in the actuarial estimates of survival (51%+/-8% versus 33%+/-13%), freedom from valve-related death (82%+/-7% versus 72%+/-12%), and freedom from thromboembolism (84%+/-7% versus 94%+/-3%). In contrast, 10-year freedom from anticoagulant-related hemorrhages was 74%+/-8% for MP and 99%+/-1% for BP (p = 0.02). Only 1 structural deterioration occurred, in a patient with BP. CONCLUSIONS: Satisfactory early results can be obtained in elderly patients after AVR with both MP and BP. The comparable low late survival in the two groups was predominantly influenced by non-valve-related deaths. A higher incidence of anticoagulant-related hemorrhages limits the use of MP in elderly patients. Thus, in this population, BP should be preferred not just on the basis of their expected longer durability, but mainly to avoid the risk of anticoagulant-related hemorrhages.

Actuarial Analysis↗
PubMed1998

Rehabilitation and use of protective devices in hand and wrist injuries.

Hand and wrist injuries are common among athletes. Although the hand does not often bear weight and these injuries do not always sideline an athlete, careful attention must be paid when treating injuries of the hand and wrist. Rehabilitation is given for common injuries of the hand and wrist, including exercises and protective splints and braces. Details on how to fabricate a playing cast for athletes are also discussed.

Athletic Injuries↗
PubMed1998

Predicting outcome after myocardial revascularization in patients with left ventricular dysfunction.

In order to identify the risk factors which could predict outcome after coronary artery bypass grafting in patients with left ventricular dysfunction, 80 consecutive patients with an ejection fraction < or = 30%, who underwent isolated coronary artery bypass grafting at the authors' centre between January 1994 and May 1996 were evaluated. Preoperatively, mean(s.d.) ejection fraction was 27.1(3.8)%, 56 patients (70%) had angina, and 56(70%) were in New York Heart Association (NYHA) functional class III or IV. There were five operative deaths, with a hospital mortality rate of 6.3%. Significant risk factors for hospital death were NYHA class IV, preoperative ventricular arrhythmias and left ventricular end-diastolic volume index > 110 ml/m2. At mean follow-up of 15(7) (range 6-30) months, there were six late deaths, five of which were from cardiac causes. Actuarial survival rate at 2 years was 82(5)% and freedom from cardiac death 84(5)%. Risk factors for overall mortality from cardiac causes were preoperative grade 2 mitral regurgitation, associated with left ventricular dilatation, and renal dysfunction (creatininaemia > or = 180 micromol/l). At follow-up, mean ejection fraction was 37.5(8.4)%, and the overall functional status had improved: 12 patients (18%) had angina and eight (12%) were in NYHA class III and IV. Myocardial revascularization in patients with left ventricular dysfunction can be performed with acceptably low operative risk, good survival rate at 2 years, and functional status improvement. Patients with extensive ventricular dilatation, associated with significant mitral regurgitation, have a lower life expectancy and less functional benefits from coronary artery bypass grafting. These patients are better treated by cardiac transplantation.

Aged↗
PubMed1998

Transmyocardial holmium laser revascularization: feasibility of a thoracoscopic approach.

OBJECTIVE: Creation of transmyocardial channels from the epicardium to the left ventricular cavity with the use of a laser is a modern approach in the treatment of patients with chronic ischemic heart disease unsuitable for coronary angioplasty or bypass grafting. We present the results of transmyocardial laser revascularization (TMLR) with a holmium laser as sole therapy in 22 patients operated on between November 1995 and February 1997. METHODS: There were five females (23%) and 17 males (77%), with a mean age of 67+/-7 years (range 53-74 years). Previous myocardial revascularization had been performed in 77% of the patients. Pre-operatively, 12 patients (55%) were in angina class III and ten (45%) in class IV (mean 3.5+/-0.5); unstable angina was present in seven patients (32%). In 20 patients, TMLR was performed through a limited thoracotomy, while in two a thoracoscopic approach was used. Each patient received a mean of 33+/-8 channels in 27+/-13 min, while total operation lasted 130+/-28 min. RESULTS: There were no hospital deaths and no major post-operative complications. Mean hospital stay was 7+/-3 days; the two patients undergoing thoracoscopic TMLR were discharged after 4 and 5 days, respectively. Two deaths were observed after 40 days and 4 months after TMLR, due to stroke and myocardial infarction. Mean follow-up of current survivors is 10+/-6 months (range 3-15 months), with seven patients followed for over 12 months. At last follow-up, mean angina class is 1.9+/-0.6 (P < 0.001). A significant increase in exercise tolerance and a reduction of the number of hospitalizations for angina were also observed. However, no significant changes in myocardial perfusion were observed. CONCLUSIONS: The present study demonstrates that: (1) TMLR with a holmium laser yields clinical improvement in the majority of patients with severe angina unsuitable for conventional surgical treatment, (2) gratifying results in terms of improved anginal status and exercise tolerance are achieved, despite the lack of significant changes in myocardial perfusion at early follow-up and (3) TMLR through a thoracoscopic approach is a feasible procedure.

Aged↗
PubMed1998

Ascending aorta dissection after aortic valve replacement.

BACKGROUND AND AIMS OF THE STUDY: The surgical management of patients with aortic valve disease associated with ascending aortic dilatation is a controversial issue. Structural abnormalities of the aortic wall predispose to further aortic enlargement and possibly to ascending aortic dissection (AAD). Indications to concomitant replacement of aortic valve and ascending aorta have not yet been clearly defined. METHODS: We reviewed eight consecutive patients (seven males and one female) among 2202 patients who underwent aortic valve replacement (AVR) between 1982 and 1996. These eight were subsequently reoperated on because of AAD, between November 1987 and November 1996. Indications for initial AVR were aortic regurgitation due to annular ectasia in five patients, combined aortic stenosis and regurgitation in two, and isolated aortic stenosis in one patient. RESULTS: The interval between AVR and AAD ranged from four months to 10.5 years. Five patients presented with acute AAD, and three with chronic AAD. Retrospectively, four patients showed progressive increase in ascending aortic diameter after AVR, with a mean diameter of 72+/-9 mm at reoperation. Histological examination showed cystic medial necrosis in three patients, atherosclerotic degeneration in one patient, and normal aortic wall structure in one. There was one operative death due to low cardiac output; the hospital mortality rate was 13%. There were no late deaths and no major adverse events during a mean follow up of 5+/-3 years (range: 8 months to 10 years). CONCLUSIONS: In patients with ascending aortic dilatation (> or = 55 mm diameter), AVR alone may not prevent progression of aortic root enlargement. In these patients, the ascending aorta should be concomitantly replaced. Following AVR, all patients with mildly or moderately dilated aortic root should be periodically controlled to detect signs of progression of aortic dilatation.

Acute Disease↗
PubMed1998

[Myocardial revascularization with both internal mammary arteries].

BACKGROUND: The excellent results obtained with the use of the left internal mammary artery (IMA) for myocardial revascularization have led to the simultaneous use of other arterial conduits, particularly the right IMA. METHODS: The present study includes the first 100 consecutive patients with ischemic heart disease who underwent myocardial revascularization with in situ bilateral IMA grafted to branches of the left coronary artery, performed at our center. Ninety-six (96%) were males and four (4%) were females, with a mean age of 58 +/- 8 years (range, 35-75 years). The main indication for myocardial revascularization was angina in 83 patients (83%) and heart failure in 17 (17%). Seventy patients had three-vessel disease. RESULTS: Hospital mortality was 1%, with one death due to left ventricular failure. Three patients had perioperative myocardial infarction, six experienced ventricular arrhythmia, two had acute renal failure and nine respiratory insufficiency. Dehiscence of the sternal wound occurred in four patients, evolving in mediastinitis in one. All discharged patients were checked after 26 +/- 6 months (range, 12-38 months). There were two deaths, one because of cardiac failure and one sudden death, with a two-year survival rate of 97 +/- 2%. Five patients (5%) required hospitalization because of angina, and the angiographic study showed stenosis/occlusion of one or both IMAs in four cases. Thirty-five (38%) of the remaining patients underwent a coronarographic (25 patients) or transthoracic Doppler study (10 patients) to evaluate patency of the IMAs. The patency index was 100% for the left IMA and 94% for the right IMA. CONCLUSIONS: Myocardial revascularization with bilateral IMA in situ can be performed with low hospital mortality and morbidity. Sternal dehiscence is the worst complication and appears to be more frequent in diabetic and elderly patients. Mid-term results are satisfactory, with a good survival rate and freedom from major cardiac events. However, a longer follow-up is necessary to better appreciate the advantages of myocardial revascualarization with in situ bilateral IMAs.

Adult↗
PubMed1997

[Myocardial revascularization in patients with ischemic cardiomyopathy and left ventricular dysfunction].

In this study we evaluated the outcome of coronary artery bypass grafting (CABG) in patients with coronary artery disease and left ventricular dysfunction. The aim of the study was to identify the risk factors for operative and medium-term mortality. We evaluated 117 consecutive patients (98 men, 19 women, aged 42 to 84 years, mean 65 +/- 9) with ejection fraction (EF) < 40%, operated on from January 1994 to December 1995. Patients who had previously undergone CABG, or who had other procedures associated with CABG, were excluded. Preoperatively, mean EF was 32 +/- 5%; 65 patients (56%) had angina and 62 (53%) had congestive heart failure in NYHA functional class III and IV. Hospital mortality rate was 5% (i.e. 6 deaths). At multivariate analysis significant risk factors were: NYHA functional class IV and moderate/ severe mitral regurgitation. All patients were evaluated at a mean follow-up time of 13 +/- 8 months (range 3 to 30); 9 deaths occurred, 7 due to cardiac causes. Actuarial survival rate at 24 months was 85 +/- 4%; freedom from death due to cardiac causes was 87 +/- 4%. Significant risk factors for medium-term mortality at multivariate analysis were age, moderate/severe mitral regurgitation and marked impairment of regional myocardial contractile function, evaluated by the wall motion score index (> or = 2.25). At follow-up the majority of patients showed improved clinical conditions: mean EF was 40 +/- 8%; 8 patients (8%) had angina and 12 (12%) were in NYHA functional class III and IV. Myocardial revascularization in patients with coronary artery disease and left ventricular dysfunction is characterized by low operative risk and good survival rate at 2 years, with improvement of both angina and congestive heart failure. The best results were obtained in those patients who preoperatively showed the best regional contractile function, even though the global EF was poor, and in those with signs of reversible left ventricular dysfunction, such as angina or documented myocardial viability.

Adult↗
PubMed1997

[Transmyocardial revascularization with a holmium laser: preliminary results].

BACKGROUND: Transmyocardial laser revascularization (TMLR) aims to improve perfusion of the ventricular wall via laser-created transmural channels. We present the results of TMLR with a holmium laser as sole therapy in patients with angina refractory to medical treatment and extensive coronary artery disease unsuitable for angioplasty or coronary artery by-pass grafting. METHODS: From November 1995 to February 1997, twenty-two patients underwent isolated TMLR with a holmium laser. Five patients (23%) were female; the mean age was 67 +/- 7 years (range 53 to 74 years). Previous myocardial revascularization procedures had been performed in 17 patients (77%). Mean preoperative angina class was 3.4 +/- 0.5 and unstable angina was present in 7 patients (32%). RESULTS: There were no hospital deaths. The only postoperative complications were transient supraventricular arrhythmias in 6 patients (27%). Each patient received a mean of 33 +/- 8 channels in 27 +/- 13 minutes. There were two late deaths, 40 days and 4 months after TMLR, due to stroke and myocardial infarction, respectively. Mean follow-up duration was 8 +/- 5 months (range 40 days-15 months). The mean number of hospitalizations due to angina fell from 4.9 +/- 1.5 in the 6 months before TMLR to 1.5 +/- 1.0 in the 6 months following surgery (p < 0.001). At follow-up, mean angina class had significantly improved (1.8 +/- 0.6, p < 0.001), as well as effort tolerance, which increased from a mean of 3.5 +/- 1.4 minutes to 5.1 +/- 1.7 minutes (p = 0.01). 201Tl SPECT at 3 and 6 months did not show any significant changes in the segmental perfusion of the lased and unlased areas. CONCLUSIONS: TMLR with a holmium laser is a simple procedure with low operative mortality and morbidity. Short-term results confirm that clinical improvement is obtained in most patients, although this is not supported by significant changes in myocardial perfusion at short-term follow-up.

Aged↗
PubMed1994

Interstitial exclusion of IgG in rat tissues estimated by continuous infusion.

Interstitial exclusion, defined as the fraction of interstitial fluid volume inaccessible to a solute, was evaluated for immunoglobulin G (IgG) in selected tissues of rats by a method previously applied to serum albumin (29). IgG distribution volumes were also measured for intestine. 125I-labeled rat IgG was infused for 5 or 7 days (n = 4 rats each) with an implanted osmotic pump (Alzet). At the termination of infusion, the rat was anesthetized, nephrectomized, and injected with 51Cr-labeled EDTA (4 h) to label total extracellular fluid volume and 131I-labeled bovine IgG (5 min) to label plasma volume. Samples of skin, muscle, and tendon were assayed for total and extractable tracer activity. Interstitial fluid from these tissues was sampled postmortem with nylon wicks for assay of 125I-labeled IgG and endogenous albumin and IgG. Exclusion of IgG was calculated from the difference between extravascular 125I-labeled IgG and 51Cr-labeled EDTA distribution volumes. In contrast to our previous experience with tracer albumin, 125I-labeled IgG was not fully extractable from minced skin, muscle, or tendon by isotonic saline; only 71-83% was recovered under conditions that eluted 92-96% of tracer albumin and 94-99% of tracer EDTA. We conclude that approximately 20% of extravascular 125I-labeled IgG in these tissues is sequestered or bound in the interstitium. Calculation of IgG fractional exclusion from extractable tracer yielded the following values (means +/- SE, n = 8 rats): leg muscles 0.37 +/- 0.09, leg skin 0.44 +/- 0.03, back skin 0.36 +/- 0.04, tail skin 0.40 +/- 0.08, and tail tendon 0.55 +/- 0.04.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Acute anterior cruciate ligament injury.

This article covers a retrospective investigation of the time from an acute anterior cruciate ligament tear to the intra-articular reconstruction of the tear. The study was conducted to find a specific time that would result in greater knee strength, range of motion (ROM) and/or patient satisfaction after surgery. The patient population was divided into three groups, and the Cybex, ROM and modified Noyes' questionnaire scores were evaluated for each group. The patient data base was collected through the Physical Therapy Department at Methodist Sports Medicine Center in Indianapolis. The analyses indicated that patients who delayed surgery for 22 or more days had better ROM scores, specifically full extension. The results did not show any correlation between the time from injury to surgery and the postoperative strength or patient satisfaction of the involved knee. Further analyses also indicated that patients who delayed surgery for one week or more and who underwent an accelerated rehabilitation program after surgery attained full range at a similar rate as those who delayed surgery for 22 or more days.

Adolescent↗