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Biomedical subjects

Leonard N Girardi

Publications and source records attributed to Leonard N Girardi.

At least 19 recordsLinked to original sources
PubMed2006

Epicardial beating heart cryoablation using a novel argon-based cryoclamp and linear probe.

OBJECTIVE: Epicardial, beating heart cryoablation for the treatment of atrial fibrillation may be limited by heat from intracardiac blood flow. We therefore evaluated the ability to create cryolesions using an argon-based cryoclamp device, which temporarily occludes blood flow and facilitates transmurality. METHODS: Six mongrel dogs underwent sternotomy. A clamp employing a 10-cm argon-based linear cryoablation device was used epicardially to isolate the pulmonary veins and left atrial appendage. After clamping of lesions, the probe was removed from the cryoclamp device, and the remaining linear lesions, analogous to the Cox maze III, were performed. Pulmonary vein stenosis was evaluated with the use of magnetic resonance imaging. Left atrial function and pulmonary venous flow velocities were assessed with transesophageal echocardiography. Transmurality was confirmed both electrically and histologically. Animals were then put to death at 30 days. RESULTS: All acute and chronic cryoclamp lesions produced conduction block. There was no change in right (RPV) or left pulmonary vein (LPV) diameter on the basis of magnetic resonance imaging at baseline and at planned death (RPV-1, 19.6 +/- 2.9 mm vs 16.9 +/- 2.8 mm, P = .22; RPV-2, 13.2 +/- 2.0 mm vs 11.8 +/- 1.6 mm, P = .22; and LPV, 12.2 +/- 2.4 mm vs 11.2 +/- 1.9 mm, P = .30). Left atrial function and pulmonary venous flow velocities were unchanged. Tissue sections determined transmurality in 93% of cryoclamp lesions and 84% of linear ablations performed with the 10-cm malleable probe. CONCLUSIONS: Epicardial application of this cryoclamp device on the beating heart produced transmural lesions, which persisted 30 days. Linear epicardial cryoablation was not as effective as the cryoclamp device at producing consistent transmural lesions. This novel, versatile device may be useful in treating patients with atrial fibrillation on the beating heart without cardiopulmonary bypass.

Animals↗
PubMed2006

Reoperations on the ascending aorta and aortic root in patients with previous cardiac surgery.

BACKGROUND: First time operations on the ascending aorta are performed with low mortality, few complications, and excellent long-term results. Reoperations for aortic pathology in patients with previous cardiac surgery carry significantly more risk. Technical issues during the procedure, as well as age, preoperative New York Heart Association class, and perioperative renal dysfunction, have been shown to contribute heavily to worse outcomes. We analyzed our results with aortic reoperations with the intent of further reducing surgical risk through alterations in surgical technique or patient selection. METHODS: From July 1997 until October 2005, 147 patients having previous cardiac surgery presented with aneurysm or dissection of the ascending aorta or root. Perioperative data were retrospectively analyzed. Morbidity, mortality, and risk factors for these events were calculated. RESULTS: Eight patients expired (5.4%) after their reoperation. Significant (p < 0.05) univariate risk factors for mortality included age greater than 75 years (< 0.001), previous coronary artery bypass grafting (CABG) (< 0.008), cardiopulmonary bypass greater than 240 minutes (< 0.01), need for intraaortic balloon pump support (< 0.001), need for new CABG (< 0.007), postoperative cerebrovascular accident (< 0.032), and tracheostomy (< 0.003). Age 75 years or older (p < 0.025) was the only significant variable for death by multivariate analysis. A majority of patients (n = 87, 60%) required circulatory arrest to complete their procedure. However, neither arch involvement nor type of aortic root procedure was predictive of perioperative mortality. CONCLUSIONS: Surgery on the ascending aorta and root in patients who have had previous cardiac surgery can be performed with low mortality. Advanced age and significant coronary disease may negatively influence surgical results.

Age Factors↗
PubMed2005

Surgical treatment of atrial fibrillation using argon-based cryoablation during concomitant cardiac procedures.

BACKGROUND: The development of ablative energy sources has simplified the surgical treatment of atrial fibrillation (AF) during concomitant cardiac procedures. We report our results using argon-based endocardial cryoablation for the treatment of AF in patients undergoing concomitant cardiac procedures. METHODS AND RESULTS: Sixty-three patients with AF who were undergoing concomitant cardiac procedures had the same left atrial endocardial lesion set using a flexible argon-based cryoablative device. Mean age was 65.1+/-1.3 years. Sixty-two percent had permanent AF, whereas 38% had paroxysmal AF. Mean duration of AF was 30.5+/-4.8 months. Mean left atrial diameter was 5.5+/-0.1 cm. Mean ejection fraction was 45+/-1.4%. All endocardial lesions were performed for 1 minute once tissue temperature reached -40 degrees C. Follow-up echocardiograms were obtained to determine freedom from AF. Kaplan-Meier analysis demonstrated an 88.5% freedom from AF rate at 12 months. Ablation time was 16.8+/-0.6 minutes. There were no in-hospital deaths and no strokes. Twelve patients (19%) required postoperative permanent pacemaker placement. CONCLUSIONS: Cryoablation using this flexible argon-based device for the treatment of AF during concomitant cardiac procedures was safe and effective, with 88.5% of patients free from AF at 12 months.

Aged↗
PubMed2005

Does cross-clamping the arch increase the risk of descending thoracic and thoracoabdominal aneurysm repair?

BACKGROUND: Descending thoracic and thoracoabdominal aortic aneurysms may arise in the distal aortic arch. Repair of these aneurysms has been associated with increased morbidity and operative mortality. Complex surgical and endovascular techniques have reduced the risks for this cohort. We examined outcomes utilizing an approach based on simple cross-clamping of the arch. METHODS: From July 1997 to January 2004, 272 consecutive patients had aneurysm repair through the left chest. Twenty-nine requiring profound hypothermic circulatory arrest (PHCA) were excluded. Two hundred and forty-three were divided into two groups: group I (n = 60) had distal arch involvement and required cross-clamping proximal to the left subclavian artery. Group II (n = 183) were cross-clamped distal to the subclavian. Adjuncts for neurologic and renal protection were utilized as needed. RESULTS: In-hospital mortality for all 243 patients was 3.7%. There was no difference in mortality between groups (I, 3.3% vs II, 3.8%). Group I patients also had similar rates of paraplegia (I, 0% vs II, 2.2%), stroke (I, 1.2% vs II ,1.1%), and renal failure (I, 1.7% vs II, 5.5%). Group I patients had significantly more recurrent nerve palsies (I, 33% vs II, 4.9%) although this did not translate into a higher incidence of respiratory failure. CONCLUSIONS: Repair of thoracic aneurysms arising in the distal arch can be repaired with a technique based on simple cross-clamping without an increase in mortality or major neurologic injury. Recurrent nerve palsy is much more common with this approach but is well-tolerated without increasing the need for tracheostomy.

Acute Kidney Injury↗
PubMed2005

Comparison of open versus bedside percutaneous dilatational tracheostomy in the cardiothoracic surgical patient: outcomes and financial analysis.

BACKGROUND: The clinical and financial outcomes of a change in practice from traditional tracheostomy (open) to bedside percutaneous dilatational tracheostomies (PDT) was evaluated in patients who underwent cardiothoracic surgery. METHODS: During 3 years, 86 tracheostomies were performed in more than 4,000 patients who underwent cardiac surgery, 59 open and 27 PDT. A retrospective analysis was performed comparing clinical and financial outcomes of the two groups. RESULTS: There were no significant differences in demographics, medical histories, operations, or complications between open and PDT except the open group experienced more postoperative arrhythmias (70% [41 of 59] versus 44% [12 of 27], p < 0.05). Total savings associated with 1 year of PDT was $84,000, for a projected discounted savings of $283,000 during the study period. A sensitivity analysis of critical economic variables (number of tracheostomies per year, cost of operating room per minute, cost of intensive care unit bed per day) was included to evaluate the impact on cost savings. The net present value analysis, which discounts future savings by an appropriate interest rate, yielded a range of projected savings of PDT more than 5 years of $73,000 to $541,000 with a best estimate of $304,000 using figures established from our 3-year experience with PDT. Sensitivity analysis of the net present value for each critical variable was $227,000 per day of reduced intensive care unit length of stay, $180,000 per cost of operating room avoidance, $100,000 per intensive care unit bed cost per day, and $11,000 per additional tracheostomy per year. CONCLUSIONS: There were no significant clinical differences between open and PDT in cardiac surgery patients during the 3-year study period; however, PDT offered significant cost savings.

Cardiac Surgical Procedures↗
PubMed2005

No-clamp technique for valve repair or replacement in patients with a porcelain aorta.

BACKGROUND: Patients requiring valvular heart surgery may have circumferential calcification of the ascending aorta. A variety of creative procedures have been described for managing this "porcelain aorta." We describe a technique based on replacement of the ascending aorta and proximal arch under profound hypothermic circulatory arrest, followed by the valve procedure. METHODS: Twenty-five consecutive patients with a porcelain aorta were referred for heart valve surgery. In every case the aorta was replaced under circulatory arrest before the valve procedure. Postoperative morbidity, mortality, and univariate risk factors for death were calculated. Fisher's exact test defined significant perioperative variables with a p value less than 0.05. RESULTS: Of 25 patients, 23 (92%) survived the surgery to hospital discharge. One patient had a stroke (4%) and 2 patients (8%) required reexploration for bleeding. Risk factors for perioperative death by univariate analysis included age more than 78 years (p < 0.009), cardiopulmonary bypass time longer than 200 minutes (p < 0.0001), reexploration for bleeding (p < 0.02), need for intra-aortic balloon pump support (p < 0.001), and postoperative gastrointestinal complications (p < 0.001). CONCLUSIONS: Valve replacement or repair in the patient with a porcelain aorta can be safely accomplished with a technique based on aortic replacement under circulatory arrest. Elderly patients requiring extensive procedures and prolonged periods on bypass have a substantially increased risk for postoperative complications and death.

Aged↗
PubMed2004

Management strategies for type A dissection complicated by peripheral vascular malperfusion.

BACKGROUND: End-organ malperfusion is a dreaded complication of type A aortic dissections. Different strategies have been proposed to manage this complex cohort of patients. Ideal management includes the rapid restoration of organ perfusion while avoiding catastrophic rupture and tamponade. We present our experience with primary aortic repair as the optimal method of patient management. METHODS: From July 1997 until April 2003, 101 patients underwent dissection repair and were assessed for malperfusion of the central nervous system, renal, visceral or extremity circulation. Patients with coronary artery malperfusion were analyzed separately. Aortic repair was performed expeditiously utilizing femoral bypass, circulatory arrest, and antegrade perfusion after completion of the distal anastomosis. Persistent malperfusion led to additional procedures. In-hospital morbidity, end-organ salvage, and mortality were determined. Chi-square analysis defined variables contributing significantly to outcome. RESULTS: Twenty-three patients presented with malperfusion. The operative mortality for the entire cohort with malperfusion, 4.4% (n = 1), was not greater than those without it, 5.1% (n = 4). Five patients required additional procedures following aortic repair, a majority in patients with persistent extremity ischemia. All deficits resolved except for one patient with spinal ischemia and one with visceral ischemia. Visceral malperfusion was highly lethal with a mortality of 33% (n = 1). All other patients presenting with malperfusion survived to discharge. CONCLUSIONS: Patients with malperfusion in the setting of acute type A dissection should undergo immediate aortic reconstruction as the primary means of reestablishing end-organ perfusion. Early postoperative intervention for persistent deficits leads to a gratifyingly high rate of end-organ salvage.

Acute Disease↗
PubMed2004

Surgical management of thoracic malignancies invading the heart or great vessels.

BACKGROUND: Surgical resection of thoracic malignancies involving either the heart or great vessels is uncommonly performed because of the potential morbidity and mortality for an unknown probability of significant palliation or cure. We reviewed our experience of 10 patients treated surgically, either primarily or as a component of multimodality therapy, to assess feasibility and results. METHODS: A retrospective review of the results in 10 patients who underwent resection of thoracic malignancies that included either great vessel or the heart was conducted. RESULTS: Histologic diagnoses included soft tissue sarcoma (n = 7), squamous cell carcinoma (n = 1), malignant thymoma (n = 1), and mediastinal teratoma (n = 1). Three patients underwent induction chemotherapy. Cardiopulmonary bypass was used in 7 patients. Structures resected included superior vena cava (n = 5), left atrium (n = 4), right atrium (n = 2), descending aorta (n = 1), and main pulmonary artery (n = 1). Concomitant anatomic pulmonary resections were performed in 3 patients. Seven patients had an R0 or R1 resection. There were no perioperative deaths. All symptomatic patients had immediate and sustained palliation of their presenting symptoms. The median length of stay was 6 days (range, 4 to 43 days). Six patients underwent postoperative systemic therapy. The overall median survival was 21.7 months (range, 3.2 to 69 months) and was 33.3 months (range, 3.7 to 69 months) for patients who had an R0 or R1 resection. CONCLUSIONS: Resection of the heart and great vessels involved by thoracic malignancies can be performed with acceptable morbidity and mortality and results in significant palliation and, in some cases, prolonged survival.

Adult↗
PubMed2003

Outcomes of cardiac surgery in nonagenarians: a 10-year experience.

BACKGROUND: With an increasing awareness of health issues and greater emphasis on preventive medicine, the general population is living longer and healthier lives than ever before. Physicians are taking care of older patients, many of whom may require cardiac surgical procedures. Improving cardiopulmonary bypass technology allows for safer procedures with reduced morbidity and mortality even in older patients. METHODS: We have performed a retrospective analysis of 42 consecutive nonagenarian patients who underwent open-heart procedures over a 10-year period (1993 to 2002) at our institution. Their demographic profiles, operative data, perioperative results, and long-term outcomes were recorded and analyzed. RESULTS: Twenty-two women and 20 men with an age range of 90 to 97 years (mean, 91.4 years) had open-heart surgery over the study period. The complication rate was 67% overall, consisting of 7% respiratory (pneumonia, respiratory failure, reintubation), 7% hemorrhagic or embolic (postoperative bleeding, cerebral vascular accident), 12% infectious (wound infection, sepsis), and 31% new arrhythmia (atrial fibrillation, atrial flutter, ventricular tachycardia, ventricular fibrillation). Despite these complication rates, average hospital stay was 17.5 days (median, 11 days), with an intensive care unit stay of 12.0 days (median, 5 days). Thirty-day survival was 95% and survival to discharge was 93% (three deaths total; one cardiac arrest at hospital day 134 and two perioperative deaths; one ventricular arrhythmia, one cerebral vascular accident). The only statistically significant risk factor of mortality was emergency surgery. Currently, 81% are still alive an average of 2.53 years since surgery (range, 0.16 to 7.1 years). CONCLUSIONS: With improving techniques and greater attention to detail, the select nonagenarian can safely undergo cardiac surgery.

Age Factors↗
PubMed2003

Negative fluid displacement: an alternative method to assess patency of arterial line cannulation.

Optimal flow rate with minimal pressure gradient is the goal of arterial cannulation for cardiopulmonary bypass (CPB). Misplacement of the arterial cannula or vascular pathology can lead to hemolysis or intimal damage with subsequent aortic dissection. The risk of dissection with aortic cannulation is low, 0.04-0.2% for ascending aortic cannulation and 0.2-3% for femoral cannulation. However, dissection-related mortality is significant. Common methods for assessing adequacy of arterial cannulation include minimal pressure when injecting 100-mL boluses and the presence of pulsation in the cannula. Using these techniques, misplacement of the cannula can be masked due to the small amount of volume that is transfused during the assessment. Displacement of fluid into a cannula that is in a false lumen or close to the intimal surface may not indicate a misplaced arterial cannula. Negative fluid displacement is an alternative method of evaluating the integrity of arterial cannulation. During retrograde arterial priming (RAP), fluid is drained from the arterial cannula into a collection bag. Absence of fluid return or a flow < 500 mL/minute is indicative of either arterial line occlusion or cannula misplacement. At this point, the arterial cannula can be repositioned prior to instituting CPB. Since using this technique in over 13000 bypass procedures, we have had only one dissection. This one event occurred during partial occlusion clamping of the ascending aorta. With increased use of femoral cannulation for minimally invasive cardiac surgical procedures, this RAP technique can enhance the perfusionist's and the surgeon's ability to safely perform bypass in the presence of higher dissection risk.

Aortic Dissection↗
PubMed2003

Diagnosis and treatment of heparin-induced thrombocytopenia.

Heparin-induced thrombocytopenia (HIT) is a major side effect secondary to the administration of heparin. This syndrome is serious and potentially life threatening. This response is the result of antibodies formed against the platelet factor 4 (PF4)/heparin complex. The incidence of this immune-mediated syndrome has been estimated to be 1-3% of all patients receiving heparin therapy. The occurrence of HIT in patients requiring full anticoagulation for cardiopulmonary bypass (CPB), therefore, presents a serious challenge to the cardiac surgery team. The diagnosis of HIT should be based on both clinical and laboratory evidence. While functional assays, platelet aggregation tests, and the serotonin release assay can be used to support the diagnosis, the negative predictive value of these tests is generally less than 50%. In contrast, although non-functional antibody detection assays are more sensitive, they have a low specificity. HIT can be treated in several ways, including cessation of all heparin and giving an alternative thrombin inhibitor, platelet inhibition followed by heparin infusion, and the use of low molecular weight heparins. In this presentation, the pathology and current diagnostic tests, as well as the successful management of patients with HIT undergoing CPB at New York Presbyterian Hospital, are reviewed.

Anticoagulants↗
PubMed2002

Ruptured descending and thoracoabdominal aortic aneurysms.

BACKGROUND: Advances in end-organ protection have dramatically reduced the incidence of the life-threatening complications associated with the elective repair of thoracoabdominal and descending thoracic aortic aneurysms. However, in the setting of a ruptured thoracic aneurysm, one may not have the luxury of complex end-organ support. We analyzed our experience with ruptured thoracic aneurysms to define morbidity and mortality in the present era. METHODS: One hundred seventy-two patients with thoracoabdominal or descending thoracic aneurysms were operated on between July 1997 and October 2001. Forty presented with either a contained or free rupture. Three techniques were used for aortic reconstruction: clamp and sew, left heart bypass, and hypothermic circulatory arrest. Adjuncts for neurologic and renal support were used when circumstances and anatomy permitted. RESULTS: Seven of 40 patients died in the hospital (17.5%). Four patients died intraoperatively, all of acute myocardial infarction. Five of the seven deaths were in patients who presented in shock. Two patients (5%) experienced paraplegia, 3 (7.5%) had renal failure requiring hemodialysis, 8 (20%) required a tracheostomy, and 6 (15%) had recurrent nerve palsies. There was one stroke (2.6%). Mean diameter of ruptured aneurysms was 8.5 cm. CONCLUSIONS: Ruptured thoracic aneurysms can be repaired with a gratifying rate of salvage. Rapid diagnosis and triage for repair is necessary to avoid progressive deterioration into shock. The incidence of myocardial infarction, and the mortality associated with this event, underscores the need for aggressive cardiac evaluation in the elective thoracic aneurysm patient. The size at rupture also emphasizes the need for earlier referral for elective aneurysm repair.

Adult↗