A prospective randomized trial of endoscopic versus conventional harvesting of the saphenous vein in coronary artery bypass surgery.

OBJECTIVES: Our objectives were (1) to determine whether minimally invasive endoscopic harvesting of the saphenous vein reduces morbidity due to postoperative wound infection and pain with improved cosmetic results and mobilization as compared with the conventional technique and (2) to compare the histologic properties of the saphenous veins harvested conventionally and endoscopically. METHODS: One hundred forty-four patients undergoing coronary artery bypass grafting were randomized to have vein harvesting performed by either the conventional (n = 72) or an endoscopic (n = 72) minimally invasive technique. RESULTS: Vein harvest time (open leg wound time) was significantly reduced in the endoscopic group (27.6 vs 64.4 minutes; P <.0001). The rate of leg wound infection was significantly reduced in the endoscopic group (4.3%) as compared with the conventional group (24.6%), a relative risk reduction of 83% (95% confidence interval: 36%-129%; P =.0006). The majority of infections (84.2%) occurred after hospital discharge. Postoperative leg pain, mobilization, and overall patient satisfaction were also significantly improved in the endoscopic group. Double blinded histologic assessment of harvested vein (n = 28) showed no evidence of any clinically important significant damage to the specimens in either group. CONCLUSIONS: In this prospective randomized trial, endoscopic harvesting of the saphenous vein significantly reduced postoperative leg wound complications, including infection, and improved patient satisfaction as compared with the conventional harvesting technique. There were no significant histologic differences between the conventional and endoscopically harvested saphenous veins.

The cost-effectiveness of routine pathology consultation in knee arthroscopy.

Regulations in Ontario, Canada, as in most provinces and states in North America, require human tissues (with few exceptions) removed at surgery to be sent to a pathology laboratory for examination and report. We hypothesized that this practice is inconsistently followed and that routine pathological consultation is costly and rarely results in a change in treatment for patients undergoing knee arthroscopy. Chiefs of pathology, orthopaedic surgeons, and orthopaedic operating room nurse managers in Ontario hospitals that perform arthroscopic knee surgery were surveyed for compliance. We determined cost using pathology department procedure codes and evaluated effectiveness as the correlation between the postoperative diagnoses of orthopaedic surgeons and pathologists for 1,036 consecutive knee arthroscopy cases. In only one case (0.1%) was it felt that pathology consultation had the potential to significantly alter patient care. The total cost of pathology consultation for the 1,036 cases reviewed was $234,147.00 (mean cost per case, $226.00). Ninety percent of hospitals do not comply with the regulations regarding the processing of these tissues. Poor compliance is justified by the lack of diagnostic value and the need to contain health care costs.

Arteritis and increased intracellular calcium as a possible mechanism for tacrolimus-related cardiac toxicity in a pediatric transplant recipient.

We recently reported partially to wholly reversible hypertrophic cardiomyopathy, including severe hypertrophic obstructive cardiomyopathy, as a side effect in pediatric transplant recipients receiving tacrolimus immunosuppression. This seemed to be dose related. We describe a pediatric patient receiving tacrolimus who died 3 weeks after liver/bowel transplantation. Postmortem findings revealed arteritis of cardiac arteries and extensive calcification of cardiac tissue suggesting a possible mechanism of tacrolimus cardiac toxicity. This is consistent with recent reports of tacrolimus increasing calcium release into the sarcoplasmic reticulum of cardiac and striated muscle.

Atrial flutter: lessons from surgical interventions (musing on atrial flutter mechanism).

We report our experience with seven patients who underwent direct surgical ablation of problematic common flutter. Intraoperative mapping was obtained in four patients. Surgical techniques varied over time. A circular incision of the right atrium was performed in the first patient. Two patients had epicardial cryoablation of the isthmus between the inferior vena cava and the tricuspid valve annulus. Four patients had extensive endocardial cryoablation of the isthmus. There were no immediate postoperative complications. One patient had atrial fibrillation 2 months postoperatively and underwent a corridor operation 1 year later. The other six patients are free of arrhythmias without antiarrhythmic drugs. Surgical ablation confirmed that the common form of atrial flutter is associated with a right atrial macroreentrant circuit. One of our intraoperative endocardial maps suggested that variant reentrant circuits can be associated with variant forms of flutter.

Surgery for supraventricular tachycardia.

1995 is the fifth anniversary of the advent of catheter ablation for the treatment of supraventricular tachycardia. Surgery has established the principles of the interventional approaches: 1) identification of the mechanism; 2) localization of the site of the mechanism; 3) identification of the anatomical arrhythmogenic substrate and its localization using preoperative and intraoperative electrophysiological cardiac mapping; 4) ablation of the arrhythmogenic substrate using "surgical" dissection or excision or various forms of energy to neutralize the substrate: cryoablation, laser, etc. Surgical approaches also established the EP interventions as the first line of therapy because they are curative. Currently, surgery for supraventricular tachycardia is essentially confined to atrial fibrillation, and after attempted catheter ablation for the Wolff-Parkinson-White syndrome. Atrial fibrillation is a complex arrhythmia, commonly associated with structural heart disease. To understand atrial fibrillation, a number of premises should be reviewed: atrial functional anatomy, atrial pathology, atrial fibrillation mechanism (s) and clinical presentation. The role of atrial fibrillation in terms of symptoms, morbidity and mortality is not clear because it is difficult to determine if atrial fibrillation is a symptom, a marker, an autonomous disease albeit it is in most cases an aggravating factor. Surgical rationales for atrial fibrillation are based on three concepts: exclusion, fragmentation and channelling. The Corridor operation was the first used direct surgical approach. The Maze operation and other techniques (fragmentation, spiral) have been reported. All surgical techniques have been reported with good results in terms of sinus node function and exercise tolerance, and to various degrees, in terms of atrial contraction. Currently, there is a trend to combine direct atrial fibrillation surgery with surgery for mitral valve albeit beneficial effects are not documented.

Routine surveillance myocardial biopsies are unnecessary beyond one year after heart transplantation.

BACKGROUND: Myocardial rejection is most apt to occur in the first 90 days after heart transplantation. Nevertheless, surveillance endomyocardial biopsies are often performed on a regular basis, indefinitely. The benefit of this approach to patient management is uncertain. Our objective was to determine the frequency of abnormalities and the influence of a routine annual endomyocardial biopsy on patient management. METHODS: In a consecutive series of 235 transplant recipients who survived 1 year or more, the results of 1123 routine endomyocardial biopsies performed 1 year or more after transplantation were reviewed. The incidence of late rejection, presence of Quilty effect (focal endocardial or myocardial lymphocytic aggregates), and therapeutic reaction to the biopsy result were analyzed. RESULTS: Of 1123 biopsy specimens in 235 patients (1 to 12 years after transplantation), 1115 (99.3%) showed no evidence of significant rejection (grade 0 or 1). Only seven (0.6%) had evidence of rejection grade 2 or worse. Of the seven abnormal biopsy specimens in seven patients, two occurred at 1 year, two at 2 years, and one each at 4, 7, and 8 years. Of these, six were treated for rejection with an increase in the immunosuppressive therapy. One patient was identified as having a symptomatic condition at the time of biopsy. A focal endocardial or myocardial accumulation of lymphocytes (Quilty effect) was present in 311 biopsy specimens (27.6%). Beyond 1 year, 33 patients died, 14 because of graft vascular disease with or without rejection and 19 because of other causes. No deaths were predicted on the basis of a routine surveillance biopsy. CONCLUSIONS: Myocardial rejection is rare beyond 1 year after transplantation. The routine endomyocardial biopsy does not significantly impact patient management beyond 1 year. A selective approach to myocardial biopsies, on the basis of a change in clinical status or immunosuppressive medications, is justified.

Latissimus dorsi dynamic cardiomyoplasty: role of combined ICD implantation.

Latissimus dorsi cardiomyoplasty is a promising surgical therapy in some patients with congestive heart failure. Although the mortality in heart failure patients is attributable primarily to heart failure and ventricular arrhythmias, the mechanism of death after cardiomyoplasty is not well characterized. We describe the clinical course of a patient undergoing cardiomyoplasty and discuss the role of combined use with an implantable cardioverter defibrillator. A 39-year-old man with congestive heart failure due to a massive anterior wall myocardial infarction was evaluated for latissimus dorsi cardiomyoplasty. The patient was in NYHA Functional Class III due to heart failure. He did not have any significant exertional or rest angina. During a Naughton stress test, the patient could exercise for 10 minutes, achieving 4 METS. Pulmonary function study showed a peak V O2 of 22.1 mL/min per kg. Radionuclide angiography demonstrated that the anterior wall was akinetic with a left ventricular ejection fraction of 22%. Cardiac hemodynamic studies suggested moderate pulmonary hypertension, elevated wedge pressure, and suboptimal response to exercise. A Holter recording showed frequent ventricular extrasystoles. Cardiomyoplasty was preferred to heart transplantation because the patient did not have end-stage heart failure. Postoperatively, the patient required low doses of dopamine. He developed recurrent, sustained, and hemodynamically significant episodes of ventricular tachycardia. He was treated with a combination of amiodarone and procainamide. He died 2 days postoperatively with ventricular fibrillation. Ventricular arrhythmias are a major cause of death in patients with heart failure. Latissimus dorsi cardiomyoplasty appears to be a promising but unproven therapy in such patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Non-HLA-linked hemochromatosis in a Chinese woman.

A 55 year-old Chinese woman is described with severe iron overload similar in degree and distribution to that seen in hereditary hemochromatosis in the Caucasian population. Autopsy findings confirmed severe iron overload in the liver, pancreas, skin, heart, and endocrine organs. Hepatic iron concentration was 482 mumol/g with a hepatic iron index of 8.8. There was no history of thalassemia, transfusions, or alcohol abuse. Pedigree analysis revealed two HLA identical brothers that had no clinical or biochemical evidence of iron overload. This case is an unusual example of severe iron overload in a non-Caucasian kindred and may represent a non-HLA-linked form of iron overload.

Chronic rapid atrial pacing. Structural, functional, and electrophysiological characteristics of a new model of sustained atrial fibrillation.

BACKGROUND: Despite the clinical importance of atrial fibrillation (AF), the development of chronic nonvalvular AF models has been difficult. Animal models of sustained AF have been developed primarily in the short-term setting. Recently, models of chronic ventricular myopathy and fibrillation have been developed after several weeks of continuous rapid ventricular pacing. We hypothesized that chronic rapid atrial pacing would lead to atrial myopathy, yielding a reproducible model of sustained AF. METHODS AND RESULTS: Twenty-two halothane-anesthetized mongrel dogs underwent insertion of a transvenous lead at the right atrial appendage that was continuously paced at 400 beats per minute for 6 weeks. Two-dimensional echocardiography was performed in 11 dogs to assess the effects of rapid atrial pacing on atrial size. Atrial vulnerability was defined as the ability to induce sustained repetitive atrial responses during programmed electrical stimulation and was assessed by extrastimulus and burst-pacing techniques. Effective refractory period (ERP) was measured at two endocardial sites in the right atrium. Sustained AF was defined as AF > or = 15 minutes. In animals with sustained AF, 10 quadripolar epicardial electrodes were surgically attached to the right and left atria. The local atrial fibrillatory cycle length (AFCL) was measured in a 20-second window, and the mean AFCL was measured at each site. Marked biatrial enlargement was documented; after 6 weeks of continuous rapid atrial pacing, the left atrium was 7.8 +/- 1 cm2 at baseline versus 11.3 +/- 1 cm2 after pacing, and the right atrium was 4.3 +/- 0.7 cm2 at baseline versus 7.2 +/- 1.3 cm2 after pacing. An increase in atrial area of at least 40% was necessary to induce sustained AF and was strongly correlated with the inducibility of AF (r = .87). Electron microscopy of atrial tissue demonstrated structural changes that were characterized by an increase in mitochondrial size and number and by disruption of the sarcoplasmic reticulum. After 6 weeks of continuous rapid atrial pacing, sustained AF was induced in 18 dogs (82%) and nonsustained AF was induced in 2 dogs (9%). AF occurred spontaneously in 4 dogs (18%). Right atrial ERP, measured at cycle lengths of 400 and 300 milliseconds at baseline, was significantly shortened after pacing, from 150 +/- 8 to 127 +/- 10 milliseconds and from 147 +/- 11 to 123 +/- 12 milliseconds, respectively (P < .001). This finding was highly predictive of inducibility of AF (90%). Increased atrial area (40%) and ERP shortening were highly predictive for the induction of sustained AF (88%). Local epicardial ERP correlated well with local AFCL (R2 = .93). Mean AFCL was significantly shorter in the left atrium (81 +/- 8 milliseconds) compared with the right atrium 94 +/- 9 milliseconds (P < .05). An area in the posterior left atrium was consistently found to have a shorter AFCL (74 +/- 5 milliseconds). Cryoablation of this area was attempted in 11 dogs. In 9 dogs (82%; mean, 9.0 +/- 4.0; range, 5 to 14), AF was terminated and no longer induced after serial cryoablation. CONCLUSIONS: Sustained AF was readily inducible in most dogs (82%) after rapid atrial pacing. This model was consistently associated with biatrial myopathy and marked changes in atrial vulnerability. An area in the posterior left atrium was uniformly shown to have the shortest AFCL. The results of restoration of sinus rhythm and prevention of inducibility of AF after cryoablation of this area of the left atrium suggest that this area may be critical in the maintenance of AF in this model.

Immunological and biological evidence for a stanniocalcin-like hormone in human kidney.

The corpuscles of Stannius are responsible for the synthesis and secretion of stanniocalcin (STC), a glycoprotein hormone that regulates calcium and phosphate homeostasis in fishes through its actions on the gills and kidneys. The corpuscles of Stannius and STC are considered to be an endocrine system that is unique to fishes. In this report, we provide evidence for the existence of STC-like proteins in vertebrates other than fishes, in particular, humans. By using a well-characterized RIA for salmon STC, sera from vertebrates as diverse as sharks and humans contained measurable levels of STC-like immunoreactivity in the concentration range commonly observed in fishes, and all of these sera exhibited parallelism in the assay. By using Western blot analysis, proteins were also identified in human kidney extracts that shared several properties with the fish hormone in addition to their cross-reactivity with salmon STC antiserum. The same antiserum was used to identify a discrete population of cells in human kidney tubules that could be the source of serum immunoreactivity. Human kidney extracts containing the STC-immunoreactive proteins also had STC-related effects when injected into fishes. Collectively, the data suggest that STC may be more widespread among the vertebrates than is currently accepted.

Intraoperative mapping is not necessary for VT surgery.

Surgical ablation of ventricular tachycardia is generally guided by the results of pre- and intraoperative cardiac mapping. However, in certain situations intraoperative cardiac mapping may not be possible and, therefore, surgery has to be based on information obtained preoperatively. This raises the question whether intraoperative mapping is necessary for the success of this approach. We describe our experience with encircling endocardial cryoablation for ischemic VT and examine the contribution of intraoperative mapping for this procedure. Thirty-three patients with inducible VT refractory to medical therapy and a well defined anatomic scar were considered for surgery. All patients underwent baseline electrophysiology study and intraoperative mapping was attempted during normothermic cardiopulmonary bypass. In 14 patients, VT was inducible intraoperatively (Group 1) and surgical ablation was guided by this information, whereas in 19 patients, VT could not be mapped for various reasons (Group 2). Reasons for failure to obtain intraoperative map included noninducibility (3), nonsustained VT (8), polymorphic VT (4), VF (3), and incessant VT with hemodynamic collapse and cardiac arrest (1). The two groups did not differ with respect to age, location of myocardial infarction, or preoperative left ventricular ejection fraction. The operative procedures were similar in the two groups with respect to aortic cross clamp time, cardiopulmonary bypass time, number of cryoablation lesions, concomitant revascularization, aneurysmectomy, and ICD implantation. Encircling endocardial cryoablation was performed in 32 patients and one patient underwent partial right ventricular free wall disconnection (RV infarct). Thirteen patients underwent concomitant coronary artery bypass grafting (5 in Group 1 and 8 in group 2). One patient had prophylactic ICD patches (Group 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Encircling endocardial cryoablation for ventricular tachycardia after myocardial infarction: experience with 33 patients.

Encircling endocardial cryoablation, consisting of circumferential cryoablation of the infarct scar, can be curative in selected patients with ventricular tachycardia (VT). We describe our experience with and long-term outcome in 33 patients undergoing this procedure. The interval between myocardial infarction and the onset of tachycardia varied from 2 weeks to 22 years (mean 38 +/- 63 months and median 3 months). All patients had a left ventricular aneurysm (anterior in 20, posterior in 12, and lateral in 1) and significant coronary artery disease. Fourteen patients had clinical evidence of heart failure preoperatively. Twenty-eight patients had sustained monomorphic VT (incessant in 3); 3 had polymorphic or nonsustained tachycardia; 2 had primary ventricular fibrillation; and 1 had associated Wolff-Parkinson-White syndrome. Surgery was undertaken after failed drug therapy and consideration of left ventricular anatomy and function. At surgery, 32 patients had encircling endocardial cryoablation, and 1 patient had partial right ventricular free-wall disconnection (right ventricular infarct). Thirteen patients underwent concomitant coronary artery bypass grafting. An implantable cardioverter defibrillator (ICD) was implanted in 2 patients and prophylactic ICD patches in 1. One patient died postoperatively; 3 had recurrent VT perioperatively; 1 was treated with amiodarone; and 2 had ICD implantation. During long-term follow-up (mean 5 years), all patients who were free of tachycardia at discharge remained alive and free of arrhythmias or syncope. The patient receiving amiodarone sustained a cardiac arrest subsequently and received an ICD implant. One patient with an ICD continued to receive appropriate shocks frequently and died 2 years after surgery. Nine patients had congestive heart failure postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Operation for the Wolff-Parkinson-White syndrome in the catheter ablation era.

Catheter ablation has greatly altered surgical referral patterns for the Wolff-Parkinson-White syndrome. We describe 51 patients (aged 9 to 63 years; 35 male, 16 female) referred for operation from our institution and elsewhere between August 1990 and August 1993, coincident with the inception of our ablation program. During the same period, 375 patients with problematic Wolff-Parkinson-White syndrome had ablation procedures. Operation was the initial therapy in 26 patients, due to physician preference in 23 and the need for a concomitant cardiac operation in 3. Operation was related to ablation failure in 22 patients and was urgent in 3 patients. Previous ablation was not associated with added surgical difficulties, and all pathways were ablated intraoperatively on the first attempt using the epicardial approach. Visible epicardial lesions were observed in 8 patients at the site of the accessory pathway. In 2 patients, the lesions were remote to the atrioventricular ring. There was a striking significant increase in proportion of right free wall pathways after attempted ablation (27% versus 8%) as compared with the preablation era. We conclude that previous attempted ablation does not impair efficacy and safety of operative therapy. Operation remains a useful alternative for ablation failure and as a back-up for acute complications.

Cardiac and sympathetic effects of middle cerebral artery occlusion in the spontaneously hypertensive rat.

Acute increases in sympathetic activity, plasma catecholamine concentrations and myocardial damage, occur following middle cerebral artery occlusion (MCAO) in Wistar rats. Hypertension is a major risk factor for stroke. The autonomic responses to MCAO in the spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats were therefore investigated. Arterial pressure (AP), heart rate (HR), renal sympathetic nerve discharge (SND), plasma catecholamines and ECG were measured in 16 SHR and 16 WKY male urethane-anesthetized rats, which were subjected to either MCAO or sham MCAO. Cerebral infarct size did not differ between SHR and WKY rats, as shown by tetrazolium staining. Initial AP was significantly higher in SHR (96 +/- 4 mmHg) than in WKY (70 +/- 1 mmHg; P < 0.05). No significant differences in initial HR or plasma catecholamine levels were observed between SHR and WKY. By 6 hours after MCAO, AP, SND and plasma epinephrine in SHR decreased significantly, while HR showed a significant increase. SND and plasma catecholamines in the WKY showed increases that did not reach significant levels following MCAO. The QT interval of the ECG was significantly prolonged in the WKY MCAO rats, which also had a higher frequency of cardiac myocytolysis than the other groups. Unlike the increases in autonomic variables following MCAO in Wistar rats, SHR exhibit significant decreases in SND and AP, while WKY show slight, but non-significant increases. These differences in the autonomic reaction to MCAO may reflect genetic differences in the response to cerebral ischemia.

Asymmetry of sympathetic consequences of experimental stroke.

Asymmetries of sympathetic regulation at the level of the inferior cervical ganglia have long been recognized. Lateralization of autonomic representation may also occur in the brain, since inactivation of the left and right hemispheres by intracarotid amobarbital produces an increase and decrease in heart rate, respectively. However, this conclusion has remained tentative, since the differential effect of lateralized brain lesions on sympathetic activity has not been studied systematically. Forty-eight urethan-anesthetized Wistar rats were divided into three groups: a group given left middle cerebral artery occlusion, and a group given sham operation. Heart rate, mean arterial blood pressure, renal sympathetic nerve discharge, and electrocardiogram were monitored throughout the 4-hour experiments. Plasma epinephrine and norepinephrine levels were measured at baseline and 1 and 4 hours after occlusion or sham occlusion. The mean arterial pressure decreased in the group given sham operation and to lesser extent in the group given left middle cerebral artery occlusion. By contrast, mean arterial pressure did not fall in the group given right middle cerebral artery occlusion and at 4 hours was significantly higher than control values in the sham-occluded rats. Renal sympathetic nerve discharge was decreased in the sham-occluded group, increased significantly from 20 minutes to 2 hours in the group given left middle cerebral artery occlusion, and increased from about 20 minutes to the end of the experiment in the group given right middle cerebral artery occlusion. The plasma norepinephrine level was significantly elevated at 1 hour (93%) and 4 hours (44%) only in the group given right middle cerebral artery occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)

A permanent transvenous lead system for an implantable pacemaker cardioverter-defibrillator. Nonthoracotomy approach to implantation.

A transvenous lead system for implantable defibrillators would obviate a surgical thoracotomy and reduce the morbidity and mortality associated with implantation. We evaluated the clinical performance of a new nonthoracotomy lead system that included a defibrillation lead in the coronary sinus. At the time of defibrillator implantation, transvenous defibrillation leads were inserted percutaneously through the left subclavian vein into the right ventricular apex (RVA), superior vena cava (SVC), and distal coronary sinus (CS) under fluoroscopic guidance. A subcutaneous patch electrode (SQ) was also available if required. The first single- or dual-pathway electrode configuration that successfully terminated three of four ventricular fibrillation episodes using 18 J or less was implanted. Eleven men and three women aged 39-77 years (60.0 +/- 10.1 years) with left ventricular ejection fraction ranging from 16% to 63% (33.4 +/- 13.1%) were evaluated. Nine presented with ventricular tachycardia, three had ventricular fibrillation, and two had both. A totally transvenous lead system (RVA/CS/SVC) was implanted in seven patients (50%) with a mean defibrillation threshold of 15.6 +/- 2.9 J (10-18 J). Four patients received a partial transvenous lead system (RVA/CS/SQ). An effective nonthoracotomy lead system was not found in three patients; they received epicardial electrodes. After cumulative follow-up of 73 patient-months, nine patients remain alive and free of problems related to the implanted nonthoracotomy leads. One patient died of respiratory failure 3 months after defibrillator implant, and the leads from another patient were removed at 9 months because of bacterial infection. A transvenous lead system that includes a defibrillation lead in the coronary sinus is a safe, reliable, and, at least in the short term, effective nonthoracotomy approach for automatic defibrillator implantation.