Thoracoscopic internal mammary artery harvest for MICABG using the Harmonic Scalpel.

BACKGROUND: Thoracoscopic internal mammary artery (IMA) harvest is technically demanding, particularly on the left side. We have devised a Harmonic Scalpel (Ethicon Endo-Surgery, Cincinnati, OH) technique to facilitate this procedure, and describe our clinical experience here. METHODS: The Harmonic Scalpel functions with ultrasonic energy, producing less smoke and lower heat than regular electrocautery. A total of 27 (22 left and 5 right) pedicles of the IMA in 23 patients were harvested from the upper margin of the first rib or higher to the lower margin of the fifth rib thoracoscopically using the Harmonic Scalpel with a hook blade. RESULTS: In each case, the IMA harvest was completed thoracoscopically with only the Harmonic Scalpel, decreasing instrument transfers. Each vascular branch was coagulated without charring and was transected with excellent hemostasis. Smokeless views were provided. In the first 17 harvests, Doppler studies 3 months after the procedures demonstrated patent IMAs to the coronary circulation. CONCLUSIONS: The Harmonic Scalpel facilitates thoracoscopic IMA harvest and is expected to minimize hyperthermic damage of the IMA.

When to start cholesterol-lowering therapy in patients with coronary heart disease. A statement for healthcare professionals from the American Heart Association Task Force on Risk Reduction.

At present a large number of patients with atherosclerotic disease are not receiving aggressive cholesterol-lowering therapy. Consequently they are being deprived of a cost-effective, risk-reducing treatment. Every physician who treats patients with clinical atherosclerotic disease should become fully informed about the results of cholesterol-lowering trials in patients at high risk. All physicians who care for high-risk patients should take responsibility for cholesterol management, including primary care physicians and cardiovascular specialists. Highly effective and generally safe drugs for cholesterol lowering are available. The benefits of therapy for reducing recurrent CHD and prolonging life are considerable. There is no justification for unduly delaying institution of therapy for the majority of patients. The many advantages of nonpharmaceutical therapy call for its use in almost all patients, but drug treatment should not be postponed if the target for LDL cholesterol lowering (< or = 100 mg/dL) is unlikely to be achieved in the near term by a nonpharmaceutical approach alone. The view that patients with CHD or other forms of atherosclerotic disease do not receive substantial clinical benefits from aggressive cholesterol-lowering therapy is no longer warranted. Intensive cholesterol reduction, initiated immediately, has the potential to significantly reduce both morbidity and mortality. Cholesterol-lowering therapy thus should become a routine part of clinical management to reduce risk of future coronary events and to prolong life in patients with CHD or other forms of atherosclerotic disease.

Can atherosclerotic coronary arteries vasodilate? An intraoperative high-frequency epicardial echocardiographic study.

Our purpose was to evaluate the vasodilating responses of atherosclerotic coronary arteries using intraoperative high-frequency (12 MHz) epicardial echocardiography. We obtained continuous high-frequency epicardial echocardiographic recordings during surgery, and determined cross-sectional lumen area from 17 coronary arterial segments (12 patients). Nitroglycerin (100 to 400 micrograms/min) was administered intravenously to reduce mean (+/- SEM) arterial pressure 14 +/- 1.8 mm Hg. The cross-sectional arterial images were classified using 3 different parameters: arterial lumen area, percentage of the arterial wall circumference that was atherosclerotic (wall thickness > 0.7 mm), and presence of an eccentrically shaped arterial lumen (maximal/minimal luminal diameter > 1.5). Nine arterial segments had small (< 5.0 mm2) arterial lumens (1.7 +/- 0.40 mm2 [+/- SEM; range 0.6 to 3.9]). With nitroglycerin, the luminal area increased 0.8 +/- 0.28 mm2 (range 0 to 2.5), and 39 +/- 12.1% (range 0 to 117). The remaining 8 segments had larger (> 5.0 mm2) lumens (8.7 +/- 0.91 mm2 [range 5.0 to 11.9]). With nitroglycerin the luminal area increased 4.3 +/- 1.11 mm2 (range 1.4 to 11.4), and 51 +/- 10.2% (range 16 to 96). Seven arterial segments had eccentric lumens; mean maximal/minimal ratio was 1.8 +/- 0.08 (range 1.6 to 2.0). The area increased 39 +/- 7.3% (range 16 to 71) with nitroglycerin. In the 10 concentrically shaped lumens (maximal/minimal lumen diameters 1.3 +/- 0.04 [range 1.1 to 1.5]), nitroglycerin increased luminal area by 48 +/- 12.6% (range 0 to 117) (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

The risk factors of median sternotomy infection: a current review.

Sternal sepsis following median sternotomy is an infrequent yet devastating complication of cardiac surgery, leading to prolonged hospitalization, increased hospital expense, and a high associated morbidity and mortality. The development of sternotomy infection is multifactorial. Numerous prospective and retrospective studies have pointed to a multitude of clinical and perioperative variables as being causative, with as many other studies presenting evidence of the contrary. This has led to confusion about which clinical variables should be modified so as to minimize the individual patient's risk for developing this severe complication. Other less obvious factors also come into play. Malnutrition, whether overt or subclinical, is not uncommon in cardiac patients. Immune competency is affected by operative trauma, as well as a variety of perioperative factors including underlying nutritional status, transfusion, cardiopulmonary bypass, and anesthesia. This creates a complex milieu for the development of postoperative infection. In this review, the multiple risk factors of median sternotomy infection are studied and treatment options briefly discussed.

Coronary arterial remodeling studied by high-frequency epicardial echocardiography: an early compensatory mechanism in patients with obstructive coronary atherosclerosis.

Coronary arterial remodeling is a compensatory mechanism that may limit the adverse effects of coronary obstructive lesions by expansion of the entire vascular segment. To determine if this compensatory anatomic change occurs in patients, high-frequency epicardial echocardiography using a 12 MHz transducer was performed during open heart surgery in 33 patients (10 with normal coronary arteries undergoing valvular surgery and 23 with coronary atherosclerosis). From stop-frame videotape high-frequency epicardial echocardiographic images, cross-sectional measurements of luminal area and total arterial area (lumen, intima, media and dense adventitia) were made in the patients with atherosclerosis at the site of arterial lesions and from the most proximal portion of the same artery. Remodeling was defined as enlargement of the total arterial area. In normal arteries measurements were made from proximal and midarterial locations. In the patients with normal coronary arteries, total arterial area, as determined by high-frequency echocardiography, decreased from the proximal site to the midportion of the artery (from 10.4 +/- 0.9 to 8.4 +/- 1.0 mm2, p less than 0.05); luminal area also decreased (from 6.0 +/- 0.6 to 4.5 +/- 0.7 mm2, p less than 0.05). In patients with coronary arterial lesions, luminal area also decreased from the proximal site to the arterial lesion site (from 5.3 +/- 0.6 to 2.3 +/- 0.3 mm2, p less than 0.05), but total arterial area increased (from 11.6 +/- 1.0 to 13.0 +/- 1.0 mm2, p less than 0.05). Of the 25 coronary arteries evaluated, only 4 had angiographic evidence of coronary collateral formation. These data indicate that coronary arterial remodeling is an important compensatory mechanism in obstructive coronary disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Sternotomy infection: poor prediction by acute phase response and delayed hypersensitivity.

Two hundred twenty-one consecutive adult cardiac surgical patients were examined prospectively for nutritional protein state, acute phase protein response, and delayed hypersensitivity reaction in an attempt to identify patients at high risk for the development of sternal wound infection, which occurred in 6 patients (2.7%). There was no significant correlation between preoperative nutritional protein concentrations (retinol-binding protein, prealbumin, and transferrin) and acute phase protein levels (C-reactive protein, alpha 1-acid glycoprotein, and complements B and C3), nor a statistically significant relationship between nutritional state or acute phase protein response and the development of sternal infection. Preoperative complement C3 levels were elevated, however, in 80.0% of those in whom sternal infections developed compared with 30.6% of those with well-healed wounds. Similarly, postoperative concentrations of alpha 1-acid glycoprotein were elevated in 80.0% of those in whom sternal infections developed compared with 28.6% of those with well-healed wounds. There was no correlation between delayed hypersensitivity and the risk of sternal infection, nor between preoperative nutritional protein and acute phase protein values. Seventy-three percent of patients were anergic on postoperative day 2. Stepwise logistic regression showed that age, body weight, preoperative intensive care unit stay, repeat median sternotomy, internal mammary artery grafting, postoperative hemorrhage, and postoperative cardiac arrest correlated with the development of sternal infection, whereas transfusion requirement, reexploration for bleeding, and the operation performed did not. We conclude that routine delayed hypersensitivity testing is of no value in predicting high-risk cardiac surgical patients when the anergy battery is placed on the preoperative day. Although statistically insignificant, possibly due to the small number of patients in whom sternal infection developed in this study (type II error), a larger study might find preoperative complement C3 and post-operative alpha 1-acid glycoprotein levels to be predictive of patients at risk for the development of sternal wound infection. The final logistic model for the predicted risk 2%) of sternal wound infection is: PREDSWC = exp(EQ)/1 + exp(EQ) where EQ = (0.38 x age) + (0.24 x weight) + (5.42 x preop ICU) + (4.39 x redo) + (7.14 x IMA) + (4.49 x hemorrhage) + (8.81 x arrest) - 62.72, and where preop ICU, redo, hemorrhage, and arrest are defined as yes (1) or no (0), IMA-is defined as 0, 1, or 2, age is in years, and weight is in kilograms.

Videodensitometric analysis of coronary stenoses. In vivo geometric and physiologic validation in humans.

Assessment of the severity of coronary stenoses on arteriograms conventionally is based on subjective estimates of percent luminal diameter narrowing. However, in studies in patients with multivessel coronary artery disease, we have found a poor correlation between percent stenosis and the physiologic significance of an individual coronary obstruction. The purpose of this study was to determine whether computerized videodensitometry would allow estimation of coronary luminal area and therefore prediction of the physiologic significance of individual coronary stenoses in humans. Videodensitometry was used to define the minimal luminal area of 15 left anterior descending, 15 circumflex, and 15 right coronary artery segments in 43 patients. Computer-assisted quantitative coronary arteriography (method of Brown et al) was used to determine the minimal luminal cross-sectional area of these same segments. In each arterial segment, coronary vasodilator reserve was assessed using intraoperative (n = 18 segments) or intracoronary (n = 27 segments) Doppler measurements of coronary vasodilator reserve. Videodensitometric estimates of coronary luminal area correlated well with minimal luminal area defined using the independent geometric technique of quantitative coronary arteriography (r = 0.82, y = 0.97 X + 0.71, SEE = 1.83 mm2, n = 45) and with lesion physiologic significance as defined by studies of the peak-to-resting velocity ratio (r = 0.71, 0.92, and 0.74 for the left anterior descending, circumflex, and right coronary arteries, respectively). Thus, videodensitometry is a promising method that may supplement geometric approaches to quantitative analysis of coronary arteriograms in humans.