Takashi Maseki

Results of omental flap transposition for deep sternal wound infection after cardiovascular surgery.

OBJECTIVE Our experience with omental flap transposition in the treatment of deep sternal wound infections is reviewed here with an emphasis on efficacy, risk factors for in-hospital mortality rates, and long-term results. SUMMARY BACKGROUND DATA Even with improvements in muscle and omental flap transposition, the timing of closure and the surgical strategy are controversial. METHODS Forty-four consecutive patients with deep sternal wound infections were treated using the omental flap transposition from 1985 through 1994. The strategies included debridement with delayed omental flap transposition or single-stage management, which consisted of debridement of the sternal wound and omental flap transposition. Methicillin-resistant Staphylococcus aureus was cultured from more than 50% of the wounds. A logistic regression analysis was used to identify the predictors of in-hospital death after omental flap transposition. RESULTS There were seven (16%) in-hospital deaths. Univariate analysis demonstrated that hemodialysis and ventilatory support at the time of omental flap transposition were significantly associated with in-hospital mortality rates (p = 0.0023 and p = 0.0075, respectively). Thirty-seven patients whose wounds healed well were discharged from the hospital. Two patients with cultures positive for methicillin-resistant Staphylococcus aureus had recurrent sternal infections. Patients without positive methicillin-resistant Staphylococcus aureus cultures had good long-term results after reconstructive surgery. CONCLUSIONS Transposition of an omental flap is a reliable option in the treatment of deep sternal wound infections, unless the patients require ventilatory support or hemodialysis at the time of transposition.

Clinical application of total body retrograde perfusion to operation for aortic dissection

The use of profound hypothermia and total circulatory arrest in the surgical treatment of aortic dissection has previously been reported. However, the safe period of prolonged circulatory arrest with hypothermia remains controversial. We have developed a technique of hypothermic total body retrograde perfusion to achieve systemic organ protection: cerebral protection by continuous retrograde perfusion through the superior vena cava, myocardial protection by coronary sinus infusion, and abdominal visceral organ perfusion by continuous retrograde perfusion through the inferior vena cava. Our technique yields a relatively bloodless operating field and avoids hypoperfusion of vital organs through a false lumen.

Comparative clinical study between retrograde cerebral perfusion and selective cerebral perfusion in surgery for acute type A aortic dissection

OBJECTIVE Selection of a brain protection method is a primary concern for aortic arch surgery. We performed a retrospective study to compare the respective advantages and disadvantages of retrograde cerebral perfusion (RCP) and selective cerebral perfusion (SCP) in patients who underwent surgery for acute type A aortic dissection. METHODS The study reviewed 166 patients who underwent surgery at Nagoya University or its eight branch hospitals between January 1990 and August 1996. There were 91 patients who received SCP and 75 patients who underwent RCP. Results for these two groups were compared. RESULTS There were no significant differences in age, gender, Marfan syndrome rate, DeBakey classification, or emergency operation rate. Rates of various preoperative complications were similar except for aortic valve regurgitation. Arch replacement was performed more often in SCP than in RCP patients (49% vs. 27%, P = 0.0028). There were no significant differences between groups in cardiac ischemic time or visceral organ ischemic time. However, RCP group showed shorter cardio-pulmonary bypass time (297+/-99 vs. 269+/-112 min, P = 0.013) and lower the lowest core temperature (21.6+/-3.1 degrees C vs. 18.7+/-2.1 degrees C, P = 0.0001). SCP duration was longer than RCP duration (103+/-56 vs. 54+/-24 min, P < 0.0001). Despite these differences, RCP patients were not significantly different from SCP patients with regard to any postoperative complication, neurological dysfunction (16 vs. 19%), or operative mortality (all deaths within the hospitalization; 24 vs. 21%). Regarding neurologic dysfunction, there were six cases of coma, six of motor paralysis, two of paraplegia and one of visual loss among SCP patients, and eight cases of coma, three of motor paralysis, and three of convulsion in the RCP group. The incidence of motor paralysis was higher in the SCP group, while the incidence of coma was higher in the RCP group. CONCLUSIONS RCP can be performed without clamping or cannulation of the cervical arteries, which is an advantage in reducing the chances of arterial injury or cerebral embolization. RCP is comparable to SCP in terms of clinical outcome.

The effects of using a leukocyte removal filter during cold blood cardioplegia

During myocardial ischemia, neutrophils and platelets exert negative effects on the myocardium. In this study, we used a leukocyte removal filter during cardioplegia, and investigated its effect on myocardial damage during reperfusion by measuring the plasma levels of granulocyte components, platelet components, and cardiac enzymes [creatinine phosphokinase (CK) and creatinine phosphokinase myocardial band (CK-MB)] in 24 patients who underwent cardiopulmonary bypass. The patients were divided into two groups of 12 according to whether or not a filter was placed in the cardioplegic route. Blood samples were drawn directly from the coronary sinus before aortic cross clamping, and at 1, 5, and 15 min after declamping. Group F, which had the filter, showed better cardiac enzyme and lipid peroxidation results than group N, which did not. The results of this study suggest that the application of a filter during cold blood cardioplegia may reduce myocardial damage.

A new device for exposing the circumflex coronary artery

We have devised a new retractor for use in coronary artery bypass grafting that is made from three woven Teflon tapes. This method allows sufficient counterclockwise rotation of the heart, provides excellent exposure of the posterior and inferior coronary artery systems, and creates a horizontal surgical plane for the circumflex anastomosis.

Effects of proximal ventricular septal pacing on hemodynamics and ventricular activation.

Recently the use of alternate site pacing to improve cardiac function in patients with bradyarrhythmias has increased. In the present study, hemodynamics of right ventricular septal pacing were studied in seven dogs. A bipolar screw‐in lead and endocardial lead were placed in the proximal right ventricular septum and right ventricular apex, respectively. The right ventricle was paced from each site. A conductance catheter and Millar catheter were inserted into the left ventricle to determine the left ventricular pressure and the pressure–volume loop. Cardiac output was measured using the thermodilution method. In five of the seven dogs, ventricular activation was documented by isochronal epicardial activation mapping during each pacing mode. Mean arterial pressure and cardiac output during septal pacing were significantly higher than during apical pacing (110 ± 17 mmHg vs 100 ± 18 mmHg; 1.00 ± 0.39 L/min vs 0.89 ± 0.33 L/min). The positive dp/dt during septal pacing was significantly higher than during apical pacing (2137 ± 535 mmHg/s vs 1911 ± 404 mmHg/s). End‐systolic elastance during septal pacing was significantly higher compared to apical pacing (13.1 ± 0.3 mmHg/mL vs 8.9 ± 4.0 mmHg/mL). The ventricular activation time during septal pacing was significantly shorter than during apical pacing. The epicardial maps generated during septal pacing were similar to those from atrial pacing. We conclude that hemodynamics and interventricular conduction are less disturbed by proximal right ventricular septal pacing than apical pacing in dogs with normal hearts.

Resection of aortic aneurysms without aortic clamp technique with the aid of hypothermic total body retrograde perfusion

Aneurysms involving either the aortic arch or the proximal descending thoracic aorta in five patients were resected with the aid of profound hypothermic total body retrograde perfusion. Traditional surgical management of the aortic arch and the descending thoracic aorta necessitates clamping of the aorta. However, this technique may be associated with rupture or atheroembolism. Rupture occurring at the clamping site may be difficult to repair. Atheroembolism to the brain compromises the neurologic system, and multiple organ embolism is associated with disseminated intravascular coagulopathy. Atheroembolism in cardiovascular surgery has become increasingly prevalent. It is necessary to prevent clamp injuries and to preserve the function of the vital organs, such as the brain, heart, and liver, during aortic reconstruction. We applied a total body retrograde perfusion technique to operations for aortic aneurysms. Total body retrograde perfusion consists of cerebral protection by continuous perfusion through the superior vena cava, intermittent retrograde coronary perfusion through the coronary sinus, and continuous abdominal visceral perfusion through the inferior vena cava. It can yield a relatively bloodless operating field without the need for aortic clamping. We believe this new adjunct offers excellent results in the surgical treatment of aneurysms of the aortic arch or adjacent structures.

Successful repair of tricuspid regurgitation 46 years after causal blunt trauma.

Tricuspid regurgitation arising from chest trauma 46 years earlier was successfully corrected by valve reconstruction in a 67-year-old man. As the merits of valve repair are well established, it can be advocated for traumatic tricuspid regurgitation, regardless of the time from the causal injury.

Pharmacological properties of contraction caused by sodium removal in muscle strips isolated from canine coronary artery

Contractions produced by Na+ removal were studied in muscle strips isolated from canine coronary artery. In the presence of 20 mM K+ and 0.5 mM Ca2+, rapid contractions were observed repeatedly on complete replacement of NaCl with sucrose. This contraction in the absence of Na+ (0-Na) was not affected by phentolamine but was strongly inhibited by verapamil. Ouabain slowly potentiated the O-Na contraction and markedly reduced the inhibition due to verapamil. The O-Na contraction was dependent on external Ca2+ both with and without ouabain. Bepridil had effects very similar to those of verapamil. Amiloride and excess Mg2+ reduced the O-Na contraction and the degree of their inhibition was similar after ouabain treatment. The decrease in verapamil susceptibility could suggest that the O-Na contraction has verapamil-sensitive and -insensitive components. The former is probably due to Ca2+ influx through voltage-dependent channels and the latter to Ca2+ influx through an Na(+)-Ca2+ exchange process. Ouabain is considered to increase the contribution of Na(+)-Ca2+ exchange to the O-Na contraction. Mg2+ may inhibit both verapamil-sensitive and -insensitive pathways. Amiloride probably exerts its inhibitory effect on the contractile machinery.

Effects of sodium and temperature on tension in isolated canine coronary artery.

The effects of sodium and temperature on tension of isolated canine coronary arterial strips were studied.In 20 mEq ·l−1 K solution, the strength of tension was inversely related to the Na concentration. At 37°C, the tension was significantly increased at 70 mEq ·l−1 Na and below. The tension was gradually suppressed by lowering of the temperature from 37°C to 10°C. At 10°C, tension did not developed significantly at Na concentrations between 127 mEq ·l−1 and 12 mEq ·l−1.It was concluded that the decrease in Na concentrations increased the tension of the canine coronary artery and the lowering of temperature supressed the tension inducted by the decrease in Na concentrations.