Eugene A. Hessel

Experience with surgical management of primary infective endocarditis: A collected review of 139 patients

Abstract One hundred thirty-nine patients with primary infective endocarditis who under-went open-heart surgery are analyzed; of these, 24 patients were operated upon at the University of Washington while the rest have been collected from the English literature. One hundred five patients were operated during the active stage and 34 patients in the healed stage. Seventy patients had pre-existent cardiac lesions before the onset of endocarditis. As a group, Streptococcus was the commonest infective organism followed by Staphylococcus. Congestive heart failure alone or with other conditions was the indication for surgery in 96 per cent of patients. Left-heart valves were involved in 135 patients, the aortic valve being the commonest site of infection. Prosthetic valve replacement alone or along with other procedures was done in 113 patients; in the remaining patients reconstructive procedures or homograft valve replacement was done. Over-all early and late mortality rates in the entire series were 25 and 8.6 per cent, respectively. The early mortality rate in the active stage was about 26.6 per cent while in the healed stage it was 11.7 per cent. Of 130 patients who left the operating room, 32 were reported to develop murmurs of regurgitation; of these 32 patients, 3 died of congestive heart failure and/or septicemia, 9 were reoperated upon, while the rest are stable. Two patients had residual infection with the original organism while an-other 2 patients developed reinfection with a new organism. Hemodynamic status is the most important determinant of timing of the operation in this disease. Once congestive heart failure starts due to tear or perforation of a leaflet during the course of active endocarditis, particularly of the aortic valve, surgery should be undertaken at an early date. It is suggested that an aggressive attitude with regard to early surgical intervention in these patients should further reduce the early mortality rate.

Platelet kinetics during deep hypothermia

Abstract The effects of surface-induced deep hypothermia (20°C) on platelets in terms of their disappearance and location during cooling, recovery with rewarming, and subsequent survival were studied in splenectomized dogs utilizing 51Chromium-tagged autologous platelets. The curves for platelet counts and 51Cr activity were similar with both falling to about 10% of control value at 20°C and both returning to control levels within 1 hr of rewarming. No important differences were observed in the platelet count curves in groups of animals with or without a spleen, with or without 1 2 hr of circulatory arrest, and with or without administration of low molecular weight dextran. The mean platelet survival after hypothermia was somewhat longer (4.9 days) than in normothermic control dogs (4.2 days). The site of hypothermic sequestration was determined by counting 51Cr activity in various organs in animals sacrificed at 20°C; virtually all of the sequestered platelets were found in the liver. This was verified by electron micrographs of the liver. The results indicate that the thrombocytopenia of surface-induced deep hypothermia is due to completely reversible temporary sequestration of platelets in the liver and that the mean survival of platelets exposed to this procedure is not shortened.

Correction of Total Anomalous Pulmonary Venous Drainage in Infancy Utilizing Deep Hypothermia with Total Circulatory Arrest

Four critically ill infants aged 3, 5, 5, and 13 months; weighing 3.7, 4.6, 5.3, and 6.5 kg, respectively; with total anomalous pulmonary venous drainage, underwent complete correction of their lesions with the utilization of surface-induced deep hypothermia. Although this series is small, we are not aware of any other consecutive series in this age group with a comparable mortality rate. Rectal temperatures of 17.5 to 20.2 C were utilized, with periods of cardiac arrest and total circulatory interruption of 32 to 41 minutes. Important aspects of the technique are surface cooling, deep ether anesthesia, intravenous low-molecular-weight dextran, induced respiratory alkalosis during cooling, and electrical pacing during resuscitation. This method works well in the infant, in contrast with perfusion techniques in which surgical mortality is excessively high.

Determination of cardiac output by thermodilution during hypothermia

The thermodilution method for estimating cardiac output was compared with the electromagnetic flowmeter technique in 10 mongrel dogs at normothermia and during surface-induced deep hypothermia. Thermodilution curves obtained during cooling or rewarming must be corrected for the baseline drift caused by changing core temperature. At normothermia, the correlation coefficient between the two methods was 0.96 and the reproducibility of the thermodilution technique was 5 percent. Comparable correlation was present during hypothermia. Curves corrected for baseline drift resulted in significantly different output values from those derived from uncorrected curves (p < 0.05). The thermodilution method is valid at low body temperatures. Clinical confirmation of these results, particularly during open heart surgery in infants, is warranted.

Open Heart Surgery in Infective Endocarditis

Fourteen patients with bacterial endocarditis had open heart surgery. Thirteen were operated upon because of congestive heart failure, and in one the indication for surgery was persistent infection. The aortic valve alone was involved in six patients; two patients had both aortic and mitral valve endocarditis. Five patients had infection of the mitral valve, and one patient had tricuspid valve involvement. All the patients received preoperative antibiotics for a variable period.Ten patients left the hospital and four died in the hospital. Of the 10 patients discharged, one died 9 months later of congestive heart failure. Seven patients developed valvular leaks either through the suture line or the homograft, and two deaths resulted. Nine patients are alive and in good functional status. Antibiotics were given for 5 to 10 days postoperatively; one patient, however, received antibiotics for 49 days.Early open heart surgery is recommended in bacterial endocarditis if heart failure is progressive. Shorter postoperative antibiotic therapy is proposed once the source of residual infection is removed.

Repair of Mitral Incompetence Secondary to Ruptured Chordae Tendineae

Twenty-two patients with ruptured chordae tendineae are presented. Etiology was rheumatic heart disease in seven patients, bacterial endocarditis in four patients, both rheumatic heart disease and endocarditis in two patients, trauma in one patient, and aortic regurgitation in one patient. Exact cause of rupture was unknown in seven patients. Plastic repair of the leaflet and/or posteromedial annuloplasty was done in all the patients. In two patients the annuloplasty broke down soon after the operation and necessitated valve replacement. There was one hospital death. One patient died two years after operation probably because of cerebral embolism; a large thrombus was found in the left atrium at autopsy. All survivors have been followed for 7 months to 8 years and, except for two, are either working full-time or leading an active life.In ruptured chordae early and five-year results after repair of the leaflet and/or posteromedial annuloplasty are very good irrespective of the left atrial enlargement and “V” wave size. Results were better in the rheumatic group than in the nonrheumatic group. In our opinion this method of treatment is superior to prosthetic valve replacement for this condition, except if the annulus is thin and attenuated.

Platelet function during and after deep surface hypothermia.

Platelet function was studied during and after deep surface hypothermia in the canine model. In vivo determinations were made for platelet count, simultaneous [14C]serotonin and 51Cr-platelet survival, bleeding time, and aggregation in vitro. Transient platelet sequestration (cold-induced thrombocytopenia) was produced during deep hypothermia. Platelets, previously sequestered by hypothermia and subsequently mobilized, were shown to have a normal life span and function as measured by the bleeding time at 35°C rewarming. A transient impairment of in vitro platelet aggregation was observed during the first 212 hr after rewarming, but had recovered by 24 hr postrewarming. The constant ratio of [14C]serotonin:51Cr indicated no evidence of platelet dense body degranulation. Prolonged bleeding time at 20°C cooling could be largely explained by the transient thrombocytopenia, although platelet dysfunction also appeared to be associated.

Echocardiographic recognition of left ventricular aneurysm

Abstract An unusual, abnormal echocardiographic signal was detected during echocardiographic examination of the posterior left ventricular wall in a patient found to have a posterior left ventricular aneurysm, originating below the mitral annulus on the posterior lateral left ventricular wall. This finding supports the theory that the left ventricular wall is the origin of these posterior wall echoes and suggests that local areas of myocardial dysfunction may be detected by pulsed, reflected ultrasound.

Circulatory Dynamics during Surface-Induced Hypothermia under Halothane-Ether Azeotrope Anesthesia

Circulatory dynamics during surface- induced deep hypothermia using the halothane-diethyl ether azeotrope in 100% oxygen (O2) without circulatory arrest and 95% O2 and 5% carbon dioxide (CO2) with and without 60 minutes of arrest were evaluated in 15 adult mongrel dogs. Mean arterial pressure was lower in animals given 5% CO2 than in animals given 100% O2 during cooling. Cardiac output in the 5% CO2 groups increased until 30 degrees C cooling and then gradually decreased to 29% of control at 20 degrees C. Cardiac output in the 100% O2 group progressively decreased to 16% of control at 20 degrees C cooling and was 51 to 77% of the output in the 5% CO2 animals at comparable temperatures throughout the hypothermia procedure. The differences in cardiac output were attributed primarily to changes in stroke volume since heart rates were not significantly different. These changes were probably secondary to differences in systemic vascular resistance, which had increased sixfold in the animals given 100% O2 and had only doubled in the 5% CO2 groups at 20 degrees C during cooling. Hemodynamic variables in animals given 5% CO2 did not reveal significant differences in arrested versus nonarrested animals during early rewarming. However, with further warming, cardiac output, stroke volume, left ventricular stroke work, and mean pulmonary arterial and pulmonary artery wedge pressures were lower, and systemic and pulmonary vascular resistances were higher in the arrest group. We conclude that the improved results with halothane-diethyl ether azeotrope in 95% O2 and 5% CO2 during surface hypothermia are due to a greater cardiac output and reduced peripheral vascular resistance.

Improved Anesthesia for Deep Surface-Induced Hypothermia: The Halothane-Diethyl Ether Azeotrope

The halothane-diethyl ether azeotrope was evaluated in dogs as the anesthetic agent for deep surface hypothermia with total circulatory arrest for open-heart operation. All 10 animals given azeotrope in 100% oxygen (O2) experienced atrial arrhythmias during cooling, and 1 had ventricular fibrillation prior to the completion of cooling at 18 degrees to 20 degrees C. After only 30 minutes arrest, 8 of the 10 dogs had postoperative motor disturbances. Administering the azeotrope in 95% O2 and 5% carbon dioxide (CO2) yielded markedly improved results characterized by a rapid, smooth cooling course, easy resuscitation following circulatory arrest, and rapid rewarming, and 3 out of 10 dogs experienced mild motor disturbance after 60 minutes of circulatory arrest. This method, when compared with our standard method of ether in 100% O2, resulted in reduced blood lactates and a striking improvement in clinical status on the first postoperative morning. In limited clinical trials, infants undergoing repair of congenital cardiac defects have done well and responded as expected based on the laboratory experience. Since the results with the azeotrope in 95% O2 and 5% CO2 were at least as good as, and in several instances better than, those with the standard method employing either, the nonexplosive characteristic of the azeotrope warrants continued evaluation of this agent.