Glenn E. Newman

Mechanisms of major biliary injury during laparoscopic cholecystectomy.

Laparoscopic cholecystectomy has become the procedure of choice for surgical removal of the gallbladder. The most significant complication of this new technique is injury to the bile duct. Twelve cases of bile duct injury during laparoscopic cholecystectomy were reviewed. Eight injuries were of a classic type: misidentification of the common duct for the cystic duct, resection of part of the common and hepatic ducts, and associated right hepatic arterial injury. Another injury was similar: clip ligation of the distal common duct with proximal ligation and division of the cystic duct, resulting in biliary obstruction and leakage. Three complications arose from excessive use of cautery or laser in the region of the common duct, resulting in biliary strictures. Evaluation of persistent diffuse abdominal pain led to the recognition of ductal injury in most patients. Ultimately, 10 patients required a Roux-en-Y hepaticojejunostomy to provide adequate biliary drainage. One patient had a successful direct common duct repair, and the remaining patient underwent endoscopic dilatation.

Cardiac Function at Rest and During Exercise in Normals and in Patients with Coronary Heart Disease: Evaluation by Radionuclide Angiocardiography

This study demonstrates that radionuclide angiocardiography provides a simple and noninvasive approach for evaluation of myocardial function. Previous work concerning myocardial performance has been generally conducted with the patient in the supine position. Radionuclide angiocardiograms were performed in the present study at rest and during exercise in 30 normal subjects and in 30 patients with ischemic coronary artery disease. There were 30 normal controls (Group I), ten with single coronary artery disease (Group II), and 20 patients with multiple vessel coronary disease (Group III). All subjects were studied in the erect posture on a bicycle ergometer. In the normal controls, the mean heart rate doubled and the cardiac output tripled during exercise. Intensive training can lead to extraordinary levels of cardiac performance as shown in a world-class athlete who during peak exercise attained a heart rate of 210, an ejection fraction of 97%, and a cardiac output of 56 liters per minute. In the patients with coronary artery disease, both groups were able to increase cardiac output to approximately twice the resting value. The magnitude of increase in blood pressure during exercise was not significantly different in the three groups. However, definite changes were present in the end-diastolic volume at rest compared with exercise. The mean end-diastolic volume at rest was 116 and rose to 128 ml in Group I, 93 rising to 132 ml in Group II, and 138 increasing to 216 ml in Group III. The stroke volume increased comparably in all three groups, but the ejection fraction from rest to exercise showed a marked contrast in the controls compared to those with multivessel coronary disease. The ejection fraction rose in Group I from 66 to 80% during exercise, while in Group II it fell from 69 to 67%, and in Group III from 60 to 46%. These findings indicate that patients with ischemic myocardial disease respond to the stress of exercise by cardiac dilatation to maintain or increase stroke volume at increased heart rates. Moreover, the magnitude of this response appears to be greatest in patients with left main coronary artery stenosis. This approach for evaluating myocardial function during exercise provides useful data of importance in selecting medical versus surgical management of patients with ischemic coronary artery disease.

Accuracy of diagnosis of coronary artery disease by radionuclide management of left ventricular function during rest and exercise.

Rest and exercise radionuclide angiocardiographic measurements of left ventricular function were obtained in 496 patients who underwent cardiac catheterization for chest pain. Two hundred forty-eight of these patients also had an exercise treadmill test. An ejection fraction less than 50% was the abnormality of resting left ventricular function that provided the greatest diagnostic information. In patients with normal resting left ventricular function, exercise abnormalities that were optimal for diagnosis of coronary artery disease were an ejection fraction at least 6% less than predicted, an increase of greater than 20 ml in end-systolic volume and the appearance of an exercise-induced wall motion abnormality. The sensitivity and specificity of the test were lower in patients who were taking propranolol at the time of study and in patients who failed to achieve an adequate exercise end point. In the 387 patients with an optimal study, the test had a sensitivity of 90% and a specificity of 58%. Radionuclide angiocardiography was more sensitive and less specific than the exercise treadmill test. The high degree of sensitivity of the radionuclide test suggests that it is most appropriately applied to patient groups with a high prevalence of disease, including those considered for cardiac catheterization.

CRITICAL ANALYSIS OF SUPRACOSTAL ACCESS FOR PERCUTANEOUS RENAL SURGERY

PURPOSE Percutaneous renal surgery is currently performed for complex renal calculi as well as for various other endourological indications. In many patients an upper pole nephrostomy tract allows direct access to most of the intrarenal collecting system. Upper pole percutaneous access may be obtained via the supracostal or subcostal approach. The preferred route depends on the location and size of the specific stone or lesion. Previously others have cautioned against the supracostal approach above the 12th rib and many have discouraged an approach above the 11th rib due to concern about the increased risk of intrathoracic complications. We retrospectively assessed the morbidity associated with supracostal percutaneous renal surgery and compared and analyzed the morbidity of the supracostal and subcostal approaches. MATERIALS AND METHODS The records of all patients who underwent upper pole percutaneous renal surgery between November 1993 and July 1999 were retrospectively reviewed. A total of 240 patients underwent percutaneous renal procedures, including 225 for managing symptomatic renal or ureteral stones, that is nonstaghorn calculi in 157, staghorn calculi in 41, proximal ureteral calculi in 12, calculi within a caliceal diverticulum in 6, calculi associated with primary ureteropelvic junction obstruction in 5 and calculi associated with a retained ureteral stent in 4. An additional 15 procedures were done for ureteropelvic junction obstruction (7), intrarenal collecting system tumors (5), a caliceal diverticulum without stones (1), a retained ureteral stent (1) and a ureteral stricture (1). RESULTS A total of 300 nephrostomy tracts were placed to obtain access to the intrarenal collecting system via the supracostal approach in 98 (32.7%) cases and the subcostal approach in 202 (67.3%). Of the supracostal approaches 72 (73.5%) tracts were above the 12th and 26 (26.5%) were above the 11th rib. The overall complication rate irrespective of percutaneous approach was 8.3% (16.3% for supracostal and 4.5% for subcostal access). Complications included blood transfusion in 7 patients, intraoperative hemothorax/hydrothorax in 5, sepsis/bacteremia in 3, atrial fibrillation in 2, delayed nephropleural fistula in 2, renal artery pseudoaneurysm in 2, deep venous thrombosis/pulmonary embolus in 2, pneumothorax in 1 and subcapsular hematoma in 1. Seven of 8 intrathoracic complications (87.5%) developed in supracostal cases. CONCLUSIONS Percutaneous renal surgery remains an important option for managing complex renal calculi and other upper urinary tract lesions. In our experience it is generally associated with low morbidity. The supracostal approach is often preferred for obtaining intrarenal access to complex renal and proximal ureteral pathology. Because supracostal access tracts are associated with significantly higher intrathoracic and overall complication rates compared to subcostal access tracts, this approach must be used with caution when no other alternatives are available.

Significance of subendocardial S-T segment elevation caused by coronary stenosis in the dog

A model of partial thickness ischemia has been developed using subendocardial S-T elevation without epicardial S-T elevation to detect partial thickness ischemia which is sufficient to cause subsequent necrosis. Subendocardial blood flow in this model (measured with radioactive microsphere techniques) may be reduced to 25 percent of normal (P less than 0.001) by coronary stenosis and tachycardia while subepicardial flow remains normal. Epicardial S-T depression seems to indicate reciprocally subendocardial S-T elevation as long as a layer of nonischemic epicardial muscle is present, but when ischemia becomes transmural, epicardial S-T elevation occurs. Regional pressure-flow relations were determined as distal coronary pressure was reduced at a constant aortic pressure, heart rate and cardiac output. These relations revealed remarkably effective autoregulation of epicardial blood flow concomitant with progressive subendocardial ischemia.

Detecting abnormalities in left ventricular function during exercise before angina and ST-segment depression.

To determine if abnormalities in left ventricular function precede angina pectoris and electrocardiographic evidence of myocardial ischemia, we used radionuclide angiocardiography to measure left ventricularejection fraction, volumes, cardiac output and wall motion in 10 normal subjects and 25 patients with coronary artery disease at rest and during two levels of upright bicycle exercise. In the patients with coronary artery disease, the first radionuclide study during exercise was performed before and the second after the onsetof ST-segment depression. In all normal subjects, the ejection fraction increased more than 5%, the end-diastolic volume increased less than 25% and the end-systolic volume decreased from rest to both levels of exercise. Wall motion was normal at rest and increased with exercise. No patient with coronary artery disease had chest pain or ST-segment depression during the first level of exercise. The ejection fraction either decreased or increased less than 5% in 18 patients, the end-diastolic volume increased more than 25% in nine, the end-systolic volume increased in 19 and a segmental contraction abnormality developed in 14. Hemodynamic and wall motion abnormalities occurred in all patients during the second level of exercise when ST-segment depression was present. During exercise in patients with coronary artery disease, abnormalities in left ventricular function frequently develop before angina pectoris and electrocardiographic evidence of myocardial ischemia.

The reproducibility of radionuclide angiographic measurements of left ventricular function in normal subjects at rest and during exercise.

SUMMARYIn this investigation we determined the reproducibility of radionuclide measurements of left ventricular ejection fraction, end-diastolic volume, end-systolic volume, stroke volume, pulmonary transit time, pulmonary blood volume and cardiac output in 10 normal subjects. First-pass radionuclide angiocardiograms were performed at rest and during upright, submaximal bicycle exercise on day 1 and day 3. The resting heart rate for the group decreased from 79 ± 17 beats/min on day 1 to 71 ± 14 beats/min on day 3 (p < 0.01). This biologic variation probably contributed to the small but significant decreases in ejection fraction (62 ± 7 to 59 ± 7%, p < 0.05) and cardiac output (7.7 ± 1.9 to 6.6 ± 1.5 l/min, p < 0.02), and the increase in pulmonary transit time (5.8 1.6 to 6.2 ± 1.3 seconds, p < 0.05) between day 1 and day 3. The mean variabilities in ejection fraction, cardiac output and pulmonary transit time were 4.0 ± 3.8%, 1.24 ± 1.23 1/min and 0.65 ± 0.64 second, respectively. No significant differences between studies were observed in resting end-diastolic volume, end-systolic volume and stroke volume. The mean variability in enddiastolic volume was 9.9 ± 5.1 ml. Heart rate varied less during exercise to the same work load, and only pulmonary transit time and blood volume differed significantly between studies. During exercise the mean variabilities in ejection fraction, enddiastolic volume, cardiac output and pulmonary transit time were 3.2 ± 2.5%, 9.8 ± 6.2 ml, 1.59 ± 0.67 1/min and 0.25 ± 0.25 second, respectively. Radionuclide measurements of left ventricular function are highly reproducible if obtained under comparable hemodynamic conditions.

Pain after Percutaneous Nephrolithotomy: Impact of Nephrostomy Tube Size

BACKGROUND AND PURPOSE Percutaneous nephrolithotomy (PCNL) is the procedure of choice for managing large renal calculi. Investigations have recently focused on reducing the morbidity of the procedure and improving postoperative patient comfort by using smaller endoscopic instruments. We sought to evaluate the effect of a smaller percutaneous drainage catheter on postoperative pain. PATIENTS AND METHODS Thirty consecutive patients were randomized to receive either a 10F pigtail catheter or a 22F Councill-tip catheter for their percutaneous drainage after PCNL. The demographics were similar in the two groups, as was the rate of supracostal access (47% v 43%, respectively). Self-assessed analog pain scores were collected at 6 hours postoperatively as well as on the morning of the first and second postoperative days (POD). Total narcotic usage was tabulated using morphine equivalents. Complications, including the change from baseline hematocrit, were reviewed. RESULTS There was no significant difference in the change in hematocrit (6.8 v 6.2 percentage points, respectively). Those patients with the smaller nephrostomy tube noted significantly lower pain scores at 6 hours (3.75 v 5.3; P=0.03). Although the pain scores were lower on POD 1 and 2 for the 10F catheter group, the difference was not statistically different (1.9 v 2.9 and 1.25 v 1.9, respectively; both P>0.05). The patients having the 10F catheter required fewer narcotics: 78 mg v 91 mg, although the difference was not statistically significant. CONCLUSION The use of a small drainage catheter after PCNL is associated with lower pain scores in the immediate postoperative period, yet no statistically significant benefit to the patient with regard to comfort is demonstrated beyond 6 hours. In addition, there is a trend toward reduced narcotic requirements. Finally, there is no apparent increase in patient morbidity from the use of the smaller nephrostomy tubes.

Augmentation and Redistribution of Myocardial Blood Flow During Acute Ischemia by Intraaortic Balloon Pumping

Abstract Regional coronary blood flow (CBF) in the acutely ischemic, normotensive ventricle was evaluated using radionuclide-labeled microspheres. Intraaortic balloon pumping (IABP) significantly increased CBF to myocardium made ischemic by either total or partial coronary artery occlusion. Both subendocardial and myocardial CBF in the ischemic area were increased by IABP, associated with a slight but not significant decrease in CBF to normally perfused areas of myocardium. The heart in this setting appears to autoregulate local CBF in response to IABP.

Malpositioned Peritoneal Dialysis Catheters: A Critical Reappraisal of Correction by Stiff-Wire Manipulation

Tenckhoff peritoneal dialysis (PD) catheter malposition is one of the leading causes of catheter malfunction. Fluoroscopically directed stiff-wire manipulation of malpositioned PD catheters has been advocated as a method of catheter salvage. Two hundred eighty-nine single-cuff PD catheters were placed surgically into 203 patients during this 4-year study. Thirty-three patients developed catheter malfunction attributed to malposition. Forty-eight stiff-wire manipulations were performed on these patients. Thirty-eight (78%) of the manipulations were described as successful at the time of transfer from radiology. However, only 25 (51%) and 12 (25%) resulted in functioning catheters at 1 week and 1 month, respectively. Only 11 of 33 patients who underwent manipulation had functional prolongation of catheter life beyond 1 month. The PD catheter was replaced by a column-disk PD catheter without additional catheter dysfunction in six patients. A second single-cuff Tenckhoff PD catheter was inserted in another six patients. Three of these six catheters again malpositioned. We conclude that stiff-wire manipulation is a useful and safe technique worth using on a limited basis for the initial episode of catheter malposition. Catheters that repetitively malposition should be replaced with a catheter that is resistant to malpositioning.