Mack C. Stirling

Descending necrotizing mediastinitis: Transcervical drainage is not enough

One of the most lethal forms of mediastinitis is descending necrotizing mediastinitis, in which infection arising from the oropharynx spreads to the mediastinum. Two recently treated patients are reported, and the English-language literature on this disease is reviewed from 1960 to the present. Despite the development of computed tomographic scanning to aid in the early diagnosis of mediastinitis, the mortality for descending necrotizing mediastinitis has not changed over the past 30 years, in large part because of continued dependence on transcervical mediastinal drainage. Although transcervical drainage is usually effective in the treatment of acute mediastinitis due to a cervical esophageal perforation, this approach in the patient with descending necrotizing mediastinitis fails to provide adequate drainage and predisposes to sepsis and a poor outcome. In addition to cervical drainage, aggressive, early mediastinal exploration--debridement and drainage through a subxiphoid incision or thoracotomy--is advocated to salvage the patient with descending necrotizing mediastinitis.

Direct measurement of inner and outer wall thickening dynamics with epicardial echocardiography.

Simple geometric models of the left ventricle and indirect experimental measurements suggest that the inner myocardial wall contributes the largest fraction to total wall thickening. We measured transmural differences in regional wall thickening directly, using an epicardial M mode echocardiographic transducer (6 mm diameter, 5 MHz) placed on the anterior free wall of the left ventricle. Wall thickness was partitioned into inner and outer regions by inserting a waxed, 3-0 suture at different depths within the wall. The suture was used as an intramural echo target that was imaged simultaneously with the endocardium to determine inner and outer fractional contribution to total wall thickness. Data were collected in open-chest dogs at rest, during inotropic stimulation with isoproterenol, and during right heart bypass, which was used to vary cardiac output and preload. Results obtained with this method demonstrated that systolic wall thickness was nonuniform at rest and during each intervention. The fractional contributions to total wall thickening of the inner, middle, and outer thirds of the myocardial wall were estimated from the data to be 58%, 25%, and 17%, respectively. The experimental findings corresponded closely to theoretical predictions, supporting the conclusion that a gradient of thickening exists across the myocardial wall, with the inner portion of the wall contributing the largest fraction to total systolic thickening.

Esophagectomy for esophageal disruption

When esophageal disruption occurs in the presence of preexisting esophageal disease or is associated with sepsis or fluid and electrolyte imbalance, aggressive and definitive therapy often provides the only chance for patient salvage. Twenty-four adults (average age, 59 years) with intrathoracic esophageal perforations underwent esophagectomy: 15, transhiatal esophagectomy without thoracotomy; and 9, transthoracic esophagectomy. Restoration of alimentary continuity with an immediate cervical esophagogastric anastomosis was carried out in 13 patients. Eleven underwent a cervical or anterior thoracic esophagostomy, and 10 of them had a subsequent colonic (7) or gastric (3) interposition from 4 to 32 weeks (average time, 8.6 weeks) later. The perforations were due to esophageal instrumentation (9 patients), acute caustic ingestion (2), emesis (2), intrathoracic esophagogastric anastomotic disruption (2), and other causes (9). Preexisting esophageal disease in 20 patients included chronic strictures (10 patients), reflux esophagitis (3), esophageal cancer (3), achalasia (2), diffuse spasm (2), and monilial esophagitis (1 patient). Ten patients were operated on within 12 hours after the injury; 3, within 12 to 24 hours; and 11, within three to 45 days (average interval, 6.6 days). There were three hospital deaths (13%). Nineteen of the 21 survivors were able to swallow comfortably until the time of death or latest follow-up. Aggressive diagnosis and aggressive treatment of life-threatening esophageal perforations are advocated. Conservative procedures (repair, diversion, or drainage) for a perforation with preexisting esophageal disease often inflict more morbidity than esophageal resection, which eliminates the perforation, the source of sepsis, and the underlying esophageal disease. The decision to restore alimentary continuity in a single stage must be individualized.

Esophageal resection for achalasia: Indications and results☆

Although esophagomyotomy is highly effective as the initial surgical treatment of most patients with achalasia, those with either recurrent symptoms after a previous esophagomyotomy or a megaesophagus do not respond as well to esophagomyotomy. Total thoracic esophagectomy was performed in 26 patients (average age, 49 years) with achalasia. Eighteen had a history of a previous esophagomyotomy, and 18 had a megaesophagus (esophageal diameter of 8 cm or larger). In 24 patients, a transhiatal esophagectomy without thoracotomy was the operative approach; 2 patients required a transthoracic esophagectomy because of intrathoracic adhesions from prior operations. The stomach was used as the esophageal substitute in all patients; it was positioned in the posterior mediastinum, and a cervical anastomosis was performed. Intraoperative blood loss averaged 765 mL. Major postoperative complications included mediastinal bleeding requiring thoracotomy (2), chylothorax (2), and anastomotic leak (1). There were no postoperative deaths. The average postoperative hospital stay was ten days. Follow-up is complete and ranges from 3 to 91 months (average duration, 30 months). All but 1 patient with severe psychiatric disease eat a regular, unrestricted diet without postprandial regurgitation. Early postoperative anastomotic dilation was required in 10 patients. Dumping syndrome has occurred in 5 patients. It is concluded that esophagectomy provides the most reliable treatment of esophageal obstruction, pulmonary complications, and potential late development of carcinoma in the patient with a megaesophagus of achalasia or a failed prior esophagomyotomy and that it is a far better option in these patients than esophagomyotomy, cardioplasty procedures, or limited esophageal resection.

The functional border zone in conscious dogs.

Studies focusing on the functional border zone have been performed largely with anesthetized, open-chest preparations. Therefore, we instrumented 14 dogs at sterile surgery with sonomicrometers arrayed to measure systolic wall thickening across the perfusion boundary produced by circumflex coronary occlusion. We fitted sigmoid curves to the data to model the distribution of wall thickening impairment as a function of distance from the perfusion boundary, which was delineated with myocardial blood flow (15 micron diameter microspheres) maps. Using this approach, we defined the functional border zone as the distance from the perfusion boundary to 97.5% of the sigmoid curves nonischemic asymptote. The lateral extent of the functional border zone, measured 10 min and 3 hr after occlusion, was 32 and 28 degrees of circumference, respectively. To evaluate the severity of nonischemic dysfunction, we measured average systolic wall thickening within the functional border zone. It was reduced from 3.69 +/- 1.10 (mean +/- SD) mm to 2.98 +/- 1.07 mm (p less than .01) and 2.74 +/- 1.12 mm (p less than .01) early and late after coronary occlusion. Thus, a narrow functional border zone was evident during circumflex coronary occlusion in conscious dogs. Its lateral extent was limited to approximately 30 degrees (similar to findings in open-chest, anesthetized dogs), severe dysfunction was restricted to the immediate vicinity of the perfusion boundary, and the average severity of nonischemic dysfunction within the functional border zone was mild.

The Combined Collis-Nissen Operation for Esophageal Reflux Strictures

This report evaluates the efficacy of the combined Collis-Nissen operation in achieving long-term reflux control in patients with reflux strictures. A Collis-Nissen procedure with dilation of a reflux stricture was performed in 64 adults. The strictures were mild (easily dilated) in 37, moderate (requiring some force to dilate) in 17, and severe (requiring very forceful dilation) in 10. Two strictures were perforated intraoperatively. There was 1 postoperative death, and 4 patients have been lost to follow-up. The remaining 59 patients have been followed from 2 to 120 months (average, 43 months) after operation. Subjectively, reflux is absent in 48 (81%), mild in 4 (7%), moderate in 5 (9%), and severe in 2 (3%). Objectively, intraesophageal pH studies show good or excellent reflux control in 94% at 1 year and 66% at 2 to 5 years. Dysphagia has been eliminated in 71%, is mild in 10%, moderate (requiring occasional dilation) in 12%, and severe (requiring regular dilations) in 7%. The combined Collis-Nissen operation provides good long-term reflux control and relief of dysphagia in most patients with reflux strictures. However, patients with reflux strictures after previous repairs are likely to have unsatisfactory results and may best be managed with resectional therapy. Resection may also ultimately prove to be a better option for patients with more severe strictures.

Cardiac pheochromocytoma involving the left main coronary artery presenting with exertional angina

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Effects of ischemia on epicardial segment shortening

To evaluate the effects of nontransmural ischemia on epicardial contractile function, we implanted sonomicrometers in 15 open-chest, anesthetized (halothane) dogs. One cylindrical crystal (radiating ultrasound 360 degrees) was used as a transmitter for three conventional flat plate crystals arrayed to measure epicardial segment shortening along three different axes that were deviated 0 degree (parallel), 45 degrees (oblique), and 90 degrees (perpendicular) from surface fiber orientation in the anteroapical or posterior-basal left ventricle. During baseline conditions, epicardial shortening was maximal parallel with fiber orientation. Shortening decreased in a non-linear manner as deviation from fiber orientation increased, but there were significant differences between the two left ventricular regions suggesting that more substantial lateral strain occurs in the anterior-apical than the posterior-basal area. During coronary inflow restriction, changes in epicardial segment shortening also varied greatly depending on location and alignment. At levels of wall thickening impairment associated with normal subepicardial perfusion, changes in epicardial function were restricted to the segments aligned perpendicular to fiber orientation whereas the parallel and oblique segments displayed moderate dysfunction or none at all. Thus, transmural tethering modifies epicardial segmental motion during coronary inflow restriction, but the severity of the influence depends on the alignment and location of the epicardial measurements.

Comparison of Polyclonal Antibody Sera for Early Prophylaxis following Cardiac Transplantation

In order to test different polyclonal antibody regimes as early prophylaxis against cardiac rejection, 42 patients (ages 30 to 60 years) transplanted at the University of Michigan from December 1986 to August 1988 were randomized to receive antithymocyte globulin (ATGAM, Upjohn, n = 19) or antilymphoblast globulin (MALG, University of Minnesota, n = 23). Cyclosporine (CYA), steroids, and azathioprine (AZA) administration was similar in all randomized patients during early prophylaxis. CYA was begun preoperatively and maintained at a serum level of 250-300 ng/ml. After an initial steroid taper, patients were maintained on 0.3 mg/kg/day. AZA was begun after polyclonal prophylaxis at 1-2 mg/kg. All patients received either ATGAM or MALG for 7 days or until the serum CYA reached 250 ng/ml. Although sex, pretransplant hemodynamics, follow-up length, total drug dose, mortality (one per group), postoperative white blood cell and lymphocyte counts did not differ between groups, MALG significantly delayed the first rejection episode as compared to ATGAM (35 +/- 4 vs 22 +/- 3 days, P less than 0.05). Additionally, there was decreased rejection during follow-up for the MALG group with 1.5 +/- 0.2 rejections per patient as compared to 2.3 +/- 0.3 with ATGAM. Furthermore, the significant infection rate with MALG was only half that of the ATGAM group (6/23 vs 11/19) (P less than 0.05). The beneficial effect of MALG may be due to immune-specific differences in its polyclonal spectrum.