Selective management of abdominal aortic aneurysms in a prospective measurement program.

PURPOSE: The purpose of this study was to clarify the treatment of patients with small abdominal aortic aneurysms (AAAs) less than 5 cm in diameter and those believed to be unfit for operation with AAAs 5 cm diameter or greater. METHODS: Four hundred ninety two patients with AAAs less than 5 cm when first seen were entered in a prospective measurement program by ultrasonography or computed tomography scan (exclusively after 1998) every 6 months. A decision regarding operative fitness was made when the AAA was 5 cm. Patients then underwent operation if fit or continued follow-up if their AAA was larger than 5 cm but they were unfit. A further group of 91 patients with aneurysms 5 cm or greater when first seen but unfit for repair were entered in the prospective measurement program. RESULTS: In the group with AAAs less then 5 cm at entry, operation was performed in 201 patients as a result of increase in AAA size to 5 cm or greater (157), AAA expansion of more than 0.5 cm in 6 months (24), or for other reasons (20). Of those with AAAs smaller than 5 cm at entry, 291 have not undergone operation at a mean follow-up of 42 months. Expansion was significantly related to aneurysm size at entry and was highest in the 4.5 to 4.9 cm group at 0.7 cm/year. In the group of patients deemed unfit for operation with 5 cm AAAs [as a graduate of the less than 5 cm group at entry (85 patients) or first seen with AAA greater than 5 cm (91 patients)], 10 ruptures have occurred. Of these patients with ruptured AAAs, six had AAAs between 5.0 and 5.6 cm. CONCLUSIONS: Because of the risk of rupture demonstrated in our series in AAAs 5 cm or slightly greater and the progressive increase in expansion to a mean of 0.7 cm/year in those AAAs between 4.5 and 4.9 cm at entry, recommendation for elective operation in patients with AAAs between 4.5 and 4.9 cm at entry, recommendation for elective operation in patients with AAAs between 4.5 and 5.0 cm should be strongly considered in a fit patient.

Thoracoscopic transthoracic dorsal sympathectomy.

The authors report on the three patients who underwent thoracoscopic transthoracic dorsal sympathectomies by the techniques of minimal-access surgery learned from laparoscopic cholecystectomy. All three had histologic confirmation of removal of the sympathetic chain and have had an encouraging early postoperative result. The authors believe that thoracoscopic transthoracic dorsal sympathectomy can be accurately and safely performed and will become the method of choice for dorsal sympathectomy.

The selective management of small abdominal aortic aneurysms: the Kingston study.

The management of small abdominal aortic aneurysms less than 5.0 cm maximum diameter remains controversial particularly in patients who are medically fit. All patients referred with abdominal aortic aneurysms less than 5.0 cm maximum diameter were prospectively followed regardless of their fitness for operation. Two hundred sixty-eight patients had been entered into the study by December 31, 1988, and monitored until December 31, 1990, by at least two aneurysm sizings by ultrasonography, CT scanning, or both. The mean follow-up was 42 months. Operations were performed on 114 patients (if they were fit for operation) when the aneurysm reached 5.0 cm, expanded more than 0.5 cm in a 6-month period, or when the patient had significant occlusive disease requiring repair. In this group the mean annual increase in diameter was 0.9 cm. One hundred fifty-four patients were monitored without operation for a mean period of 42 months. One rupture occurred in this group. The average annual increase in diameter in the group not undergoing operation was 0.24 cm. This study supports a policy of observation for abdominal aortic aneurysms less than 5.0 cm in maximum diameter.

Body water distribution after operation.

The effect of a major surgical procedure on the distribution of body water was investigated in two groups of patients. The first group of four patients did not receive any salt during the first 24 hours following operation, while the second group of five patients received a moderate amount of isotoric saline solution during this period. For seven days prior to operation, the patients were maintained by bed rest and a daily intake of 100 milliequivalents of sodium and 100 milliequivalents of potassium. A multiple isotope dilution technique was used, before and after operation, to measure red cell mass, plasma volume, extracellular water, total body water and total exchangeable sodium. In addition, the aldosterone secretion rate was measured, both before and after operation, to assess the physiologic control of the extracellular water volume. In the patients who did not receive any salt, the mean extracellular water volume decreased following operation from 39.7 to 37.5 per cent of the total body water; a mean decrease of 0.9 liter while the aldosterone secretion rate increased significantly, p less than 0.02, by 101 per cent from 206 to 414 micrograms per day. In the second group of patients who received an average of 1.3 liters of isotonic saline solution during the first 24 postoperative hours, the extracellular water increased from 37.9 to 42.8 per cent of total body water; a mean increase of 1.1 liters p less than 0.02. The mean aldosterone secretion rate in this group of patients increased by only 13 per cent from 167 to 188 micrograms per day. The blood volume did not change in either group as a result of operation. These data support the hypothesis that, following operation, sequestration of extracellular water occurs within the injured tissues, necessitating the postoperative infusion of a moderate amount of a balanced salt solution.

Differential renal function studies in the diagnosis of renal hypertension.

Over a 10-year period, positive criteria of the Howard test and the Rapoport Index have shown consistently good correlation with sustained relief or marked improvement in hypertension, in patients with main renal artery lesions. Similar correlation was obtained with ischemic criteria from histopathologic studies.Differential function studies did not reveal positive ischemic criteria in any patient operated upon for unilateral parenchymal disease. Histopathologic criteria of ischemia were also infrequent in this group. Nevertheless, marked improvement or cure of hypertension occurred in 62% of the latter. No factor can be used to predict improvement in this type of renal hypertension. Differential renal function criteria may occasionally appear to indicate renal artery ischemia in the more normal kidney in patients with unilateral parenchymal renal disease; wrong interpretation is avoided by taking differential creatinine clearance into account. Until vasopressor substances can be easily measured and accurately interpreted, aortography is indicated in selected patients.