A prospective study of the incidence of deep venous thrombosis in hospitalized children.

PURPOSE: It is commonly believed that the incidence of deep venous thrombosis (DVT) in hospitalized children is less than in adults. However, it is possible that the disease is significantly underdiagnosed in children because the index of suspicion of pediatric practitioners is low, a substantial number of patients may have no symptoms, and DVT screening is not routinely performed. We therefore undertook a prospective study to define the incidence of DVT in hospitalized children with no symptoms. METHODS: Patients included in the study were those younger than 18 years of age who were hospitalized for more than 72 hours and were identified to have two or more risk factors for the development of DVT and had at least one screening duplex scan. Risk factors for the development of DVT considered were a history of DVT or pulmonary embolism, recent operation, immobilization, trauma, stroke or acute neurologic deficit, the presence of cancer, sepsis, greater than 150% ideal body weight, a hypercoagulable state, and the presence of a femoral venous catheter. RESULTS: Over the 9-month period ending December 1994, 1997 patients 17 years of age and younger were admitted to the hospital, and 59 patients including 19 girls and 40 boys were enrolled in the study. The one patient with DVT was a 17-year-old boy hospitalized after a motor vehicle accident with blunt head trauma and a neurologic deficit who underwent multiple orthopedic and neurosurgical procedures. CONCLUSIONS: The development of acute DVT in children is unusual. As a result, DVT prophylaxis and screening is unnecessary in young children with only two risk factors for the development of the disease. Young age appears to be an important protective risk factor for the prevention of DVT.

Acute peritoneal dialysis following ruptured abdominal aortic aneurysms.

BACKGROUND: Acute renal failure is common after repair of ruptured abdominal aortic aneurysm. Early dialysis has recently been advocated to reduce the mortality associated with multiorgan failure, but hemodialysis (HD) is not well-tolerated in critically ill patients because of hemodynamic instability and risk of bleeding from anticoagulation therapy. Peritoneal dialysis (PD) has the advantage in that it causes minimal cardiopulmonary instability and does not require anticoagulation. The presence of a freshly-closed abdominal wound and an aortic graft, however, have previously been considered to be contraindications to PD. METHODS: Peritoneal dialysis catheters were placed in 69 of the 105 patients who underwent grafting for a ruptured abdominal aortic aneurysm between 1982 and 1993. Criteria for placement included shock, perioperative oliguria, and preoperative renal insufficiency. All charts were reviewed retrospectively to evaluate the safety and efficacy of placing PD catheters and initiating early dialysis in patients at risk for developing acute renal failure. RESULTS: Acute tubular necrosis developed in 31 patients, 19 of whom required dialysis. Peritoneal dialysis alone provided effective dialysis in 8 patients, and it was combined with hemofiltration and/or HD in 9 additional patients for an overall efficacy of 58%. The peritoneal catheter also facilitated the early diagnosis of peritonitis due to colon ischemia in 5 patients, and was helpful in diagnosing intra-abdominal hemorrhage in 4 others. Bacterial peritonitis occurred in 3 (17%) patients undergoing PD with no cause noted for the infection diagnosing other than use of the PD catheter. A single aortic graft infection was diagnosed 4.2 years postoperatively with an enteric organism in a patient with recurrent diverticulitis. Two patients with peritoneal catheters developed abdominal wound dehiscence, but neither had undergone PD (P > 0.2). In a multivariate analysis, placement of a PD catheter did not affect survival. CONCLUSIONS: Placement of a PD catheter at the time of resection of a ruptured abdominal aortic aneurysm in patients at risk for development of acute renal failure is without significant complications and can facilitate early and effective dialysis. The peritoneal dialysis catheter may also be useful in making an early diagnosis of intraperitoneal bleeding and infection.

Optimal grafting methods for the small abdominal aorta.

Aortobifemoral bypass procedures were performed on 42 patients with the hypoplastic aortoiliac syndrome over an eight year period. During the first five years, 22 patients had either a 13 X 6.5 mm or a 14 X 7 mm knitted Dacron graft and served as historic controls for a second group of 20 others who had 14 X 7 mm grafts of expanded polytetrafluoroethylene (PTFE), during the last three years of the study. Although the two groups were neither concurrent nor randomized, they were nonetheless well matched with regard to age, sex, risk factors, indications for operations, distribution and severity of distal occlusive disease, and type of distal anastomosis. There was only one early graft limb occlusion in the PTFE group after a median follow-up of 14 months, compared to nine occlusions and one amputation in the Dacron group after a median follow-up of 26.2 months. The cumulative patency of the PTFE grafts was 95% at four years compared to only 52% for Dacron (p = 0.11). If the single postoperative occlusion which occurred in each group is excluded, then the difference in patency rates bordered on statistical significance (p = 0.06). Inclusion of the profunda femoris orifice in the distal anastomosis was also found to be an important factor contributing to long-term patency which approached statistical significance (p = 0.075). The configuration of the proximal aortic anastomosis (end to end vs. end to side), or the concomitant use of lumbar sympathectomy or the postoperative infusion of Dextran did not have a statistically significant influence on patency.(ABSTRACT TRUNCATED AT 250 WORDS)

Prediction of the development of sigmoid ischemia on the day of aortic operations. Indirect measurements of intramural pH in the colon.

A deviation in an indirect measurement of intramural pH below the limits of normality (6.86) was used as a diagnostic test for sigmoid ischemia in 25 high-risk patients undergoing abdominal aortic operations. The clinical diagnosis of ischemic colitis was made by the attending physicians in only two of the 25, on the day after operation in one and three months after operation in another. In neither was the ischemic colitis considered to have been a causative factor in their subsequent deaths. In contrast, six patients developed pH evidence of ischemia on the day of operation. All six subsequently developed a transient episode of guaiac-positive diarrhea, four developed physical signs consistent with ischemic colitis, and four died. Of 19 who did not develop pH evidence of ischemia, none developed guaiac-positive diarrhea, none developed any signs of ischemic colitis, and none died. Stepwise logistic regression showed the duration of pH evidence of ischemia on the day of operation to be the best predictor for the symptoms and signs of ischemic colitis and for death after operation.

Free-floating iliofemoral thrombus. A risk of pulmonary embolism.

We retrospectively evaluated the risk of pulmonary embolism in hospitalized patients with venographically proved iliofemoral deep vein thrombosis (DVT). Venograms and clinical records of 78 patients with iliofemoral DVT were reviewed and the proximal intraluminal thrombus was characterized as free-floating (greater than 5-cm nonadherent segment) or occlusive (no free-floating elements). The incidence of pulmonary embolism confirmed by high-probability radioisotope ventilation-perfusion lung scanning within ten days following venography was 9% (7/78) and was associated with 60% (3/5) free-floating and 5.5% (4/73) occlusive phlebographic criteria (P less than .05). All patients who experienced pulmonary embolism were given therapeutic heparin treatment (partial thromboplastin time, more than twice the control value). The mean (+/- SD) time from the diagnosis of DVT to pulmonary embolism was 104 +/- 60 hours, and 120 +/- 71 hours for patients with free-floating and occlusive thrombi, respectively (P greater than .05). Patients with iliofemoral DVT that met free-floating criteria are at significant risk for pulmonary embolism, despite the administration of heparin.

Noninvasive detection of carotid stenosis following endarterectomy.

Noninvasive diagnostic studies (oculoplethysmography, pulsed Doppler arteriography, and phonoangiography) were used to follow the postoperative courses of 172 patients who had 199 carotid endarterectomies. There were 24 restenotic arteries in 21 patients who underwent 29 operations. Fifteen restenotic lesions in 14 patients were detected solely by noninvasive testing. These patients are being observed closely and remain asymptomatic. One has been operated on for progression of disease. Either transient or permanent neurologic deficits developed in nine as the initial indication of recurrent stenosis or occlusion; three of these subsequently have undergone reoperation. Patients with bilateral disease are at increased risk of restenosis. Routine testing of all patients undergoing carotid endarterectomy is recommended 1, 3, and 12 months postoperatively to detect and observe stenosis on both the side operated on and the contralateral side before clinical symptoms develop.

Limitations of noninvasive evaluation of carotid occlusive disease.

A series of 32 patients examined by two different noninvasive techniques in two different laboratories and by cerebral angiography were retrospectively studied. Significant differences in ophthalmic artery pressures as measured by oculopneumoplethysmography (OPPG), and significant delays in ocular pulse arrival time combined with characteristic recorded bruits as determined by oculoplethysmography/carotid phonoangiography (OPG/CPA) were considered as an index of carotid stenosis. Cerebral angiography was performed on all 32 patients to confirm or refute the diagnosis suggested by noninvasive testing. In this selected group of patients with difficult diagnostic problems, only 67% of significant (greater than 50% diameter) stenoses were detected by OPPG, and only 58% by OPG/CPA. Combining OPPG and OPG/CPA increased the probability of detecting a greater than 50% diameter stenosis to 92%.

A simplified method for evaluating peripheral arterial occlusive disease in a clinical vascular laboratory.

A relatively simple, inexpensive, and accurate procedure for the vascular laboratory evaluation of patients with suspected peripheral arterial occlusive disease is described. This method was evaluated in a series of 110 limbs in 58 patients seen in the Vascular Laboratory at the Worcester City Hospital. All patients were evaluated clinically and angiographically as well, to provide additional standards for evaluation. The method described was 100% accurate in predicting the presence or absence of significant occlusive disease, and over 90% accurate in defining the location of the major occlusive process. The method utilizes a combination of two well-established measurements--ankle systolic pressure and ankle pulse wave amplitude--as a screening method for determining the presence or absence of significant occlusive disease. Only patients with abnormal findings are tested further, resulting in a considerable savings in time and expense in the clinical vascular laboratory. The method may also prove valuable for following patients with known vascular disease for evidence of progression and for evaluating the effectiveness of various reconstructive procedures. Other methods and instruments may be adapted utilizing the same general principles.