Natural history of congenital arteriovenous fistula.

There is no more difficult lesion to manage than congenital arteriovenous fistula. The advanced lesions are extremely vascular and unless they lend themselves to total excision, prompt recurrence is the rule. For the same reason, embolization is not successful and as the major feeding vessels are occluded, access to the tumor becomes more and more limited. In order to obliterate the tumor, it must be destroyed at the microvascular level. So far, only ethanol has proved effective in this regard, and this agent must be used conservatively to avoid excessive destruction of normal tissue and systemic damage.

Matas Lecture. Heparin--controversies and misconceptions.

The previous dogmas regarding heparin therapy are currently being challenged. It is apparent that the experimental work on which guidelines for heparin therapy are based do not necessarily have any relevance clinically. Once clotting has been initiated, there are multiple factors that result in a relative refractory response to heparin anticoagulation. In addition, it is now apparent that heparin's effect cannot be accurately monitored with current tests of anticoagulation. Most importantly, the risk of bleeding does not correlate with heparin levels but with clinical risk factors and to the presence or absence of functioning platelets. For this reason, sufficient heparin should be given initially to ensure that clotting is under control. If this is not done, all of the risk of heparin anticoagulation is assumed with none of the benefit. Life-threatening clotting conditions require high doses of heparin, equivalent to those required for cardiopulmonary bypass. Even though there is no good laboratory test available to ascertain the adequacy of anticoagulation, assessment of the clinical response is sufficient. When heparin levels are adequate, clinical improvement is evident as manifest by decreased pain and improvement in well-being, cardiac function, and/or collateral flow.

Low-dose heparin thromboembolism prophylaxis.

OBJECTIVE: To determine a rational approach to heparin dosing for thromboembolism prophylaxis. DESIGN: Literature review. RESULTS: Three commonly used heparin dosing regimens were identified: (1) standard low-dose heparin (5000 U administered subcutaneously 2-3 times per day); (2) adjusted-dose heparin (adequate to elevate the activated partial thromboplastin time to 5 seconds above the upper limit of normal); and (3) low-molecular-weight heparin (30 mg subcutaneously twice daily without monitoring). CONCLUSIONS: Adjusted-dose heparin thromboembolism prophylaxis is both the safest and most reliable method currently available.

Ligation and extraanatomic arterial reconstruction for the treatment of aneurysms of the abdominal aorta.

PURPOSE: Since Blaisdell et al. first described axillobifemoral bypass and aortic exclusion to treat patients at high risk with abdominal aortic aneurysms in 1965, this approach has been controversial. To help define the appropriate application of this procedure, the recent experience of the authors was reviewed. METHODS: Twenty-six patients underwent operation between March 1980 and August 1992. Mean age was 71 +/- 7 years. Average aneurysm diameter was 7.0 +/- 1.5 cm. Sixty-nine percent of the aneurysms were symptomatic; 21% were suprarenal. All patients had serious comorbid factors. All underwent axillobifemoral bypass with iliac artery ligation; the infrarenal aorta was also ligated in 62%. RESULTS: There were two postoperative deaths (7.7%). One- and two-year survival rates were 59% and 38%, respectively. Three patients died of aneurysm rupture (11.5%); the aorta had not been ligated in two of these patients. The remaining late deaths were due to comorbid conditions. Extraanatomic bypass grafts thrombosed in five patients; no limbs were lost. CONCLUSIONS: Axillobifemoral bypass without aortic ligation does not effectively reduce the risk of aneurysm rupture. However, axillobifemoral bypass with aortic ligation is an acceptable treatment for patients with severe medical problems and symptomatic, anatomically complicated, or large abdominal aortic aneurysms. Because the risk of aneurysm rupture is not completely eliminated, this procedure should be reserved for patients with high-risk aneurysms who would not tolerate direct aortic replacement.

Development of the city-county (public) hospital.

Prior to 1966, the United States had a two-tiered system of health care. Those patients who could afford the cost of medical care were treated by private physicians in their offices and in private hospitals. For patients who could not afford care, ie, the indigent and retirees over 65 years of age who developed catastrophic illnesses, the city and county (public) hospitals provided the only health care available. All counties assumed responsibility for their indigent patients, and all but the smallest counties had their local hospital. In the larger cities, these hospitals developed teaching programs and affiliations with medical schools that provided a volunteer teaching faculty (Table) (John G. Raffensperger, unpublished data, 1991; John E. Salvaggio, unpublished data, 1989). The smaller county hospitals relied on a few full-time generalists, but primarily they depended on volunteer physicians from the community to provide patient care.

Innovative treatment of deep venous disease.

The Council on Scientific Affairs of the California Medical Association presents the following inventory of items of progress in general surgery. Each item, in the judgement of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome, and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, researchers, and scholars to stay abreast of these items of progress in general surgery that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another. The items of progress listed below were selected by the Advisory Panel to the Section on General Surgery of the California Medical Association, and the summaries were prepared under its direction.

Visceral injuries.

Abdominal visceral injuries are encountered by every surgeon who deals with trauma. It is simple and useful to divide abdominal visceral injuries into those caused by penetrating mechanisms of injury and those due to blunt mechanisms. Determination of the need for operative intervention is generally easier after penetrating trauma. Gunshot wounds to the abdomen should be explored, as should stab wounds to the anterior abdomen that penetrate the fascia. A midline incision is the standard approach to abdominal visceral injuries because of its ease and versatility. Abdominal exploration should be consistent and systemic so as not to miss significant injuries. Hollow viscus injury is most common after penetrating injury, while blunt injury most often results in injury to solid viscera. Diagnostic and operative aspects of the treatment of specific visceral injuries are reviewed.

Neurologic consequences of cerebrovascular injury.

Because of ongoing controversy, the issue of vascular repair or ligation for patients with cerebrovascular injuries and preoperative central neurologic deficits is frequently debated. A total of 133 patients with penetrating cerebrovascular injuries were analyzed. The frequency of preoperative neurologic deficit was 20% (27 patients). The common carotid and internal carotid arteries were the most frequently injured structures, with a 29% and 15% incidence of preoperative neurologic deficits, respectively. The results of carotid repair in all patients whose preoperative deficit was limited to weakness or paralysis were favorable (seven patients normal or improved, two patients unchanged). The results of repair in patients whose preoperative deficit was characterized by obtundation were variable (four patients improved, four patients worsened or died). The results of carotid ligation were also variable (one improved, one unchanged, three worsened or died). Limited numbers of patients with preoperative neurologic deficits and the retrospective nature of this review prohibit definite conclusions. Therefore a multicenter, prospective, randomized trial of ligation or vascular repair for comatose patients with cerebrovascular injuries is proposed.

Multiple vessel injury to branches of the aortic arch: case report.

A case of multiple injuries to the branches of the aortic arch following blunt trauma is reported. Prompt diagnosis and early operation resulted in a favorable outcome.

Blunt intestinal injury. Keys to diagnosis and management.

Fifty-six patients with blunt intestinal injury seen during 39 months were reviewed for keys to diagnosis and treatment. Motor vehicle accidents were involved in 80% of the cases and seat/lap belts were in use 69% of the time. Blunt intestinal injury was the only abdominal injury in 70% of the cases. There were 42 perforations and 20 devascularizations; multiple injuries were common (27%). Abdominal tenderness was present on admission in 43 of 44 patients in whom a reliable examination was possible. Peritoneal lavage was positive in 13 (93%) of 14 patients. Computed tomography was falsely negative in three of four instances in which it was used. Perforations were most common in the upper and lower ends of the small bowel and in the sigmoid colon; devascularizations were most common in the distal ileum and sigmoid colon. Resection/anastomosis was performed in 38% of small-bowel perforations and in all small-bowel devascularizations. Resection/diversion was required in most colonic perforations (five of six patients) and devascularizations (four of six patients). There were five deaths (9%), none due to intestinal injury. There were seven complications related to intestinal injury. Diagnostic delay occurred in two patients; both had resultant morbidity. Blunt intestinal injury is associated with physical findings in conscious patients. Peritoneal lavage should be used when tenderness cannot be evaluated. Timely operative intervention minimizes morbidity and hospital stay.

Acquired and congenital clotting syndromes.

Although Virchow postulated 100 years ago that hypercoagulability states exist, it has only been in recent years that methods of documenting hypercoagulability have been developed. These clotting tendencies can be acquired or congenital. The common causes of acquired clotting tendencies include conditions which result in tissue and cellular damage, shock, transfusion reactions, and tissue necrosis. Certain drugs and drug reactions, and certain disease states which include blood dyscrasias and cancer are also associated with clotting problems. In certain diseases such as homocystinuria, hyperlipidemia, and lupus erythematosus, abnormal clotting tendencies may also develop. Important advances in the recognition of hypercoagulability have come with the documentation that congenital clotting abnormalities exist. Moreover, these abnormalities are proving to be more common than are congenital bleeding syndromes. Patients who appear to have spontaneous clotting manifestations and are under 40 years of age should be screened for one of these abnormalities. These congenital clotting tendencies can be classified as defects in thrombosis inhibitors, dysfibrinogenemias, or defects in fibrinolysis. The first thrombotic inhibitor defect recognized was antithrombin III deficiency which was reported in 1965. Subsequently, Protein C, Protein S, and Heparin cofactor II deficiencies have been recognized as contributing to thrombotic tendencies. Dysfibrinogenemias are relatively rare and most are associated with bleeding problems; however, 11% of the abnormal fibrinogens are associated with a clotting tendency. The reason appears to be that these fibrins are resistant to fibrinolysis. The most common defects which are associated with thrombotic tendencies appear, at the present time, to be due to defects in fibrinolysis. These include hypoplasminogenemia, decreases in plasminogen activator, increases in plasminogen activator inhibitor, and Factor XII deficiency.

Evaluation of an intraosseous infusion device for the resuscitation of hypovolemic shock.

An intraosseous infusion device designed for the prehospital administration of hypertonic saline-dextran solutions was evaluated by resuscitating hemorrhaged conscious sheep. Eight animals underwent 2 hours of hemorrhagic hypotension (50 mm Hg, bled volume = 43 +/- 7 ml/kg). This was followed by the intraosseous infusion of 200 ml (4-5 ml/kg) of 7.5% NaCl-6% dextran 70 into the bone marrow of the sternum. Results were compared to seven control animals (bled volume = 31 +/- 6 ml/kg) resuscitated through a central venous catheter. Despite the small volumes infused, mean arterial blood pressure and cardiac output were rapidly normalized in both groups by 10 minutes post resuscitation (p less than 0.01). Plasma sodium concentration increased an average of 12 mEq/L and plasma volume was rapidly expanded regardless of route. The metabolic acidosis of hemorrhagic shock was rapidly corrected, pulmonary pressures remained normal, and hypoxemia did not occur after intraosseous resuscitation. The device provided safe and rapid vascular access via the sternal bone marrow space. The use of intraosseous infusion of hypertonic saline dextran solutions via the sternal bone marrow may allow prehospital rescuers to consistently incorporate fluid replacement therapy into 'scoop and run' policies by avoiding the time delays associated with failures in IV access.

Traumatic hemipelvectomy: a catastrophic injury.

Traumatic hemipelvectomy is a catastrophic injury resulting from violent blunt shearing forces which cause massive skin, bone, and soft-tissue destruction. The initial extent of the injury as well as the complexity of the consequent problems is staggering. As such it constitutes one of the major challenges seen by trauma surgeons. Patients surviving traumatic hemipelvectomy are rare. We found a total of 36 cases reported in this century. The University of California at Davis General Surgery Trauma Service admitted 9,369 major trauma victims from June 1985 to May 1988. During this 3-year period eight patients sustained a traumatic hemipelvectomy, of whom three survived. Given the complexity, yet rarity, of this injury, a review of the world literature was undertaken to compile collective experiences to aid surgeons in the management of this injury.