Giacomo A. DeLaria

Effects of epidural anesthesia and analgesia on coagulation and outcome after major vascular surgery.

To examine the interaction of epidural anesthesia, coagulation status, and outcome after lower extremity revascularization, 80 patients with atherosclerotic vascular disease were prospectively randomized to receive general anesthesia combined with postoperative epidural analgesia (GEN-EPI) or general anesthesia with on-demand narcotic analgesia (GEN). Demographics did not differ between groups except that the GEN-EPI group had a higher incidence of diabetes mellitus and of previous myocardial infarction. Coagulation status was monitored using thromboelastography. An additional 40 randomly selected patients without atherosclerotic vascular disease undergoing noncardiovascular procedures served as controls for coagulation status. Vascular surgical patients were hypercoagulable compared with control patients before operation and on the first postoperative day. Postoperatively, this hypercoagulability was attenuated in the GEN-EPI group and was associated with a lower incidence of thrombotic events (peripheral arterial graft coronary artery or deep vein thromboses). The rates of cardiovascular, infectious, and overall postoperative complications, as well as duration of intensive care unit stay, were significantly reduced in the GEN-EPI group. Stepwise logistic regression demonstrated that the only significant predictors of postoperative cardiovascular complications were preoperative congestive heart failure and general anesthesia without epidural analgesia. We conclude that in patients with atherosclerotic vascular disease undergoing arterial reconstructive surgery (a) thromboelastographic evidence of increased platelet-fibrinogen interaction is associated with early postoperative thrombotic events, and (b) epidural anesthesia and analgesia is associated with beneficial effects on coagulation status and postoperative outcome compared with intermittent on-demand opioid analgesia.

Thromboelastography as an indicator of post-cardiopulmonary bypass coagulopathies

Postoperative hemorrhage in patients undergoing open-heart surgery is a major cause of morbidity and mortality. Monitoring of coagulation in these patients has routinely involved the activated clotting time. Thromboelastography is currently used as a monitor of coagulation during liver transplantation. The thromboelastogram, by providing information on the interaction of all the coagulation precursors, gives more clinically useful information on coagulation than that available from the coagulation profile or the activated clotting time alone. This study was done to assess the usefulness of thromboelastography in open-heart surgery. Thirty-eight patients (29 undergoing coronary artery bypass grafting and 9 undergoing valve replacement) were studied with activated clotting time, thromboelastography, and coagulation profiles during three periods: before bypass, during bypass, and after protamine administration. Thromboelastography was a significantly better predictor (87% accuracy) of postoperative hemorrhage and need for reoperation than was the activated clotting time (30%) or coagulation profile (51%). Thromboelastography is easy to use and provides diagnostic data within 30 minutes of blood sampling.

Neurological Complications of Coronary Revascularization

In a series of 3,206 consecutive coronary artery bypass procedures performed between 1976 and 1981, 89 patients died (2.8% mortality) and 32 patients (1%) suffered major neurological syndromes. Among the latter patients, four distinct groups were identified. Group 1 consisted of 10 patients who remained unresponsive after operation. In Group 2 were 10 patients who awakened after operation but had clinical evidence of focal cerebral infarction. Group 3 included 6 patients who were initially intact neurologically but in whom neurological deficits later developed. In Group 4 were 6 patients who had severe mental aberration but no focal neurological deficits. The incidence of coma or focal deficit occurring without a lucid interval (Groups 1 and 2) was 0.62%, and these patients had a 30% mortality. Causative factors were suspected in 70% of the patients in Groups 1 and 2, and included atheromatous embolism, perioperative hypotension, carotid artery occlusive disease and air embolism. The outcome was poor for unresponsive patients, with 70% dying or remaining comatose, but nearly all of the patients with focal deficits or severe mental aberration demonstrated notable improvement.

Surgical Management of Malignant Mesothelioma

The surgical management of 18 patients diagnosed as having malignant mesothelioma is reviewed. Of these patients, 7 received limited treatment--pleurectomy or biopsy. The mean survival was 10 months, and no patient was disease-free at time of death. The other 11 patients were treated by radical extrapleural pneumonectomy. There were 2 long-term, disease-free survivors at 2 and 4 years. Mean survival for the entire group was 15 months, but most patients received good palliation following tumor removal. Surgical procedures for removal of malignant mesothelioma can be accomplished safely and without major morbidity. When possible, radical extrapleural pneumonectomy affords the best palliation and the only opportunity for cure.

Hemodynamic evaluation of a bioprosthetic venous prosthesis

PURPOSE A prosthetic venous valve must be biocompatible and nonthrombogenic and function in the venous circulation. Biocompatibility and thrombogenicity of our prosthesis have been examined in prior animal experiments, and 91% of valve conduits including early prototypes are patent at 3 weeks. However, evaluation of valve function is much more difficult in animals; therefore in this study the function of excised valves was evaluated ex vivo. METHODS Nine bovine jugular vein conduits, each with one bileaflet venous valve, were harvested and placed in a venous flow simulator. Flows and pressures were adjusted to mimic human respiratory and hydrostatic variations. Each valve and conduit was tested for variations in valve diameter and sinus expansion in response to flow. Valve opening and closing times and valve competence were measured in response to pressure changes. After testing, each specimen was glutaraldehyde fixed and assessed a second time. RESULTS Valve orifice area increased in response to flow in both fresh and fixed tissues. Maximum valve orifice area was reduced by fixation (27.7%) at full flows (p < 0.05). Valve sinus dimensions increased in response to increased pressure until maximum expansion was achieved (33 mm Hg). This was reduced 15.3% in fixed tissue (p < 0.05). Valve opening times (at < 1 mm Hg gradient) were slightly longer in fixed compared with fresh tissue (0.43 +/- 0.09 vs 0.41 +/- 0.13 second; p < 0.05). Valve closing times were comparable in both states (0.43 +/- 0.08 vs 0.49 +/- 0.07 second). Three fresh and seven fixed specimens that were subjected to 287 mm Hg back pressure exhibited minimal reflux. CONCLUSIONS Size and availability make the bovine jugular vein valve an ideal venous valve substitute. Glutaraldehyde fixation renders the tissue biocompatible and nonthrombogenic while preserving anatomic integrity and leaflet strength and flexibility. Mounted and stented in a sewing sleeve, this prosthesis could represent the first generally applicable clinical solution to chronic venous insufficiency and venous hypertension.

Inferior vena cava interruption with the hunter-sessions balloon: Eighteen years' experience in 191 cases***

Over a period of 18 years, 191 consecutive patients had interruption of the inferior vena cava with the Hunter-Sessions balloon for complications of deep venous thrombosis and pulmonary embolism. Causes of deep venous thrombosis and pulmonary embolism included the postoperative state (33%), cancer (32%), and stroke (11%). There were 93 females and 98 males; ages ranged from 17 to 90 years (average, 57 years). Indications for placement of the Hunter-Sessions balloon were as follows: contraindication to anticoagulants (33%), anticoagulant complications (24%), pulmonary embolism despite anticoagulants (45%), and others including inferior vena cava thrombus (12%). Sixty-eight percent had clinical phlebitis and 36% had positive venography results. Pulmonary embolism had occurred in 165 patients (86%). It was diagnosed by ventilation-perfusion scanning (75%), angiography (23%), or on clinical grounds (2%) in patients with confirmed deep venous thrombosis. At the time of the procedure 52% were in significant cardiopulmonary distress, and 10% were intubated and on respirators. Transjugular placement was done in 188 patients, and transfemoral placement was performed in three. All All tolerated inferior vena cava interruption. Thirty patients (15%) died while in the hospital an average of 21 days after balloon placement, which was unrelated to the deaths. Follow-up was 45 months. Ninety-four patients are dead, 95 are alive, and the status of two patients is unknown. Twenty-nine of 64 patients (45%) who died after they left the hospital died of cancer. At last follow-up, 75% of patients had legs free of edema and 25% had need for elastic stockings. No malfunction or migration has occurred with the device. No patient had a pulmonary embolism while in the hospital after insertion of the Hunter-Sessions balloon, and no patient died of pulmonary embolism. Late minor pulmonary embolism occurred in three patients.

Transjugular Forceps Retrieval of Catheter Embolus

Intracardiac migration of an intravenous cathether was treated transvenously in 5 patients successfully. Using local anesthesia and fluoroscopic guidance, a bronchoscopy forceps was passed through the right jugular vein to the right atrium and afforded efficient and safe retrieval of the embolus. The direct route to the right atrium provided by the right internal jugular vein and the precise control offerred by the rigid forceps make this the preferred method of retrieval of a transvenous catheter embolus.

Prevention of Air Embolism after Mitral Valve Replacement with a Porcine Heterograft Prosthesis

The production of prosthetic valve incompetence during atriotomy closure is among the operative maneuvers utilized to prevent air embolism in mitral valve replacement. The leaflets of a porcine bioprosthesis may be retracted safely and effectively, thereby producing temporary valve incompetence, by placing three polypropylene sutures through the valve orifice and around the sewing ring to encircle the leaflets. These traction sutures are eaily pulled out through the atriotomy suture line after all air has been displaced from the heart. The technique has been effective, easily accomplished, and without complications.