Giant coronary artery aneurysm with coronary arteriovenous fistula draining into the coronary sinus.

A 77-year-old patient suffering from a giant right coronary artery aneurysm with coronary arteriovenous fistula was admitted to our hospital. The fistula could not be documented preoperatively by computed tomography or coronary angiography but was documented intraoperatively by transesophageal echocardiography (TEE). However, TEE was unable to visualize the draining site of the fistula. Direct palpation by the surgeon ultimately confirmed that the fistula was draining into the coronary sinus. The fistula was closed and the volume of the aneurysm reduced by partial resection. The postoperative course of the patient was uneventful. Giant aneurysms occasionally displace cardiac structures. In such cases, combined imaging technologies, including TEE, may be needed for precise assessment of the giant aneurysm and fistula.

Association between cerebrovascular carbon dioxide reactivity and postoperative short-term and long-term cognitive dysfunction in patients with diabetes mellitus.

PURPOSE: Our intent was to identify whether cerebrovascular CO(2) reactivity in diabetic patients is a risk factor for postoperative cognitive dysfunction after coronary artery bypass graft (CABG) surgery. METHODS: One hundred twenty-four diabetic patients undergoing elective CABG were studied and analyzed. Diabetic patients were divided into three groups: normal CO(2) reactivity group (above 5%/mmHg), medium CO(2) reactivity group (between 5 and 3%/mmHg), or impaired CO(2) reactivity group (below 3%/mmHg). After the induction of anesthesia and before the start of surgery, cerebrovascular CO(2) reactivity was measured for all patients. Hemodynamic parameters (arterial and jugular venous blood gas values) were measured during cardiopulmonary bypass. All patients underwent a battery of neurological and neuropsychological tests the day before surgery, 7 days after surgery, and 6 months after surgery. RESULTS: At 7 days, the rate of cognitive dysfunction in the impaired CO(2) group was higher than in the other three groups (normal, 30%; medium, 25%; impaired, 57%; *P < 0.01 compared with the other groups). In contrast, at 6 months postoperatively, no significant difference in the rate of cognitive dysfunction was found among the three groups. Age, hypertension, CO(2) reactivity, the duration for which jugular venous oxygen saturation (SjvO(2)) was less than 50%, ascending aorta atherosclerosis, diabetic retinopathy, and insulin therapy were independent predictors of short-term cognitive dysfunction in diabetic patients, and HbA1c, diabetic retinopathy, and insulin therapy were independent predictors of long-term cognitive dysfunction in diabetic patients. CONCLUSIONS: We found that impaired cerebrovascular CO(2) reactivity was associated with postoperative short-term cognitive dysfunction in diabetic patients.

Time course of changes in cerebral blood flow velocity after tourniquet deflation in patients with diabetes mellitus or previous stroke under sevoflurane anesthesia.

We observed an increase in mean middle cerebral artery blood flow velocity (V(mca)) after tourniquet deflation during orthopedic surgery under sevoflurane anesthesia in patients with diabetes mellitus or previous stroke. Eight controls, seven insulin-treated diabetic patients, and eight previous stroke patients were studied. Arterial blood pressure, heart rate, V(mca), arterial blood gases, and plasma lactate levels were measured every minute for 10 min after tourniquet release in all patients. V(mca) was measured using a transcranial Doppler probe. V(mca) in all three groups increased after tourniquet deflation, the increase lasting for 4 or 5 min. However, the degree of increase in V(mca) in the diabetic patients was smaller than that in the other two groups after tourniquet deflation (at 2 min after tourniquet deflation: control 58.5 ± 3.3, previous stroke 58.4 ± 4.6, diabetes 51.7 ± 2.3; P < 0.05 compared with the other two groups). In conclusion, the degree of increase in V (mca) in diabetic patients is smaller than that in controls and patients with previous stroke.

Preoperative depression is a risk factor for postoperative short-term and long-term cognitive dysfunction in patients with diabetes mellitus.

PURPOSE: To identify whether the presence of preoperative depression in patients with diabetes mellitus is a risk factor for postoperative cognitive dysfunction after coronary artery bypass graft (CABG) surgery. METHODS: Data from 90 patients with diabetes mellitus undergoing elective CABG were analyzed. Hemodynamic data (arterial and jugular venous blood gas values) were measured during cardiopulmonary bypass. Preoperatively, all patients were given the 21-item Beck depression inventory to identify the presence of depression. In addition, all patients underwent a battery of neurological and neuropsychological tests the day before surgery, 7 days after surgery, and 6 months after surgery. RESULTS: The rate of cognitive dysfunction was 50% at 7 days and 23% at 6 months after surgery. Age, hypertension, presence of depression, duration of SjvO(2) ≤ 50%, ascending aorta atherosclerosis, diabetic retinopathy, and insulin therapy were independent predictors of short-term cognitive dysfunction, whereas HbA1c, diabetic retinopathy, insulin therapy, and presence of depression were independent predictors of long-term cognitive dysfunction. CONCLUSIONS: We found that the presence of depression preoperatively is associated with short-term and long-term postoperative cognitive dysfunction in patients with diabetes mellitus.

Comparison of the effects of vasopressin and norepinephrine on organ perfusion during septic shock in streptozotocin-induced diabetic rats.

PURPOSE: The purpose of this study was to compare the effects of norepinephrine (NE) and vasopressin on systemic hemodynamics, renal and mesenteric artery blood flow, inflammatory response and inducible nitric oxide synthase (iNOS) activity during endotoxin shock in streptozotocin-induced diabetic rats. METHODS: The study was designed to include three sets of experiments: (1) measurement of changes in systemic hemodynamics and mesenteric and renal artery blood flow; (2) measurement of biochemical variables; and (3) measurement of iNOS activity in the mesenteric artery. Systemic hemodynamics, regional artery blood flow changes and biochemical variables were assessed before treatment and 1, 2 and 3 h after treatment. RESULTS: Vasopressin, but not NE, prevented the decreases in aortic blood flow, but did not restore mesenteric artery blood flow. In addition, vasopressin partially restored renal artery blood flow in diabetic rats. Plasma nitrite levels and iNOS activity in the mesenteric artery were elevated after intravenous LPS in diabetic rats. Endotoxin-induced decreases in mesenteric arterial blood flow were partially restored by vasopressin with nonselective NOS inhibitor, N G-nitro-l-arginine methyl ester (l-NAME), in diabetic rats. Moreover, l-NAME prevented increases in plasma nitrite levels and iNOS activity in the mesenteric artery. In contrast, endotoxin-induced decreases in renal arterial blood flow were partially restored by vasopressin with l-NAME, but not by NE in diabetic rats. CONCLUSIONS: Nitric oxide may be one possible contributor to reduced sensitivity of the mesenteric and renal arteries to vasopressin during septic shock in streptozotocin-induced diabetic rats.

The comparative effects of equipotent Bispectral Index dosages of propofol and sevoflurane on cerebrovascular carbon dioxide reactivity in elderly patients.

STUDY OBJECTIVES: To compare the effects of equipotent Bispectral Index (BIS) doses of propofol and sevoflurane on cerebrovascular carbon dioxide (CO(2)) reactivity in elderly patients. DESIGN: Prospective, randomized, controlled study. SETTING: University Hospital. PATIENTS: 30 consecutive elderly patients (older than 70 yrs of age) scheduled for elective orthopedic, cardiac, or thoracic surgery. INTERVENTIONS: Anesthesia was maintained with either sevoflurane or propofol along with 33% oxygen and 67% nitrous oxide. A BIS monitor was used. Sevoflurane and propofol dosages were controlled to maintain BIS values at target levels of 40-45. MEASUREMENTS: A 2.5-MHz pulsed transcranial Doppler (TCD) probe was used to measure mean blood flow velocity in the middle cerebral artery (Vmca). After establishing baseline values of Vmca, end-tidal CO(2) was increased by decreasing ventilatory frequency by 4-8 breaths/min. MAIN RESULTS: Equipotent doses of 2.25% sevoflurane and 6.61 mg/kg/hr of propofol were required to maintain BIS values at target levels. Baseline blood pressure (BP), BP at hypercapnia, baseline PaCO(2), baseline PaCO(2) at hypercapnia, and pulsatile index were essentially identical between the groups. Absolute and relative CO(2) reactivities in the sevoflurane groups were higher than those in the propofol groups (absolute CO(2) reactivity: 3.2 +/- 0.2* vs. 2.2 +/- 0.3 cm/sec/mmHg; relative CO(2) reactivity: 9.4 +/- 0.3* vs. 7.8 +/- 0.3 cm/sec/mmHg; *P < 0.01 vs. propofol group). CONCLUSIONS: In elderly patients, hypercapnia has less effect on cerebral circulation during propofol anesthesia than with sevoflurane.

Evaluation of cerebrovascular carbon dioxide reactivity in patients with diabetes mellitus under sedative doses of propofol.

The present study compared cerebrovascular CO2 reactivity in diabetic patients on different treatment modalities under sedative doses of propofol. Fifteen patients with diabetes mellitus (on three different antidiabetic treatment modalities) who required mechanical ventilation during intensive care therapy were studied, sedation during mechanical ventilation being maintained using propofol. As controls, 6 patients without diabetes were monitored. A 2.5-MHz pulsed transcranial Doppler probe was attached to the head of the patient at the right temporal window for continuous measurement of mean blood flow velocity in the middle cerebral artery (Vmca). After establishing baseline values of Vmca and cardiovascular hemodynamics, end-tidal CO2 was decreased by increasing ventilatory frequency by 5-8 breaths.min(-1). Values for absolute and relative CO2 reactivity in insulintreated patients were lower than those in the other three groups (absolute CO2 reactivity [means +/- SD]: control, 3.1 +/- 0.6 cm.s(-1).mmHg(-1), diet, 3.8 +/- 1.4 cm.s(-1) x mmHg(-1); oral antidiabetic drug 3.2 +/- 0.9 cm x s(-1) x mmHg(-1); insulin, 1.1 +/- 0.6 cm x s(-1) x mmHg(-1); P = 0.002).The present study shows that insulin-treated diabetic patients probably have lower cerebrovascular CO2 reactivity under propofol anesthesia than control patients or diabetics treated with dietary therapy or oral hypoglycemics.

Percutaneous radiofrequency lumbar facet rhizotomy guided by computed tomography fluoroscopy.

X-ray fluoroscopy-guided percutaneous radiofrequency facet rhizotomy is used to treat chronic low back pain. The traditional fluoroscopic approach to the medial branch of the posterior rami, however, is associated with a small incidence of complications. We describe a new method for radiofrequency lumbar facet rhizotomy in which computed tomography (CT) fluoroscopy is used to guide needle placement. Three patients with chronic intractable low back pain underwent CT fluoroscopy-guided percutaneous facet rhizotomy. After the safest and shortest route to the target site was determined on the CT image, the needle was advanced along the predetermined route under real-time CT fluoroscopy. When the needle tip was located at the target site, electrical stimulation was applied to verify proper electrode placement. After confirming the clinical effect and lack of complications under test block with a local anesthetic, denervation was performed using radiofrequency current. Pain scores of all patients were reduced after the procedure without any complications such as paralysis or neuritic pain. None of the patients complained of severe discomfort during the procedure. CT fluoroscopy-guided percutaneous lumbar facet rhizotomy appears to be safe, fast, and effective for patients with lumbar facet pain.