Use of microvascular Doppler sonography in aneurysm surgery on the anterior choroidal artery.
Anterior choroidal artery (AChA) syndrome is still one of the most serious complications of the clipping of internal carotid artery aneurysms. No monitoring method can detect ischemia in the area of the AChA during surgery. This artery may be obstructed when a clip is applied to the neck of the aneurysm, and patency is sometimes difficult to confirm by microscopy because of the artery's small size and site of origin (usually behind the internal carotid artery as viewed surgically). However, microvascular Doppler sonography (MVDS) can detect flow instantaneously even in such a small vessel. In our series, AChA syndrome occurred in three of 19 patients treated for AChA aneurysm before the introduction of MVDS, but only one of 19 patients treated with the aid of this device. In that patient, one of the two AChA branches was intentionally sacrificed by applying a clip to the prematurely ruptured aneurysm. MVDS detected hypoperfusion of the AChA after clipping in five other patients, and so the clip was readjusted to preserve AChA flow. Use of MVDS is very effective to prevent inadvertent injury to the AChA during aneurysm surgery on this artery. (+info)
Noninvasive localization procedures in ectopic hyperfunctioning parathyroid tumors.
In primary hyperparathyroidism (pHPT), parathyroidectomy is the treatment of choice, but anatomic variations of ectopic glands may cause surgical failure. Reliable preoperative noninvasive localization procedures would have a positive impact on the operative time and increase recovery rate. We retrospectively evaluated 186 patients with pHPT who were studied before successful parathyroidectomy by double tracer scintigraphy (99mTc-pertechnetate+201TI chloride or 99mTc-pertechnetate +99mTc-sestamibi, 160 patients), ultrasonography (148 patients) and computerized tomography (CT) scan (92 patients). During bilateral neck exploration, 159 (85.5%) single adenomas, 6 (3.2%) parathyroid carcinomas, and 3 (1.6%) double adenomas were found. Moreover, 18 (9.7%) patients had diffuse chief cells parathyroid hyperplasia. Removed parathyroid glands were in ectopic sites in 41 (22.0%) cases, mainly localized in the upper mediastinum or behind the esophagus. The overall sensitivity was 83.5 and 85.2% for 99mTc-pertechnetate+201TI chloride and 99mTc-pertechnetate+99mTc-sestamibi scintigraphy respectively, 80.4% for CT scan and 81.1% for ultrasonography. In patients with ectopic glands, sensitivity was 81.2, 79.5, 73.3 and 81.6% respectively. In 36 out of 41 patients with ectopic glands in whom the removed parathyroids were correctly localized, mean operative time was 95 min, and in 5 patients without preoperative localization it was 260 min. In conclusion, in pHPT, preoperative localization of an enlarged parathyroid is helpful, especially in ectopic adenomas and in anatomic variations in location, and it has been proved to reduce operative time and morbidity rate. (+info)
Plasma concentration of fentanyl with xenon to block somatic and hemodynamic responses to surgical incision.
BACKGROUND: Although anesthesia with xenon has been supplemented with fentanyl, its requirement has not been established. This study was conducted to determine the plasma concentrations of fentanyl necessary to suppress somatic and hemodynamic responses to surgical incision in 50% patients in the presence of 0.7 minimum alveolar concentration (MAC) xenon. METHODS: Twenty-five patients were allocated randomly to predetermined fentanyl concentration between 0.5 and 4.0 ng/ml during 0.7 MAC xenon anesthesia. Fentanyl was administered using a pharmacokinetic model-driven computer-assisted continuous infusion device. At surgical incision each patient was monitored for somatic and hemodynamic responses. A somatic response was defined as any purposeful bodily movement. A positive hemodynamic response was defined as a more than 15% increase in heart rate or mean arterial pressure more than the preincision value. The concentrations of fentanyl to prevent somatic and hemodynamic responses in 50% of patients were calculated using logistic regression. RESULTS: The concentration of fentanyl to prevent a somatic response to skin incision in 50% of patients in the presence of 0.7 MAC xenon was 0.72 +/- 0.07 ng/ml and to prevent a hemodynamic response was 0.94 +/- 0.06 ng/ml. CONCLUSIONS: Comparing these results with previously published results in the presence of 70% nitrous oxide, the fentanyl requirement in xenon anesthesia is smaller than that in the equianesthetic nitrous oxide anesthesia. (+info)
Midterm follow-up of necrotic bleb excision and advancement of the fornical conjunctiva.
Mitomycin C has improved the success rate of glaucoma filtering surgery in patients at high risk for surgical failure. However chronic hypotony is marked by decreased vision and a late-onset leaking bleb after filtration surgery using mitomycin C. Bleb excision and conjunctival advancement is the method of choice to repair bleb leakage and chronic hypotony. Five eyes from five patients were received glaucoma filtration surgery with topical mitomycin C. All of the patients' blebs were avascular and transparent. The reasons for bleb excision were two spontaneous bleb leaks, two traumatic bleb leaks and one case of severe irritation. The mean follow-up period was 18.4 +/- 8.3 months (ten to 29 months). Cataract surgery was combined in one eye. Postoperative intraocular pressure (IOP) increased from 2.3 +/- 1.5 mmHg to 9.5 +/- 3.7 mmHg at nine months postoperatively in four eyes. It went from 28 mmHg to 40 mmHg in one patient with uveitis, for whom a second trabeculectomy with mitomycin C; 0.4 mg/ml for 3 minutes, was performed. After surgery, IOP decreased to 4 mmHg in three months. Postoperative visual acuity improved four snellen lines in three eyes. A partially avascular bleb recurred in three eyes, a corneal bleb in one eye and blepharoptosis, which disappeared spontaneously at four months postoperatively, in one eye. Necrotic bleb excision and advancement of fornical conjunctiva were useful methods to increase IOP and to improve visual acuity for the patient experiencing irritation symptoms, and for leaking blebs, and hypotonic maculopathy. (+info)
Predictors of hypothermia during spinal anesthesia.
BACKGROUND: Body temperature often is ignored during regional anesthesia, despite evidence that hypothermia occurs commonly. Because hypothermia is associated with adverse clinical outcomes, it is important to recognize predictors of hypothermia and to monitor and control body temperature in patients at risk. The current study was designed to determine the predictors of core hypothermia in patients receiving spinal anesthesia for radical retropubic prostatectomy. METHODS: Forty-four patients undergoing radical retropubic prostatectomy were studied. A lumbar intrathecal injection of 18-22 mg bupivacaine, 0.75%, with 20 microg fentanyl was given. No active warming measures were used other than intravenous fluid warming. The following clinical variables were assessed as potential predictors of core (tympanic) temperature at admission to the postanesthesia care unit: duration of surgery, average ambient operating room temperature, body habitus, age, and spinal blockade level. RESULTS: The mean core temperature at admission to the postanesthesia care unit was 35.1 +/- 0.6 degrees C (range, 33.6-36.3 degrees C). Duration of surgery, ambient operating room temperature, and body habitus were not predictors of hypothermia. A high level of spinal blockade and increasing age were predictors of hypothermia. For each incremental increase in block level, core temperature decreased by 0.15 degrees C, and for each increase in age, core temperature decreased by 0.3 degrees C. CONCLUSIONS: Although high-level spinal blockade has been associated with decreased thermoregulatory thresholds, no previous study has shown that a higher level of blockade is associated with a greater magnitude of core hypothermia in the clinical setting. As with general anesthesia, advanced age is associated with hypothermia during spinal anesthesia. (+info)
Activation of mitogen-activated protein kinases in human heart during cardiopulmonary bypass.
Mitogen-activated protein kinases (MAPKs) have been shown to be activated in both in vitro and in vivo models of cardiac tissue in response to ischemia/reperfusion injury. We investigated whether MAPKs are activated in human heart during coronary artery bypass grafting (CABG) surgery. During elective CABG surgery of 8 patients, 3 right atrial appendage biopsies were obtained at baseline, at the end of cross-clamping, and after coronary reperfusion. The expression of the p38-MAPK, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinases (ERK1/2) MAPKs was not altered during CABG. The phosphorylation and activation of both ERK1/2 and p38-MAPK were increased approximately 2-fold by ischemia and even more (8- and 4-fold, respectively) by reperfusion. Although the ischemic period did not result in a significant activation of JNK, an approximately 6-fold increase in JNK activity could be observed after reperfusion. In conclusion, distinct activation patterns of ERK1/2, p38, and JNK MAPKs can be observed in human heart during CABG. (+info)
Intracerebral hemorrhage after liver transplantation.
We report 5 patients with intracerebral hemorrhage after orthotopic liver transplantation (OLT) and identify the possible risk factors. Between November 1991 and April 1999, 75 adult patients received 77 orthotopic liver transplants at Queen Mary Hospital, Hong Kong. Five patients (6.5%) developed intracerebral hemorrhage postoperatively. Clinical and laboratory data were reviewed, and potential risk factors were analyzed. The 5 patients developed intracerebral hemorrhage within 40 days (range, 1 to 37 days; median, 4 days) after OLT. The mortality rate was 80% (4 of 5 patients). The intraoperative blood transfusion volume (median, 17,200 mL; range, 15,750 to 30,360 mL) administered to patients who developed intracerebral hemorrhage postoperatively was significantly greater than that (median, 6,990 mL; range, 1,840 to 22,680 mL) for patients without the complication (P =.0008). Massive intraoperative transfusion (>15,000 mL) was required in all 5 patients (100%) with intracerebral hemorrhage but only 9 of 72 patients (12.5%) in the other group (P =.0001). Four of 5 patients (80%) with intracerebral hemorrhage had intraoperative hypotension compared with 7 of 72 patients (9.7%) in the other group (P =.001). No significant difference was found in age, prothrombin time (PT), activated partial thromboplastin time (APTT), incidence of hypertension, bleeding at extracerebral sites, cyclosporine A neurotoxicity, thrombocytopenia, hemodialysis, and sepsis between the patients with and without intracerebral bleeding. However, the median cumulative score of coagulation parameters (PT, APTT, platelet count) was significantly greater in the group with than without intracerebral bleeding (median score, 3 v 1; P =.023). Intracerebral hemorrhage is 1 of the most disastrous complications after OLT. Intraoperative hypotension, massive intraoperative transfusion, and coagulopathy may be correlated with this complication. (+info)
Intraperitoneal and retroperitoneal carbon dioxide insufflation evoke different effects on caval vein pressure gradients in humans: evidence for the starling resistor concept of abdominal venous return.
BACKGROUND: The authors hypothesized that intraperitoneal and retroperitoneal carbon dioxide insufflation during surgical procedures evoke markedly different effects on the venous low-pressure system, induce different inferior caval vein pressure gradients at similar insufflation pressures, and may provide evidence for the Starling resistor concept of abdominal venous return. METHODS: Intra- and extrathoracic caval vein pressures were measured using micromanometers during carbon dioxide insufflation at six cavity pressures (baseline and 10, 15, 20, and 24 mmHg and desufflation) in 20 anesthetized patients undergoing laparoscopic (supine, n = 8) or left (n = 6) or right (n = 6) retroperitoneoscopic (prone position) surgery. Intracavital, esophageal, and gastric pressures also were assessed. Data were analyzed for insufflation pressure-dependent and group effects by one-way and two-way analysis of variance for repeated measurements, respectively, followed by the Newman-Keuls post hoc test (P < 0.05). RESULTS: Intraperitoneal, unlike retroperitoneal, insufflation markedly increased, in an insufflation pressure-dependent fashion, the inferior-to-superior caval vein pressure gradient (P < 0.00001) at the level of the diaphragm. In contrast to what was observed with retroperitoneal insufflation, transmural intrathoracic caval vein pressure increased at 10 mmHg insufflation pressure, but the increase flattened with an insufflation pressure of more than 10 mmHg, and pressure decreased with an inflation pressure of 20 mmHg (P = 0.0397). These data are consistent with a zone 2 or 3 abdominal vascular condition during intraperitoneal and a zone 3 abdominal vascular condition during retroperitoneal insufflation. CONCLUSIONS: Intraperitoneal but not retroperitoneal carbon dioxide insufflation evokes a transition of the abdominal venous compartment from a zone 3 to a zone 2 condition, presumably impairing venous return, supporting the Starling resistor concept of abdominal venous return in humans. (+info)