Transurethral ureterorenolithotripsy using new automated irrigation/suction system controlling pressure and flow compared with standard irrigation: a randomized pilot study

PURPOSE: To compare in a random fashion an automated irrigation/suction pump system with the standard pressurized technique during transurethral ureterorenolithotripsy. PATIENTS AND METHODS: Between July 2001 and December 2001, 47 patients were prospectively included. Prior to randomization, rigid instruments were allocated to 25 patients (group R) and flexible instruments to 22 patients (group F) according to stone location. The groups R and F were then randomized separately, and the pressurized technique was employed in groups R1 and F1, while the automated system was employed in groups R2 and F2. Operative time, amount of liquid consumed, and stone-free rate at the end of the procedure were analyzed. RESULTS: For the entire series, ureteroscopy time using the automated system (mean 42 +/- 17[SD] minutes; range 15-90 minutes) was 35% less than with the pressurized technique (mean 65 +/- 25 minutes; range 20-135 minutes) (P = 0.04 Wilcoxon score). The stone-free rate was significantly higher in groups R2 + F2 (92%) than in groups R1 + F1 (69%) (P = 0.048). CONCLUSION: With the ENDO FMS UROLOGY system, there was a significant reduction in the mean ureteroscopy time: 32% less with the rigid instrument and 53% less with the flexible instrument. This seems to be attributable to a wider working space and highly improved visibility. The integrated suction at constant flow allows efficient evacuation of stone fragments while limiting cavity pressure. These results, obtained on 47 patients, should be confirmed by larger randomized studies.     

Neuromuscular response of young boys versus men during sustained maximal contraction

PURPOSE: This study was designed to compare neuromuscular response between boys and men during sustained maximal voluntary contraction (MVC). METHODS: Fifteen boys (YB, 10.5 +/- 0.9 yr) and 12 men (AM, 21.5 +/- 4.5 yr) participated in the experiment. Arm's cross sectional area (CSA) and maximal force (F(max)) of elbow flexor were measured before subjects performed a 30-s sustained MVC. Mean power frequency (MPF) and muscle fiber conduction velocity (MFCV) were calculated from myoelectric signals of the biceps brachii. F(max)/CSA, MPF, and MFCV changes were expressed by slopes of linear regressions. Maximal MPF (I-MPF) and MFCV (I-MFCV) were derived from the intercept of each regression. RESULTS: AM had significantly greater F(max)/CSA (P < 0.05), I-MPF (P < 0.05), and I-MFCV (P < 0.01) than YB. F(max)/CSA (P < 0.001), MPF (P < 0.001), and MFCV (P < 0.01) declined significantly more for AM than YB. MPF/MFCV ratio increased, i.e., MPF decreased more than MFCV, for both groups but this was significantly (P < 0.001) more pronounced for AM. CONCLUSION: Taken together, those results suggest that more fatigable Type II motor units are involved in men, resulting in greater lactic acid and ions accumulations during fatigue. This difference in muscle's metabolic and ionic state could be responsible for a greater reflex-induced decrease of motor units firing rates in men compared with boys. This firing rate decrease could be explained using the "muscular wisdom" hypothesis and would express a nervous command adaptation to sustain a maximal contraction.     

Halogenated anesthetics reduce interleukin-1beta-induced cytokine secretion by rat alveolar type II cells in primary culture

BACKGROUND: Alveolar epithelial type II (AT II ) cells participate in the intraalveolar cytokine network by secreting cytokines and are widely exposed to volatile anesthetics during general anesthesia. The aim of the current study was to evaluate the effects of halothane, enflurane, and isoflurane on rat AT II cell cytokine secretions in AT II primary cell cultures. METHODS: Alveolar epithelial type II primary cell cultures were obtained from adult rat lungs. AT II cells were stimulated by recombinant murine interleukin-1beta (rmIL-1beta) to mimic an inflammatory response, and immediately exposed for various duration to different concentration of halothane, enflurane, or isoflurane. Interleukin-6, macrophage inflammatory protein-2 (MIP-2), and monocyte chemoattractant protein-1 (MCP-1) protein concentrations were then measured in cell culture supernatants. Recombinant mIL-1beta-stimulated AT II cells exposed to air served as control. RESULTS: Halothane, isoflurane, and enflurane (1 minimum alveolar concentration [MAC], 4 h) decreased rmIL-1beta-stimulated AT II cell secretions of interleukin-6, MIP-2, and MCP-1, but did not modify total protein secretion. Halothane exposure decreased rmIL-1beta-stimulated AT II cell secretions of interleukin-6, MIP-2, and MCP-1 in a dose- and time-dependent manner. Total protein concentrations remained unchanged except AT II 1.5 MAC of halothane, and no cytotoxic effect could be evidenced by lactate dehydrogenase release. These effects were transient as rmIL-1beta-stimulated AT II cell secretions of interleukin-6 and MIP-2 progressively reached control values between 4 and 24 h after the end of halothane exposure. However, MCP-1 inhibition persisted until 24 h. rmIL-1beta-induced MIP-2 and tumor necrosis factor-alpha mRNA expression were decreased by 36 and 24%, respectively, after halothane exposure. CONCLUSIONS: The current study shows that exposure of rmIL-1beta-stimulated AT II cells to volatile anesthetics reversibly alters their cytokine secretion. Therefore, volatile anesthesia, by modulating pulmonary epithelial cell secretion of inflammatory cytokines, might affect the lung inflammatory response.     

Overestimation of Bispectral Index in sedated intensive care unit patients revealed by administration of muscle relaxant

BACKGROUND: Electromyographic activity has previously been reported to elevate the Bispectral Index (BIS) in patients not receiving neuromuscular blockade while under sedation in the intensive care unit. This study aimed to investigate the magnitude of the decrease of BIS following administration of muscle relaxant in sedated intensive care unit patients. METHODS: The authors prospectively investigated 45 patients who were continuously sedated with midazolam and sufentanil to achieve a Sedation-Agitation Scale value equal to 1 and who required administration of muscle relaxant. BIS (BIS version 2.10), electromyography, and acceleromyography at the adductor pollicis muscle were recorded simultaneously before and after neuromuscular blockade. Sixteen of these 45 patients were also studied simultaneously with the new BIS XP. RESULTS: After administration of a muscle relaxant, BIS (67 +/- 19 vs. 43 +/- 10, P < 0.001) and electromyographic activity (37 +/- 9 vs. 27 +/- 3 dB, P < 0.001) significantly decreased. Multiple regression analysis showed that the decrease of BIS following administration of myorelaxant was significantly correlated to BIS and electromyographic baseline values. Using standard BIS range guidelines, the number of patients under light or deep sedation versus general anesthesia or deep hypnotic state was markedly overestimated before administration of myorelaxant (53 vs. 2%, P < 0.001). CONCLUSIONS: The BIS in sedated intensive care unit patients may be lower with paralysis for an equivalent degree of sedation because of high muscular activity. The magnitude of BIS overestimation is significantly correlated to both BIS and electromyographic activity before neuromuscular blockade. The authors conclude that clinicians who determine the amount of sedation in intensive care unit patients only from BIS monitoring may expose them to unnecessary oversedation.     

Treatment of anterior communicating artery aneurysms: complementary aspects of microsurgical and endovascular procedures

OBJECT: Endovascular and surgical treatment must be clearly defined in the management of anterior communicating artery (ACoA) aneurysms. In this study the authors report their recent experience in using a combined surgical and endovascular team approach for ACoA aneurysms, and compare these results with those obtained during an earlier period in which surgical treatment was used alone. Morbidity and mortality rates, causes of unfavorable outcomes, and morphological results were also assessed. METHODS: The prospective study included 223 patients who were divided into three groups: Group A (83 microsurgically treated patients, 1990-1995); Group B (103 microsurgically treated patients, 1996-2000); and Group C (37 patients treated with Guglielmi Detachable Coil [GDC] embolization, 1996-2000). Depending on the direction in which the aneurysm fundus projected, the authors attempted to apply microsurgical treatment to Type 1 aneurysms (located in front of the axis formed by the pericallosal arteries). They proposed the most adapted procedure for Type 2 aneurysms (located behind the axis of the pericallosal arteries) after discussion with the neurovascular team, depending on the physiological status of the patient, the treatment risk, and the size of the aneurysm neck. In accordance with the classification of Hunt and Hess, the authors designated those patients with unruptured aneurysms (Grade 0) and some patients with ruptured aneurysms (Grades I-III) as having good preoperative grades. Patients with Grade IV or V hemorrhages were designated as having poor preoperative grades. By performing routine angiography and computerized tomography scanning, the causes of unfavorable outcome (Glasgow Outcome Scale [GOS] score < 5) and the morphological results (complete or incomplete occlusion) were analyzed. Overall, the clinical outcome was excellent (GOS Score 5) in 65% of patients, good (GOS Score 4) in 9.4%, fair (GOS Score 3) in 11.6%, poor (GOS Score 2) in 3.6%, and fatal in 10.3% (GOS Score 1). Among 166 patients in good preoperative grades, an excellent outcome was observed in 134 patients (80.7%). The combined permanent morbidity and mortality rate accounted for up to 19.3% of patients. The rates of permanent morbidity and death that were related to the initial subarachnoid hemorrhage were 6.2 and 1.5% for Group A, 6.6 and 1.3% for Group B, and 4 and 4% for Group C, respectively. The rates of permanent morbidity and death that were related to the procedure were 15.4 and 1.5% for Group A, 3.9 and 0% for Group B, and 8 and 8% for Group C, respectively. When microsurgical periods were compared, the rate of permanent morbidity or death related to microsurgical complications decreased significantly (Group A, 11 patients [16.9%] and Group B, three patients [3.9%]); Fisher exact test, p = 0.011) from the period of 1990 to 1995 to the period of 1996 to 2000. The combined rate of morbidity and mortality that was related to the endovascular procedure (16%) explained the nonsignificance of the different rates of procedural complications for the two periods, despite the significant decrease in the number of microsurgical complications. Among 57 patients in poor preoperative grade, an excellent outcome was observed in 11 patients (19.3%); however, permanent morbidity (GOS Scores 2-4) or death (GOS Score 1) occurred in 46 patients (80.7%). With regard to the correlation between vessel occlusion (the primary microsurgical complication) and the morphological characteristics of aneurysms, only the direction in which the fundus projected appeared significant as a risk factor for the microsurgically treated groups (Fisher exact test: Group A, p = 0.03; Group B, p = 0.002). The difference between endovascular and microsurgical procedures in the achievement of complete occlusion was considered significant (chi2 = 6.13, p = 0.01). CONCLUSIONS: The direction in which the fundus projects was chosen as the morphological criterion between endovascular and surgical methods. The authors propose that microsurgical clip application should be the preferred option in the treatment of ACoA aneurysms with anteriorly directed fundi and that endovascular packing be selected for those lesions with posteriorly directed fundi, depending on morphological criteria.     

Microvascular free-tissue transfer for traumatic defects of the upper extremity: a 25-year experience

Microvascular free-tissue transfer has been a major advance in the treatment of complex traumatic defects of the upper extremity. One hundred and fifty microvascular free-tissue transfers were performed in 133 patients with complex traumatic upper extremity defects at Bellevue Hospital Center from 1976 to 2000. The indication for microvascular free tissue transfers was exposure of vital structure (81 percent), bone defect (11 percent), and functional deficit (8 percent). The parascapular region was the most common donor site used (26 percent). Microvascular free-tissue transfer was performed either emergently at the time of injury (9.3 percent), during days 1 to 5 post injury (19.3 percent), during days 6 to 21 (19.3 percent), or after day 21 (52 percent). The overall flap failure rate was 9 percent. A decreased incidence of flap failure was observed in patients treated from 6 to 21 days post injury (3 percent p<0.05). The most common acute complication was infection at the recipient site, observed in 14 percent of patients overall. A decreased incidence of recipient-site infection was seen in patients who received free flaps at days 6 to 21 (3 percent; p<0.05). In long-term follow-up, the incidences of osteomyelitis and nonunion were lowest in patients treated from 6 to 21 days post injury (0.0 percent and 11 percent, respectively; p<0.05). During the last 10 years, the timing of reconstruction has been altered, and now preferentially microvascular free flaps are performed 6 to 21 days post injury. The treatment algorithm has been simplified and now only four different flaps are used in the majority of patients (70 percent). With this, the authors have witnessed a decrease in failure rates from 11 percent to 4 percent, a decrease in recipient-site infections from 16 percent to 10 percent and a decrease in osteomyelitis from 12 percent to 4 percent. The preferred timing for microvascular free-tissue transfers to the upper extremity is concluded to be 6 to 21 days post injury.