Preoperative angiographic score and intraoperative flow as predictors of the mid-term patency of infrapopliteal bypass grafts.
OBJECTIVES: preoperative angiographic characteristics of the outflow tract have emerged as a predictive factor for the outcome of infrapopliteal reconstructions. Direct flow measurement can be routinely performed intraoperatively, but little is known regarding its impact on graft outcome. The present study was undertaken to compare the value of these parameters in predicting the mid-term patency of infrapopliteal bypass grafts. DESIGN: retrospective clinical study. PATIENTS: 172 infrapopliteal reconstructions using autogenous vein were performed, of which 92 had a crural and 80 a pedal recipient artery. METHODS: the preoperative angiogram was scored according to the SVS/ISCVS Ad Hoc Committee. At the end of the operation flow was measured with a transit-time flowmeter. Follow-up consisted of pressure measurements and duplex scanning. RESULTS: the runoff score had no impact on femorocrural graft patency. For pedal grafts there was a tendency for inferior outcome with high runoff score, as the 1-year assisted primary patency for grafts with a completely occluded pedal arch was 11% compared with 52% for grafts with lower scores (p=0.056). Both intraoperative volume graft flow and maximum flow capacity had a highly significant influence on the outcome on crural reconstructions on univariate analysis. For pedal reconstructions only a a severely reduced maximum flow capacity after injection of papaverin was associated with an adverse outcome. Multivariate analysis revealed that maximum flow capacity was an independent significant factor affecting patency of femoroinfrapopliteal grafts (relative risk=0.53 per 30 ml/min increase, p<0.001). The runoff score was also a weak independent predictor of 1-year assisted primary patency in these grafts (relative risk=1.9 for a score >4 in crural and a score >5.5 in pedal grafts, p=0.036). CONCLUSIONS: a completely occluded pedal arch in preoperative angiography was associated with poor infrapopliteal bypass outcome. Graft flow and maximal flow capacity are good predictors of the 1-year graft patency of femorocrural bypasses. (+info)
Is intra-operative gamma probe detection really necessary for inguinal sentinel lymph node biopsy?
CONTEXT: Sentinel node (SN) biopsy has changed the surgical treatment of malignant melanoma. The literature has emphasized the importance of gamma probe detection (GPD) of the SN. OBJECTIVE: Our objective was to evaluate the efficacy of patent blue dye (PBD) and GPD for SN biopsy in different lymphatic basins. DESIGN: Patients with cutaneous malignant melanoma in stages I and II were submitted to biopsy of the SN, identified by PBD and GPD, as part of a research project. SETTING: Patients were seen at Hospital Sao Paulo by a multidisciplinary group (Plastic Surgery Tumor Branch, Nuclear Medicine and Pathology). PATIENTS: 64 patients with localized malignant melanoma were studied. The median age was 46.5 years. The primary tumor was located in the neck, trunk or extremities. INTERVENTIONS: Preoperative lymphoscintigraphy, lymphatic mapping with PBD and intraoperative GPD was performed on all patients. The SN was examined by conventional and immunohistochemical staining. If the SN was not found or contained micrometastases, only complete lymphadenectomy was performed. MAIN MEASUREMENTS: The SN was identified by PBD if it was blue-stained, and by GPD if demonstrated activity five times greater than the adipose tissue of the neighborhood. RESULTS: Seventy lymphatic basins were explored. Lymphoscintigraphy showed ambiguous drainage in 7 patients. GPD identified the SN in 68 basins (97%) and PBD in 53 (76%). PBD and GPD identified SN in 100% of the inguinal basins. For the remaining basins both techniques were complementary. A metastatic SN was found in 10 basins. Three patients with negative SN had recurrence (median follow-up = 11 months). CONCLUSION: Although both GPD and PBD are useful and complementary, PBD alone identified the SN in 100% of the inguinal lymphatic basins. (+info)
Tranexamic acid administration after cardiac surgery: a prospective, randomized, double-blind, placebo-controlled study.
BACKGROUND: Many different doses and administration schemes have been proposed for the use of the antifibrinolytic drug tranexamic acid during cardiac surgery. This study evaluated the effects of the treatment using tranexamic acid during the intraoperative period only and compared the results with the effects of the treatment continued into the postoperative period. METHODS: Patients undergoing elective cardiac surgery with use of cardiopulmonary bypass (N = 510) were treated intraoperatively with tranexamic acid and then were randomized in a double-blind fashion to one of three postoperative treatment groups: group A: 169 patients, infusion of saline for 12 h; group B: 171 patients, infusion of tranexamic acid, 1 mg x kg(-1) x h(-1) for 12 h; group C: 170 patients, infusion of tranexamic acid, 2 mg x kg(-1) x h(-1) for 12 h. Bleeding was considered to be a primary outcome variable. Hematologic data, allogeneic transfusions, thrombotic complications, intubation time, and intensive care unit and hospital stay duration also were evaluated. RESULTS: No differences were found among groups regarding postoperative bleeding and outcomes; however, the group treated with 1 mg x kg(-1) x h(-1) tranexamic acid required more units of packed red blood cells because of a significantly lower basal value of hematocrit, as shown by multivariate analysis. CONCLUSIONS: Prolongation of treatment with tranexamic acid after cardiac surgery is not advantageous with respect to intraoperative administration alone in reducing bleeding and number of allogeneic transfusions. Although the prevalence of postoperative complications was similar among groups, there is an increased risk of procoagulant response because of antifibrinolytic treatment. Therefore, the use of tranexamic acid during the postoperative period should be limited to patients with excessive bleeding as a result of primary fibrinolysis. (+info)
Perioperative activation of hemostasis in vascular surgery patients.
BACKGROUND: Perioperative activation of hemostasis could play an important role in the occurrence of postoperative cardiac events. The authors conducted a prospective study to assess platelet function, coagulation, and fibrinolysis status during and after infrarenal aortic surgery. METHODS: Seventeen patients were studied. Excluded were patients with preoperative coagulopathies or liver disease, or cardiac or renal insufficiency; patients receiving anticoagulant treatment, antiplatelet agents, nonsteroidal antiinflammatory agents, fresh frozen plasma, or platelet concentrates; and patients undergoing reoperation and septic patients. Blood samples were drawn before induction (T1), 1 h after incision (T2), 1 h after extubation (T3), 24 h postoperatively (T4), 48 h postoperatively (T5), and at day 7 (T6). The following tests were performed: platelet count, platelet aggregation, platelet flow cytometry for CD62 and CD63, usual coagulation tests, thrombin--antithrombin complexes, plasminogen activator inhibitor 1. RESULTS: A significant increase of adenosine diphosphate--induced platelet aggregation was observed postoperatively at T4 and T5. This was not associated with a change of flow cytometry profile. No increase of thrombin--antithrombin complex levels was observed. A higher fibrinogen rate was detected at T5 and T6. Greater amounts of plasminogen activator inhibitor 1 were detected at T3 and T4. Thus, thrombin generation was limited and fibrinolysis was impaired postoperatively. Platelets were not activated in the postoperative period, as shown by flow cytometry, but were prone to be activated, as shown by aggregation studies. CONCLUSION: The association of more easily activated platelets with a higher fibrinogen rate and a temporary shut down of fibrinolysis during the early postoperative period may indicate an increased thrombotic risk in patients undergoing major vascular surgery. (+info)
An investigation of learning during propofol sedation and anesthesia using the process dissociation procedure.
BACKGROUND: Many studies have shown that patients may remember words learned during apparently adequate anesthesia. Performance on memory tests may be influenced by explicit and implicit memory. We used the process dissociation procedure to estimate implicit and explicit memory for words presented during sedation or anesthesia. METHODS: We investigated intraoperative learning in 72 women undergoing pervaginal oocyte collection during propofol and alfentanil infusion. One word list was played once before infusion, another was played 10 times during surgery. Venous blood was taken for propofol assay at the end of the intraoperative list. Behavioral measures of anesthetic depth (eyelash reflex, hand squeeze response to command) were recorded and used to adjust the dose of anesthetic where clinically appropriate. On recovery, memory was assessed using an auditory word stem completion test with inclusion and exclusion instructions. RESULTS: The mean blood propofol concentration was 2.5 microg/ml (median, 2.3 microg/ml; range, 0.7-6.1 microg/ml). Mean alfentanil dose was 2.1 mg (median, 2.0 mg; range, 1.2-3.4 mg). Comparison of target and distractor hits in the inclusion condition showed memory for preoperative words only. However, the process dissociation procedure estimates showed explicit (mean, 0.18; P < 0.001) and implicit (mean, 0.05; P < 0.05) memory for the preoperative words, and a small amount of explicit memory for the intraoperative words (mean, 0.06; 95% confidence interval, 0.01-0.10). Memory performance did not differ between the 17 patients who consistently responded to command and eyelash reflex and the 32 patients who remained unresponsive. Blood propofol concentration and alfentanil dose did not correlate with memory for the intraoperative list. CONCLUSIONS: There was no unprompted recall of surgery, but the process dissociation procedure showed memory for words presented during surgery. This memory was apparently explicit but did not correlate with the measures of depth of anesthesia used. (+info)
Ion channel remodeling is related to intraoperative atrial effective refractory periods in patients with paroxysmal and persistent atrial fibrillation.
BACKGROUND: Sustained shortening of the atrial effective refractory period (AERP), probably due to reduction in the L-type calcium current, is a major factor in the initiation and maintenance of atrial fibrillation (AF). We investigated underlying molecular changes by studying the relation between gene expression of the L-type calcium channel and potassium channels and AERP in patients with AF. METHODS AND RESULTS: mRNA and protein expression were determined in the left and right atrial appendages of patients with paroxysmal (n=13) or persistent (n=16) AF and of 13 controls in sinus rhythm using reverse transcription polymerase chain reaction and slot-blot, respectively. The mRNA content of almost all investigated ion channel genes was reduced in persistent but not in paroxysmal AF. Protein levels for the L-type Ca(2+) channel and 5 potassium channels (Kv4.3, Kv1.5, HERG, minK, and Kir3.1) were significantly reduced in both persistent and paroxysmal AF. Furthermore, AERPs were determined intraoperatively at 5 basic cycle lengths between 250 and 600 ms. Patients with persistent and paroxysmal AF displayed significant shorter AERPs. Protein levels of all ion channels investigated correlated positively with the AERP and with the rate adaptation of AERP. Patients with reduced ion channel protein expression had a shorter AERP duration and poorer rate adaptation. CONCLUSIONS: AF is predominantly accompanied by decreased protein contents of the L-type Ca(2+) channel and several potassium channels. Reductions in L-type Ca(2+) channel correlated with AERP and rate adaptation, and they represent a probable explanation for the electrophysiological changes during AF. (+info)
Multistate utilization, processes, and outcomes of carotid endarterectomy.
OBJECTIVES: The purpose of this study was to describe variation in utilization, care processes, and outcomes for carotid endarterectomy (CEA) procedures in 10 states. METHODS: We reviewed the medical records of Medicare patients who underwent 10,561 CEA procedures between June 1, 1995, and May 31, 1996, in 10 different states to determine indications, care processes, and outcomes. This study also included medical record review of hospital readmissions within 30 days of the procedure and identification of out-of-hospital deaths from the Medicare beneficiary files. RESULTS: Utilization rates of CEA varied from 25.7 to 38.4 procedures per 10,000 Medicare beneficiaries among states. The overall combined event rate (30-day stroke or mortality) was 5.2% for primary CEA alone (n = 9945). The mortality rate was 1.5%, and the nonfatal stroke rate was 3.7%. Combined event rates (CEA alone) by surgical indication were 7.7% for stroke (n = 1037), 7.4% for transient ischemic attack (n = 1304), 5.3% for nonspecific symptoms (n = 3713), and 3.7% for asymptomatic patients (n = 3891). The combined event rates (CEA alone) among states ranged from 4.1% to 7.7% with the event rates in asymptomatic patients ranging from 2.3% to 6.7%. In a multivariate analysis (correcting for indication), the use of preoperative antiplatelet agents (odds ratio [OR], 0.70), intraoperative heparin (OR, 0.49), and patch angioplasty (OR, 0.73) was significantly associated with lower combined event rates. There were significant differences among states in the use of preoperative antiplatelet therapy (range, 56%-70%) and patch angioplasty (range, 11%-49%). Combined event rates for repeat procedures (n = 380) and CEA combined with coronary artery bypass grafting (n = 236) were 6.3% and 17.4%, respectively. CONCLUSIONS: The striking variation among states suggests that there is room for improvement in the utilization, care processes, and outcomes of CEA. All surgeons performing CEA should participate in outcome assessment and adopt protocols that include the routine administration of antiplatelet agents preoperatively, the use of heparin intraoperatively, and patch angioplasty of the endarterectomy site. (+info)
B-scan ultrasonographic findings in the stages of idiopathic macular hole.
PURPOSE: To prospectively evaluate the relationship between the posterior hyaloid membrane (PHM) and the retina in eyes with idiopathic macular hole. METHODS: Ninety-four eyes of 94 consecutive patients with macular hole underwent complete ophthalmologic examination, contact lens biomicroscopy, and B-scan ultrasonography and/or vitreoretinal surgery. RESULTS: In 93 of 94 patients (99%), the relationship between the PHM and posterior retina could be visualized during echographic examinations or at surgery. Among these 93 patients, the PHM was detectable biomicroscopically in 36 (39%). Persistent PHM attachment to the foveola with partial separation of the PHM from the perifoveal retina was evident with ultrasonography in 5 of 6 patients (83%) with stage 1 hole and in 12 of 18 patients (67%) with stage 2 hole. When axial views were included, separation of the PHM from the perifoveal retina was evident in 13 of 13 patients (100%) with stage 1 and stage 2 hole. Separation of the PHM from the fovea and perifoveal retina with attachment to the peripapillary retina was evident with ultrasonography in 65 of 65 patients (100%) with stage 3 macular hole and pseudo-operculum and was evident biomicroscopically in 22 of the 65 patients (34%) in this group. CONCLUSIONS: These findings suggest that high-resolution axial and paraxial ultrasonographic examination directly on the surface of the eye is more sensitive in detecting separation of the PHM from the retina than biomicroscopy in idiopathic macular holes. The perifoveal detachment of the PHM may be involved in the pathogenesis of macular holes. (+info)