Risk analysis of blood transfusion requirements in emergency and elective spinal surgery.

Spinal surgery has long been considered to have an elevated risk of perioperative blood loss with significant associated blood transfusion requirements. However, a great variability exists in the blood loss and transfusion requirements of differing patients and differing procedures in the area of spinal surgery. We performed a retrospective study of all patients undergoing spinal surgery who required a transfusion≥1 U of red blood cells (RBC) at the National Spinal Injuries Unit (NSIU) at the Mater Misericordiae University Hospital over a 10-year period. The purpose of this study was to identify risk factors associated with significant perioperative transfusion allowing the early recognition of patients at greatest risk, and to improve existing transfusion practices allowing safer, more appropriate blood product allocation. 1,596 surgical procedures were performed at the NSIU over a 10-year period. 25.9% (414/1,596) of these cases required a blood transfusion (n=414). Surgical groups with a significant risk of requiring a transfusion>2 U RBC included deformity surgery (RR=3.351, 95% CI 1.123-10.006, p=0.03), tumor surgery (RR=3.298, 95% CI 1.078-10.089, p=0.036), and trauma surgery (RR=2.444, 95% CI 1.183-5.050, p=0.036). Multivariable logistic regression analysis identified multilevel surgery (>3 levels) as a significant risk of requiring a transfusion>2 U RBC (RR=4.682, 95% CI 2.654-8.261, p<0.0001). Several risk factors in the spinal surgery patient were identified as corresponding to significant transfusion requirements. A greater awareness of the risk factors associated with transfusion is required in order to optimize patient management.

Plaque disruption and thrombus in Ambrose's angiographic coronary lesion types.

Lesion eccentricity with irregularities on coronary angiography is associated with ruptured plaques and thrombus based on postmortem and clinical angiographic studies. However, the predictive value of such angiographic markers of plaque disruption and thrombus remains to be determined in vivo. The purpose of this study was to establish whether Ambrose's angiographic coronary lesion types and other angiographic criteria predict the presence of disrupted plaques and thrombus using intracoronary angioscopy. Angioscopy was performed before angioplasty in 60 patients with various coronary syndromes and culprit lesions that were not totally occlusive. Lesions were classified angiographically according to Ambrose's criteria as concentric, type I and II eccentric, and multiple irregularities, or as complex or noncomplex, and then compared with the corresponding angioscopic findings. Disruption and/or thrombus were seen in 17 of 19 type II eccentric lesions and 21 of 23 angiographically complex lesions and had the highest positive predictive value to detect complicated atherosclerotic plaques (type II eccentric lesions: positive predictive value 89%, 95% confidence intervals 67% to 99%; complex lesions: 91%, 95% confidence intervals 72% to 99%). We conclude that Ambrose's type II eccentric stenoses and angiographically complex lesions are strongly associated with disrupted plaques and/or thrombus as assessed by angioscopy in patients and represent unstable plaque substrates.

Powered partial adenoidectomy.

OBJECTIVE: To confirm our clinical impression that the powered microdebrider is superior to curettes for performing partial adenoidectomy (removal of the superior one half to three fourths of the adenoid pad). DESIGN: Observational study of 100 children undergoing partial adenoidectomy with the powered microdebrider compared with 40 children undergoing conventional partial adenoidectomy with curettes. SETTING: Private and public tertiary care centers. PATIENTS: All patients younger than 20 years undergoing partial adenoidectomy at the respective institutions during the study period. INTERVENTIONS: Partial adenoidectomy as indicated for chronic otitis media, airway obstruction, or chronic or recurrent tonsillitis with either the powered microdebrider or curettes. MAIN OUTCOMES MEASURES: Operative time (with specific quantification of the time required for tissue removal and hemostasis), blood loss, complications, and subjective ease of use. RESULTS: Operative time was 59% shorter for the microdebrider group (mean, 3 minutes 22 seconds; range, 1 minute 6 seconds to 12 minutes 45 seconds) than for the conventional group (mean, 8 minutes 8 seconds; range, 1 minute 2 seconds to 22 minutes 0 seconds) (P<.001). Blood loss was comparable for both groups (powered group: mean, 2.0 mL/kg; range, 0.4 to 9.4 mL/kg; conventional group: mean, 2.0 mL/kg; range, 0.3 to 6.7 mL/kg; P=.34). There were no intraoperative or postoperative complications in either group. Surgeon satisfaction with the microdebrider was high. CONCLUSIONS: The powered microdebrider for partial adenoidectomy is quicker and is not associated with blood loss or complications above that of conventional partial adenoidectomy. The degree of control afforded by the microdebrider technique is of utmost value in preventing complications such as velopharyngeal insufficiency, and this is now our procedure of choice.

Probing the influence of steric bulk on anion binding by triarylboranes: comparative studies of FcB(o-Tol)2, FcB(o-Xyl)2 and FcBMes2.

Steric crowding brought about on pyramidalization at boron has been predicted computationally to be of central importance to the strength and selectivity of anion binding by triarylboranes. The role of steric factors in systems containing a ferrocenyl reporter unit has been systematically probed in the current study by comparison of the F(-)/CN(-) binding properties of FcB(o-Tol)(2) (1, o-Tol = C(6)H(4)Me-2), FcB(o-Xyl)(2) (2, o-Xyl = C(6)H(3)Me(2)-2,6) and FcBMes(2) (3, Mes = C(6)H(2)Me(3)-2,4,6)), both in solution and in the solid state. Somewhat surprisingly, the inclusion of an extra ortho-methyl aryl substituent (e.g. for 2/3vs.1) is found to have a relatively small effect on the binding affinities of these boranes (e.g. log(10)K(CN) = 5.94(0.02), 4.73(0.01), 5.56(0.02), for 1, 2 and 3 respectively). Consistent with this observation, the degree of pyramidalization at boron determined for the cyanide adducts [1·CN](-), [2·CN](-) and [3·CN](-) in the solid state is also found to be essentially invariant (∠C(aryl)-B-C(aryl) = 338, 337, 337°, respectively), as are the B-CN and mean B-C(aryl) distances. In the solid state at least, it is apparent that the adverse steric effects potentially brought about by increasing ortho substitution are mitigated by a greater degree of synchronous rotation of the aryl substituents about the B-C(aryl) bonds. Thus a mean inter-plane angle of 71° is observed for [1·CN](-) while the corresponding values for [2·CN](-) and [3·CN](-) are 78° and 79°.

The management and functional outcome of isolated burst fractures of the fifth lumbar vertebra.

STUDY DESIGN: We retrospectively reviewed 14 cases of isolated burst fractures of the fifth lumbar vertebra (L5) presenting over a 10-year period to the National Spinal Injuries Unit (NSIU) of the Republic of Ireland. OBJECTIVES: The objective was to evaluate treatment outcomes in patients suffering isolated burst fractures of L5 without neurologic compromise managed operatively and nonoperatively. SUMMARY OF BACKGROUND DATA: Burst fractures of L5 represent a very small proportion of all spinal injuries. The unique anatomic and biomechanical characteristics of this region protect it from traumatic injury. METHODS: Fourteen patients (n = 14) were managed for isolated burst fractures of L5 at the NSIU over a 10-year period. The Hospital Inpatient Enquiry System and the NSIU Database identified our study cohort. A retrospective analysis of the medical records, radiographs, and CT scans of all patients identified was performed. Loss of anterior vertebral height, degree of kyphotic deformity, and percentage retropulsion were recorded at several phases of treatment. Follow-up clinical evaluation was performed with respect to pain status, work and recreational restrictions, along with overall patient satisfaction. RESULTS: Of the study cohort (n = 14), 10 patients were managed nonoperatively and 4 patients operatively. The nonoperative group showed a superior radiographic outcome at follow-up, with the nonoperative group showing a mean loss of anterior vertebral height of 15.7% and a mean kyphotic deformity of 10.4 degrees. The operative group, in contrast, had a mean loss of anterior vertebral height of 19% and mean kyphotic deformity of 11 degrees at follow-up. The nonoperative group additionally exhibited superior results at clinical follow-up regarding pain status, work and recreational restrictions, and overall satisfaction. CONCLUSIONS: In the largest series to date of isolated burst fractures of L5, we strongly advocate the nonoperative management of these injuries, particularly in cases of moderate bony deformity, minimal canal compromise, and no neurologic deficit.