Elderly patients in surgical workloads: a population-based analysis

Elderly (80+ year old) individuals are the fastest-growing segment of the U.S. population. The objective of this study was to use population-based data to examine trends in the number of elderly undergoing major general, vascular, and cardiothoracic surgical procedures. California inpatient data from 1990-2000 was used to identify patients undergoing six procedures: abdominal aortic aneurysm repair (AAA), coronary artery bypass graft (CABG), carotid endarterectomy (CEA), colon resections, lung resections, and pancreatic resections. Despite comprising only 2.7 per cent of the California population, elderly patients were a significant percentage (6-22%) of the caseloads for the six procedures examined. For all six procedures, the percentage of patients that were elderly increased during the study period. The age-specific incidence rates for elderly individuals increased significantly for three of these procedures (CABG, CEA, lung resection), remained unchanged for two (AAA, pancreas resection), and decreased for one (colon resection). Elderly patients are a large and growing part of surgical caseloads. In the near future, the number of elderly individuals in the California state and the U.S. populations will increase dramatically (41% and 35% between 2000 and 2020). To provide the best quality of care, surgeons should embrace research, training, and educational opportunities regarding the treatment of elderly patients.     

Thrombolytic therapy for delayed, in-hospital stroke after cardiac surgery

Five patients who had delayed stroke after cardiac surgery underwent intraarterial administration of a fibrinolytic agent for thromboembolism (n = 4) or thrombosis (n = 1) of the cerebral artery. Complete recanalization of the occluded artery was obtained in 3 patients and partial recanalization in 2. Additional angioplasty for basilar artery stenosis was performed in 1 patient. No patients exhibited rebleeding into the pericardial space or wound bleeding. All patients survived with moderate or full functional recovery. Immediate cerebral angiography and local thrombolysis may improve functional outcome and survival in patients with postcardiotomy cerebral thromboembolism.     

Improved survival for adenocarcinoma of the ampulla of Vater: fifty-five consecutive resections

HYPOTHESIS: After resection of an adenocarcinoma of the ampulla of Vater, certain clinical and pathologic characteristics influence long-term survival. DESIGN: Retrospective case series. SETTING: Major academic medical and pancreatic surgical center. PATIENTS: Fifty-five consecutive patients who underwent Whipple resection for ampullary adenocarcinoma from 1988 through 2001. INTERVENTIONS: Pylorus-preserving Whipple resection in 32 patients and standard Whipple resection in 23 patients. MAIN OUTCOME MEASURES: Postoperative survival. A multivariate Cox proportional hazards model was used to determine the effects of various factors on long-term survival after resection. RESULTS: There were no operative deaths, and all patients left the hospital. After a mean follow-up of 46.9 months, the overall 5-year Kaplan-Meier survival estimate was 67.7%. The median survival of the entire group has not yet been reached. Five-year postoperative survival estimates for node-negative (n = 32) and node-positive patients (n = 23) were 76.5% and 53.4%, respectively (P =.26). Patients whose tumors demonstrated perineural invasion (n = 12) had a 5-year survival estimate of 29.2% vs 78.8% for those whose did not (P<.001). On multivariate analysis, the absence of perineural invasion (P<.001) was an independent predictor of significantly improved postoperative survival. CONCLUSIONS: Compared with previous reports from our own and other centers, this series demonstrates improved postoperative survival by 10% to 20% in patients undergoing Whipple resection for adenocarcinoma of the ampulla of Vater. The reasons for this improved outcome are unclear, and the effect of adjuvant treatment cannot be determined from this analysis. The major factor associated with prolonged survival was the absence of perineural invasion in the resected tumor specimen.     

Evaluation of a novel sutureless anastomotic connector: from endothelial function to mid-term clinical and angiographic follow-up

OBJECTIVES: We evaluated the effect of the St Jude Medical sutureless anastomotic connector on endothelium-dependent and -independent saphenous vein graft relaxation, as well as on clinical outcomes and graft patency in patients. METHODS: Human saphenous vein grafts were assigned to control or connector groups (loaded for 1 or 5 minutes; n = 18). Isometric dose-response curves to endothelium-dependent and -independent (sodium nitroprusside) vasodilators were constructed in saphenous vein grafts precontracted with phenylephrine. Thrombin-mediated vasorelaxation, an early determinant of saphenous vein graft failure, was also evaluated. Percent maximum relaxation was compared between groups. Patients in whom the St Jude Medical connector was employed underwent clinical follow-up, stress tests, and angiography 6 to 12 months postoperatively. RESULTS: A23187-induced endothelium-mediated relaxation, sodium nitroprusside-induced endothelium-independent relaxation, and thrombin-mediated vasorelaxation did not differ between control and connector saphenous vein grafts at either time point studied. Twenty-seven patients received St Jude Medical connectors. There was no hospital mortality; patients were followed for 679 +/- 241 days. There was 1 late death; the connector saphenous vein graft was patent at postmortem. All connector saphenous vein grafts were patent at follow-up angiography. Four grafts had stenoses (30%-60%), without symptoms or requirement for intervention. All hand-sewn saphenous vein grafts were also patent. CONCLUSIONS: The St Jude Medical connector does not impair endothelium-dependent vasorelaxation. In patients, patency of the connector saphenous vein grafts 6 to 12 months postoperatively was 100% but 22% of grafts had non-flow-limiting stenoses at or near the connector. Further long-term studies are required to confirm the safety of the St Jude Medical connector with regards to endothelial function and restenosis.     

Effects of high dose oral creatine supplementation on anaerobic capacity of elite wrestlers

AIM: The purpose of this study was to investigate the effect of high dose oral creatine supplementation on anaerobic capacity of elite wrestlers. METHODS: Experimental design: comparative randomized design. Setting: Wingate anaerobic tests of the participants were taken at the Human Performance Laboratory of the Department of Physical Education and Sports in The Middle East Technical University, Ankara, Turkey. Participant: 20 active international level wrestlers participated (22 to 27 years old). Interventions: the daily dosage of creatine or placebo was divided into 4 equal amounts (5 gx4 = 20 g). Every 5 g of supplement was dissolved in 250 ml water and it was given to participants 1 hour before breakfast, lunch, dinner, and workout session. Measures: subjects underwent a 30-s Wingate Anaerobic tests until exhaustion in pre- and post-tests. After the pretest measurements were completed, participants were classified as creatine (Cr., n=10) and placebo (Pl., n=10) groups with regard to their average anaerobic power scores obtained during the test. RESULTS: Results of paired "t"-test revealed that there was no significant change in placebo group between pre- and post-test in average and peak anaerobic power. However, average and peak power mean scores obtained from post-test (8.123+/-0.448 W/kg and 10.523 +/-1.004 W/kg) were significantly (p<0.01) higher than pretest (7.233+/-0.483 W/kg and 8.992+/- 0.665 W/kg) for creatine group. Results of the independent "t"-test also indicated that the mean gained scores of creatine group in average and peak power were significantly higher than placebo group (p<0.01). CONCLUSION: This study demonstrates that short-term high dose oral creatine supplementation has an ergogenic effect on anaerobic capacity of elite wrestlers.     

Polyethylene wear in total hip prostheses: the influence of direction of linear wear on volumetric wear determined from radiographic data

Purpose To develop a new mathematical model for calculating the volumetric wear of polyethylene cups from known values of the radius of the prosthesis head, the extent of linear wear and the direction of linear wear determined from standard antero-posterior radiographs.Method A new mathematical model was developed. The results of this new mathematical model were compared with the results obtained using the standard, frequently used mathematical model, which takes into consideration only the radius of the prosthesis head and the extent of linear wear of the polyethylene cups. The results of both mathematical models were further compared with the results obtained by direct measurement of volumetric wear using the fluid displacement method.Results Comparison of the mathematical models shows that the average volumetric wear calculated using the new mathematical model is 8.5% smaller than the average volumetric wear determined by the fluid displacement method, while the average volumetric wear calculated by standard mathematical model is 17.5% higher. The results of the new mathematical model are, thus, notably less biased than those of the standard one.Conclusion In calculating the volumetric wear from antero-posterior radiographs, not only the radius of the prosthesis head and the extent of the linear wear but also the direction of the latter has to be considered.     

Liquid-Crystal Display Monitors and Cathode-Ray Tube Monitors: A Comparison of Observer Performance in the Detection of Small Solitary Pulmonary Nodules

Objective

To compare observer performance using liquid-crystal display (LCD) and cathode-ray tube (CRT) monitors in the interpretation of soft-copy chest radiographs for the detection of small solitary pulmonary nodules.

Materials and Methods

By reviewing our Medical Center''s radiologic information system, the eight radiologists participating in this study (three board-certified and five resident) retrospectively collected 40 chest radiographs showing a solitary noncalcified pulmonary nodule approximately 1 cm in diameter, and 40 normal chest radiographs. All were obtained using a storage-phosphor system, and CT scans of the same patients served as the gold standard for the presence of a pulmonary nodule. Digital images were displayed on both high-resolution LCD and CRT monitors. The readers were requested to rank each image using a five-point scale (1 = definitely negative, 3 = equivocal or indeterminate, 5 = definitely positive), and the data were interpreted using receiver operating characteristic (ROC) analysis.

Results

The mean area under the ROC curve was 0.8901±0.0259 for the LCD session, and 0.8716±0.0266 for the CRT session (p > 0.05). The reading time for the LCD session was not significantly different from that for the CRT session (37.12 and 41.46 minutes, respectively; p = 0.889).

Conclusion

For detecting small solitary pulmonary nodules, an LCD monitor and a CRT monitor are comparable.     

Stereotactic Core-Needle Biopsy of Non-Mass Calcifications: Outcome and Accuracy at Long-Term Follow-Up

Objective

To determine, by means of long-term follow-up evaluation, the outcome and accuracy of stereotactic core-needle biopsy (SCNB) of non-mass calcifications observed at mammography, and to analyze the factors contributing to false-negative findings.

Materials and Methods

Using a 14-gauge needle, SCNB was performed in cases involving 271 non-mass calcified lesions observed at mammography in 267 patients aged 23-72 (mean, 47) years. We compared the SCNB results with those of long-term follow-up which included surgery, mammography performed for at least six months, and reference to Korean Cancer Registry listings. We investigated the retrieval rate for calcifications observed at specimen mammography and histologic evaluation, and determined the incidence rate of cancer, sensitivity, and the underestimation rate for SCNB. False-negative cases were evaluated in terms of their mammographic findings, the effect of the operators'' experience, and the retrieval rate for calcifications.

Results

For specimen mammography and histologic evaluation of SCNB, the retrieval rate for calcifications was, respectively, 84% and 77%. At SCNB, 54 of 271 lesions (19.9%) were malignant [carcinoma in situ, 45/54 (83%)], 16 were borderline, and 201 were benign. SCNB showed that the incidence of cancer was 5.0% (6/120) in the benign mammographic category and 31.8% (48/151) in the malignant category. The findings revealed by immediate surgery and by long-term follow-up showed, respectively, that the sensitivity of SCNB was 90% and 82%. For borderline lesions, the underestimation rate was 10%. For false-negative cases, which were more frequent among the first ten cases we studied (p = 0.01), the most frequent mammographic finding was clustered amorphous calcifications. For true-negative and false-negative cases, the retrieval rate for calcifications was similar at specimen mammography (83% and 67%, respectively; p = 0.14) and histologic evaluation (79% and 75%, respectively; p = 0.47).

Conclusion

In this study group, most diagnosed cancers were in-situ lesions, and long-term follow-up showed that the sensitivity of SCNB was 82%. False-negative findings were frequent during the operators'' learning period.     

Hyponatremic encephalopathy--some experimental and clinical findings

Hyponatremia is a common electrolyte disturbance occurring in a broad spectrum of patients, from asymptomatic to critically ill. The disease is defined as a decrease in serum sodium concentration to a level below 136 mmol per liter. The brain damage from hyponatremia can be associated with either hyponatremic encephalopathy or improper therapy of symptomatic hyponatremia both in patients and in experimental models of hyponatremia in rats. This review covers the clinical symptoms of hyponatremia as well as the consequences of its correction. It also summarises the effects of experimental hyponatremia associated with vasopressin on some aspects of cerebral blood flow regulation and the morphology of cerebral tissue.