Biomedical subjects
L W Norton
Publications and source records attributed to L W Norton.
Milk fistula: a complication after core breast biopsy.
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A prospective study of incisional time, blood loss, pain, and healing with carbon dioxide laser, scalpel, and electrosurgery.
Carbon dioxide laser incisions are reported to be less painful, less bloody, and less prone to seroma formation and to heal better than scalpel or electrosurgical incisions. We compared all three modalities in a prospective randomized study of cholecystectomy incisions. Time required for the incision and incisional blood loss was less with electrosurgery than with the carbon dioxide laser or scalpel. Postoperative pain and wound healing, however, were the same for all three techniques. The carbon dioxide laser appears to offer no advantage over conventional means of making a standard incision.
Minimal access surgery for gastroesophageal reflux: laparoscopic placement of the Angelchik prosthesis in pigs.
Conventional surgery for gastroesophageal reflux is effective but requires laparotomy. Minimal access surgery for gastroesophageal reflux could provide a decrease in morbidity. The Angelchik antireflux prosthesis is an alternative to fundoplication for the treatment of this ailment. We evaluated the results of laparoscopic placement of the Angelchik prosthesis in 10 pigs. The duration of the procedure averaged 44 min. The mean lower esophageal sphincter pressure increased from 12.2 +/- 2.8 mmHg at baseline to 45.2 +/- 7.8 (P less than 0.05), 32.1 +/- 3.9 (P less than 0.05), and 25.1 +/- 6.5 mmHg (P greater than 0.05) as measured immediately postoperatively, at 1 week, and at 3 weeks, respectively, following placement of the prosthesis. There was no instance of prosthetic migration or esophageal perforation. One postoperative death due to distention and perforation of the colon occurred. Two animals developed distal esophageal impaction of food. We conclude that the antireflux prosthesis can be safely and effectively placed using laparoscopic methods in a porcine model. Further development of this technique is warranted.
Insulin protects against muscle proteolysis induced by septic plasma.
Sepsis, like trauma, causes proteolysis of skeletal muscle. Insulin normally protects against muscle protein degradation. In earlier work using a rat muscle preparation, insulin inhibition of proteolysis decreased in the presence of plasma from injured patients. The current experiments tested the effect of plasma from septic patients on insulin inhibition in the same model. The mean value of protein degradation among eight septic plasma samples was 49% greater than the mean value among five normal plasma samples in soleus muscle and 45% greater in extensor digitorum longus muscle. In the presence of insulin, 10(3) mU/L, the increases in degradation with septic plasma were 42% in soleus muscle and 48% in extensor digitorum longus muscle. Insulin reduced degradation an average of 6% (soleus) and 10% (extensor digitorum longus) in normal plasma and 10% (soleus) and 8% (extensor digitorum longus) in septic plasma. In contrast to results of other studies, these experiments show that the protective effect of a moderate concentration of insulin in resisting muscle protein degradation is not significantly different in the muscle protein degradation is not significantly different in the presence of septic human plasma compared with normal plasma. This finding supports clinical efforts to decrease proteolysis in septic patients by the administration of insulin.
Resident training.
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Endoscopic cholangiography and stone removal prior to cholecystectomy. A more cost-effective approach than operative duct exploration?
Would economic benefit result from performing endoscopic cholangiography and removal of common bile duct stones prior to cholecystectomy in patients who are suspected preoperatively of having choledocholithiasis? In this study, 173 patients had cholecystectomy and 30 (17%) had common bile duct exploration. Records of these patients were reviewed as were those of 31 patients who had only endoscopic cholangiography and endoscopic stone removal. Cost estimates were based on local charges. Cholecystectomy with common bile duct exploration was $6730 more per patient than cholecystectomy alone. Endoscopic cholangiography and endoscopic stone removal was 87% successful in removing duct stones. Had endoscopic cholangiography and endoscopic stone removal been performed preoperatively in patients undergoing cholecystectomy who had suspected choledocholithiasis, 21 of 30 common bile duct explorations could theoretically have been eliminated. This would have saved $85,526 or $2851 per patient undergoing common bile duct exploration. Our analysis suggests that patients who require cholecystectomy and have suspected choledocholithiasis may be treated more cost-effectively by performing endoscopic cholangiography and endoscopic stone removal immediately prior to cholecystectomy than by cholecystectomy and operative common bile duct exploration.
Effect of cancer plasma on skeletal muscle metabolism.
Circulating factors produced by the macrophages mediate skeletal muscle proteolysis in sepsis and trauma. This study was done to determine whether cytokines affect skeletal muscle metabolism in cancer. Using a method initially developed to measure proteolytic factors in sepsis and trauma, plasma from cachectic cancer patients, noncachectic cancer patients, and normal controls was tested for effects on normal rat skeletal muscle (soleus, extensor digitorum longus). The experimental design allows concomitant measurement of protein synthesis, by [14C]phenylalanine uptake, and protein degradation, by tyrosine release. Plasma from cancer patients caused no acceleration of protein degradation. Noncachectic cancer plasma acted synergistically with insulin to increase protein synthesis (P less than 0.05). These results indicate that a growth factor is present in the plasma of cancer patients who have not become cachexic. To our knowledge, this is the first documentation of a cancer plasma growth factor acting at the organ level to induce synthesis. Our data refute the theory that cancer cachexia is mediated by circulating proteolytic factors. In a separate experiment, purified human recombinant tumor necrosis factor (rTNF) was incubated with normal rat skeletal muscle. No changes were seen in synthesis or degradation rates. Skeletal muscle proteolysis does not appear to be directly induced by rTNF.
A good offense.
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Accuracy and cost of needle localization breast biopsy.
The success and cost of needle localization biopsy (NLB) performed with local anesthesia in an outpatient procedure room (81 biopsies, group 1) or under general anesthesia in an operating room (36 biopsies, group 2) were compared in a longitudinal study. Only 78% of operations in group 1 successfully removed the target breast lesion; definite failure occurred in 17%, and results were indeterminate in 5%. Among lesions sought by group 2 procedures, 92% of lesions were removed successfully, 5% were missed, and 3% were indeterminate. The incidence of carcinoma in breast specimens was 17% in group 1 and 22% in group 2. Wound infection occurred after 6% of group 1 biopsies. The total cost of NLB was $775 in group 1 and $1960 in group 2. The difference in cost represented by the use of general anesthesia was $1260. The added expense of NLB done in an operating room under general anesthesia can be justified by a high rate of success in removing the breast lesion, by patient comfort, and by technical ease.
Needle localization breast biopsy: accuracy versus cost.
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Does drainage of intraabdominal pus reverse multiple organ failure?
Intraabdominal abscess induced multiple organ failure in 21 patients. Sepsis was most often due to perforation of the colon and was located with almost equal frequency in the upper and lower abdomen. Four patients died after single laparotomy for drainage. Seventeen were drained operatively more than once (average 3.4 operations) at mean intervals of 10 days. Sixteen of the 21 patients (76 percent) died with multiple organ failure despite drainage. Organ function improved temporarily in only one patient. Autopsy showed that pus had persisted or recurred in three patients. No significant predictors of survival were identified, although the advantage appears to lie with the younger patient in whom multiple organ failure develops relatively late after sepsis (mean 13 days) and who needs ventilatory assistance for less than 1 week. The location, size, and bacteriologic characteristics of abscesses do not appear to influence outcome. This study shows that early and repeated drainage of intraabdominal pus will not reverse multiple organ failure in the majority of patients.
Vaginal injuries in patients with pelvic fractures.
Of 114 females with pelvic fracture encountered over the past 10 years, four (3.5%) had vaginal laceration. Detection of open fracture was immediate in three; two were repaired and recovered uneventfully. The third was recognized to have a laceration that was repaired but she died of other complications after 2 days. Diagnosis of laceration was delayed 72 hours in the fourth patient who developed extensive pelvic abscess requiring multiple drainage procedures. Our experience confirms the importance of early detection and repair of vaginal laceration in females with pelvic fracture to prevent pelvic abscess.
Accuracy of aspiration cytology in detecting breast cancer.
To evaluate the role of needle placement in determining accuracy and to establish criteria for clinical decision making, we used aspiration cytology to diagnose 49 palpable breast masses in patients undergoing excisional biopsy. Closed cytology, obtained by percutaneous aspiration, and open cytology, obtained by aspiration of the excised mass, were compared with histology. Nineteen (39%) of the breast masses were carcinoma. Unsatisfactory cytologic findings were frequent after both closed (37%) and open (24%) aspiration. Most of these aspirates were from mammary dysplasia, suggesting that acellularity rather than needle placement was responsible. Closed aspiration was falsely negative in one patient and falsely suggestive of cancer in five. If atypical, suspicious or malignant cytologic findings were considered to be carcinoma; closed cytology had high sensitivity (94%), low specificity (64%), and a false positive fraction of 36%. The positive predictive value was 76% and the negative predictive value 90%. Accuracy was 81%. If only suspicious or malignant results were considered positive, specificity and positive predictive value increased at the expense of sensitivity and negative predictive value but accuracy did not change. Even with optimal needle placement (open aspiration), accuracy of aspiration cytology was less than 90%.
Paralysis and aortic thrombosis following blunt abdominal trauma.
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A lump in the breast: assessment and options for local treatment.
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Utility of thyroid aspiration biopsy.
The utility of fine-needle aspiration biopsy to detect carcinoma in thyroid nodules was evaluated by a decision-analysis approach in 102 patients. The procedure caused no morbidity. Cytologic diagnoses were categorized as unsatisfactory (4), no abnormality detected (61), atypical (13), suspicious for malignancy (14), malignancy (2), and inflammation (8). The duration of follow-up averaged 13 months. Of 21 thyroidectomy patients, 10 (48%) had carcinoma. Half of the ten patients operated upon for suspicious cytologic findings were found to have malignancy. Assuming criterion I, that atypical, suspicious, or malignancy results indicated cancer, sensitivity was 90%, specificity 77%, false positive fraction 23%, positive predictive value 31%, negative predictive value 99%, and accuracy 79%. Assuming criterion II, that only suspicious or malignancy cytologic findings represented carcinoma, sensitivity was 70%, specificity 90%, false positive fraction 10%, positive predictive value 44%, negative predictive value 96%, and accuracy 88%. We conclude that sensitivity and specificity of fine-needle aspiration biopsy vary depending upon the use of criterion I or II. Accuracy is highest if atypical results are not considered to represent carcinoma. Positive predictive values remain low and negative predictive values are high in either case. The utility of fine-needle aspiration biopsy when interpreted in relation to clinical criteria is supported by these results.