Biomedical subjects
Publications and source records attributed to V Velanovich.
Subungual pigmented lesions may be difficult to diagnose. A wide range of diseases present as pigmented lesions. The most concerning is subungual melanoma. A case is presented of a bone spur causing a subungual lesion mimicking melanoma. If subungual lesions do not show signs of resolution, timely biopsy is indicated.
Ankyloglossia is a congenital anomaly in which the frenulum is attached to the tip of the tongue to varying degrees. Children affected by this condition may be unhindered or they may have a variety of problems to include dysfunctional breast-feeding and speech mechanics. This article describes the indications for and surgical technique of the transverse-vertical frenuloplasty for the treatment of ankyloglossia.
The purpose of this study was to evaluate the value of preoperative electrocardiography in predicting postoperative cardiac complications. Four hundred eighty-one patients having elective surgery were eligible. The patients' ages and specific ECG findings were recorded preoperatively. The patients had prospective follow-up from admission to discharge for the development of postoperative cardiac complications. The data were analyzed using stepwise logistic regression. Postoperative ischemic events were predicted by ECG findings of ST segment abnormalities and ECG evidence of previous myocardial infarction. Age, P wave abnormalities, and preoperative dysrhythmias were independent predictors of postoperative dysrhythmic events. These specific ECG findings may identify patients at risk of postoperative ischemia or dysrhythmia. These patients may benefit from aggressive preoperative cardiac evaluation or close postoperative cardiac monitoring.
BACKGROUND: The purpose of this study was to determine the most efficient preoperative laboratory screening for elective surgery. METHODS: Five hundred twenty patients undergoing elective operations on the general, vascular, thoracic, and head and neck surgical services were eligible for the study. The patient characteristics evaluated were age, gender, race, American Society of Anesthesiologists physical status classification, ponderal index, presence of concomitant respiratory disease, coronary artery disease, other heart disease, kidney disease, endocrine disease, malignancy, peripheral vascular disease, hypertension, diabetes mellitus, and neuropsychiatric disease. Preoperative laboratory screening included electrolytes, blood urea nitrogen, creatinine, and glucose levels, hemogram, nutritional studies (total protein and albumin levels and total lymphocyte count), coagulation studies (prothrombin time, partial thromboplastin time, and platelet count), urinalysis, electrocardiogram, and chest radiograph. Univariate analysis was done by Pearson's Chi square with Yate's correction. Significant p values were adjusted with Bonferroni's correction. Multivariate analysis was done with stepwise logistic regression. RESULTS: Univariate analysis showed age, gender, and the specific concomitant illness were associated with specific abnormal preoperative laboratory test results. Similarly, multivariate analysis showed specific predictors based on these risk factors. CONCLUSIONS: Routine preoperative laboratory testing is neither useful nor cost-effective. Appropriate preoperative laboratory testing can be based on age, gender, concomitant medical diseases, and type of operation to be performed.
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As do all forms of science, medical theories have a factual as well as a logical basis. New information is presented in medical research articles. These papers have three separate arguments: the argument of the hypothesis, the argument of the experimental protocol, and the argument of the hypothesis's judgement. These arguments may be examples of the hypothetico-deductive or confirmational model of scientific interference. The logical form of these arguments are informal and inductive rather than formal and deductive. Understanding the nature of the logic of the medical research article may help avoid erroneous conclusions.
The management of blunt splenic trauma in children has remained controversial, with different physicians advocating observation, splenorrhaphy, and splenectomy. Proponents for each position have debated the relative importance of rebleeding (delayed splenic rupture), posttransfusion hepatitis with its sequelae, and overwhelming postsplenectomy sepsis. In an attempt to guide the clinician, a decision analysis was performed. Variables evaluated included the incidence of transfusion, postsplenectomy sepsis, posttransfusion hepatitis, chronic active hepatitis, cirrhosis, and rebleeding. The quality-adjusted life expectancies (QALEs) when the average incidence of the variables were used in the decision analysis were 62.69 years for observation, 62.32 years for splenorrhaphy, and 61.14 years for splenectomy. Sensitivity analysis showed that there was very little difference between observation and splenorrhaphy when the transfusion rate and hepatitis rate were varied. But these treatment options produced longer QALEs than splenectomy. Therefore, in appropriately selected patients, observation is a safe and effective therapeutic option. If an operation is necessary, every effort should be made to preserve the spleen. Splenectomy may still be required in those cases of complete devascularization, persistent hemorrhage, or other associated significant injuries.
Routine preoperative laboratory testing has become dogma to many. Often, surgeons, anesthesiologists, hospital administrators, and even patients expect that there will be some "labs" on the chart prior to any operative procedure. Many have questioned the usefulness and cost-effectiveness of such a policy. There is little evidence to support the need for routine preoperative testing and much evidence against it. Preoperative testing should be based on appropriate indications. This makes the assessment of the preoperative laboratory evaluation difficult for a medical quality assurance program. The question that arises is, how much routine preoperative laboratory testing is enough? The answer to this question depends on (a) the purpose of this testing and (b) the limitations and potential misinterpretations of laboratory testing. This article will discuss the reasons for the potential misinterpretation of laboratory tests and then the data supporting selective preoperative laboratory testing.
The purpose of this study was to identify factors from simple past medical history which could alert surgeons to patients at increased risk of postoperative complications. Five hundred and fourteen patients undergoing elective surgery were studied prospectively. Factors evaluated included the patients' age, gender, race and the presence in the past medical history of coronary artery disease, congestive heart failure, cardiac dysrhythmias, respiratory disease, endocrine disease, peripheral atherosclerosis, renal disease, neuropsychiatric disease, hypertension, diabetes mellitus, prior major surgery and prior or active malignancy. All complications were recorded. The data were analysed by univariate and multivariate statistical methods. Gender, race and age were not associated with any complications. Coronary artery disease, respiratory disease, atherosclerotic peripheral vascular disease, neuropsychiatric disease, malignancy, the absence of prior major surgery, hypertension and diabetes mellitus were associated with specific postoperative complications by univariate analysis. Malignancy, diabetes mellitus, peripheral atherosclerosis, coronary artery disease, neuropsychiatric disease, renal disease and respiratory disease were independent predictors of complications as determined by multivariate analysis. Of interest is the phenomenon that the risk of postoperative complications when a combination of risk factors was present was greater than what would be predicted by the cumulative risk of these factors. This study helps identify those patients which by simple history may be at increased risk of postoperative complications and may require aggressive preoperative evaluation.
The role of fine needle aspiration (FNA) for clinical decision-making in patients with nodules of the breast remains in evolution. We retrospectively studied FNA outcomes in 183 patients, stratified by decades of age, to determine the reliability of FNA cytologic examination. Using Bayesian analysis, the predictive value of a positive FNA for women more than 60 years of age is 98 to 99 percent. In women 41 to 60 years of age, those with a first-degree relative with carcinoma of the breast and those with a prior biopsy with increased risk have an 88 to 95 percent likelihood of carcinoma. In women younger than 41 years of age, this likelihood decreases to 65 percent. Additionally, the probability of a lump being carcinoma, given the FNA was negative, ranges from 3 to 80 percent. Therefore, biopsy of a dominant nodule should not be deferred based only on a negative FNA. We can conclude that women 61 years of age or older could be counseled for definitive care at the first operation. Women 41 to 60 years of age, those with a positive family history or those with a past biopsy with increased risk, could be counseled for definitive therapy, but have the diagnosis confirmed with frozen section. Women less than 40 years of age without other risk factors receive no diagnostic benefit from FNA and should only be evaluated with open biopsy.
The balloon cholangiocater has become popular for laparoscopic intraoperative cholangiography. Two pitfalls of this instrument include apparent common bile duct injury and pseudo-Mirizzi anatomy. These pitfalls are illustrated, and their correction is discussed.
Although complications of Meckel's diverticula are relatively common, there has not been a reported case, to our knowledge, of foreign bodies impacted within a Meckel's diverticulum. We report herein a case of a 2-year-old child who had two pennies trapped in a Meckel's diverticulum. This case demonstrates that foreign objects in the right lower quadrant that do not progress may be impacted in a Meckel's diverticulum.
Pseudomembranous colitis and toxic megacolon are rare complications of antineoplastic chemotherapy. Twelve cases of pseudomembranous colitis and four cases of toxic megacolon, both occurring as complications of chemotherapy, have been reported in the medical literature. These diseases occurred as separate and distinct entities. Fulminating pseudomembranous colitis leading to toxic megacolon in the setting of chemotherapy has not been previously reported. We report such a case, emphasizing its atypical presentation and rapid, fulminant course.
A 38-year old female with a history of biliopancreatic diversion for morbid obesity developed a perforation at the distal Roux-en-Y anastomosis 13 months after the original surgery. The etiology of this complication was not determined. Perforation of a Roux-en-Y anastomosis occurring this late in the postoperative period has not been described previously.
Parapneumonic effusions are relatively common sequelae of pneumonias. Occasionally, parapneumonic effusions will lead to empyemas. If these fluid collections are not aggressively drained in a timely manner, they will become loculated, placing the patient at risk for septic complications. Two cases of parapneumonic empyemas with delayed drainage eventually requiring thoracotomy and decortication are presented. These cases illustrate the need for early, complete drainage of parapneumonic empyemas to avoid septic complications and unnecessary surgery.
Debate continues as to what should be the appropriate "negative" appendectomy rate for patients suspected of having acute appendicitis. The controversy centers around balancing the complications of appendectomy for a normal appendix with those for a perforated appendix. By using a decision analysis approach to the probable outcomes of appendectomy for a normal appendix, acute appendicitis, and perforated appendicitis, this study provides one answer to this question. These outcomes are based on a review of the results of over 10,000 appendectomies. There is an inverse relationship between the normal appendectomy rate and perforated appendicitis rate. The overall complication rate in patients suspected of having appendicitis improved when the rate of perforated appendicitis was lowered, even if this meant raising the negative appendectomy rate. The perforation rate seemed to level off at approximately 10 per cent. The quality of surgical care delivered to a given population should not be judged solely on the normal appendectomy rate, but this rate should be interpreted in the light of the perforated appendicitis rate. Quality assurance assessments should focus first on perforated appendicitis and only later on normal appendectomy.
The therapeutic approach to a patient with concomitant abdominal aortic aneurysm and colorectal carcinoma is not clear. Decision analysis helps clarify decision options and quantify therapeutic outcomes. Variables used in decision analysis include life expectancy after resection for colorectal cancer and abdominal aortic aneurysm, rupture rate of abdominal aortic aneurysm, complications of colorectal The results support the concept that the symptomatic lesion should be treated first. When both lesions are asymptomatic and the aneurysm is 4-5 cm in diameter, it should be resected first, if the colorectal cancer has a less than 5% chance of obstruction or perforation, as is found in noncircumferential lesions. When the aneurysm is greater than 5 cm, it should be resected first if the cancer has a less than 22% chance of obstructing or perforating, as with circumferential lesions. Simultaneous resection should be considered for patients with aneurysms greater than 5 cm and cancers with a greater than 75-80% chance of obstruction or perforation, provided the dual procedures can be performed with a less than 10% operative mortality and less than 50% complication rate.
Bayesian analysis is a method by which the reliability of diagnostic tests can be determined. It produces a probability of a patient having the disease given a positive test result (posterior probability). If more than one study of a given test's diagnostic accuracy is done, then how can we determine which of these studies has produced the most reliable posterior probability? Meta-analysis is a method whereby data from different studies can be combined. This paper proposes that meta-analysis more accurately estimates the true Bayesian posterior probability than other methods of data pooling.