Complete replacement of the peroneus longus muscle by a ganglion with compression of the peroneal nerve: a case report.

In a 38-year-old woman, the entire muscle belly of the peroneus longus was replaced by a ganglion. Signs of peroneal nerve dysfunction resulted from direct pressure of the ganglion. Excision of the ganglion required a tenodesis of the peroneus longus tendon to provide a normal gait pattern which was maintained during a 17 month follow-up period. This entity needs careful, prompt evaluation to avoid neurological damage and to distinguish it from compartment syndrome.     

Colon perforation following percutaneous nephrostomy and renal calculus removal

Two patients had colonic perforation as a result of percutaneous nephrostomy placement followed by track dilatation and renal calculus removal. We present the technical aspects of nephrostomy placement and stone removal, as well as the clinical diagnosis and management of these cases. Both patients recovered well with conservative therapy and required no surgical intervention. This report reviews the anatomic considerations for percutaneous nephrostomy in patients undergoing renal stone removal.     

Flow patterns in the aortic root and the aorta studied with time-resolved, 3-dimensional, phase-contrast magnetic resonance imaging: implications for aortic valve-sparing surgery

OBJECTIVE: Sparing the aortic valve has become a surgical option for patients who require repair of aortic root ectasia and have normal valve leaflets. Surgical approaches to valve sparing differ with regard to preservation of the native sinuses of Valsalva. The role of the sinuses and the importance of maintaining them remain controversial. METHODS: By using a time-resolved, 3-dimensional, phase-contrast magnetic resonance imaging technique, aortic root and aortic blood velocity data were acquired from 2 patients with Marfan syndrome 6 months after aortic valve-sparing surgery with straight Dacron grafts and contrasted with data from 6 normal volunteers. RESULTS: In normal aortas vortical blood flow became apparent in the individual sinuses after peak systole. The vortices filled the available space behind the valve leaflets and persisted until diastole, expanding and moving inward during aortic valve closure. In contrast, no vortices were observed in the postoperative patients with Marfan syndrome with negligible sinuses. CONCLUSIONS: Changes in supravalvular flow accompany loss of sinus architecture. Whether the presence, size, and velocity of supravalvular vortices affects the function or durability of the preserved aortic valve remains to be studied.     

Hypertension: pathophysiology and treatment

Arterial hypertension is a major cause of morbidity and mortalitybecause of its association with coronary heart disease, cerebrovasculardisease and renal disease. The extent of target organ involvement(i.e. heart, brain and kidneys) determines outcome. North Americanstudies have shown that hypertension is a major contributorto 500 000 strokes (250 000 deaths) and 1 000 000 myocardialinfarctions (500 000 deaths) per annum.     

A framework for assessing risks to children from exposure to environmental agents

In recent years there has been an increasing focus in environmental risk assessment on children as a potentially susceptible population. There also has been growing recognition of the need for a systematic approach for organizing, evaluating, and incorporating the available data on children's susceptibilities in risk assessments. In this article we present a conceptual framework for assessing risks to children from environmental exposures. The proposed framework builds on the problem formulation-->analysis-->risk characterization paradigm, identifying at each phase the questions and issues of particular importance for characterizing risks to the developing organism (from conception through organ maturation). The framework is presented and discussed from the complementary perspectives of toxicokinetics and toxicodynamics.     

Proxy and surrogate consent in geriatric neuropsychiatric research: update and recommendations

OBJECTIVE: The ethics of involving decisionally incapable adults in research will continue to grow in importance as more research is conducted to address the problems of decisionally impaired persons, especially elderly persons. The authors provide an updated discussion, critique, and recommendations regarding the need for clear legal and regulatory policy on this issue. METHOD: The authors summarize and build on discussions of a workshop on proxy and surrogate consent in geriatric neuropsychiatric research sponsored by the Aging Research Consortium of the National Institute of Mental Health. They incorporate the views of various stakeholders present at the workshop as well as review recent federal and state initiatives, recent empirical research and media reports, and various commission reports and relevant regulations. RESULTS: Despite a wave of initiatives in the late 1990s to clarify policy, surrogate consent for research continues to be a murky legal area and incapable subjects in the United States still lack clear regulatory protection. There is evidence that conservative risk management strategies by institutional review boards and their institutions may severely restrict research with decisionally impaired subjects. A passive approach to this problem may no longer be feasible. A recent federal advisory report on human research protections and legislative initiatives in some states could begin to provide a blueprint for future policy making. Interim recommendations for various stakeholders are given. CONCLUSIONS: It is imperative that the scientific community, patients and their advocates, and policy makers at all levels establish a constructive dialogue to clarify ethical and legal standards in the area of proxy and surrogate consent for research.     

Renal artery disease: diagnosis and management

Renal artery stenosis (RAS) is most commonly due to either fibromuscular dysplasia or atherosclerosis. The former predominates in young women while atherosclerosis is usually encountered in individuals over the age of 55. The most common clinical manifestation of fibromuscular dysplasia is hypertension, which can frequently be cured or significantly improved with percutaneous balloon dilation. Atherosclerotic RAS may present with hypertension, renal failure (ischemic nephropathy), recurrent episodes of congestive heart failure and flash pulmonary edema or may be discovered incidentally during an imaging procedure for some other reason. Screening tests for RAS have improved considerably over the last decade. While captopril renography was utilized almost exclusively in the past, duplex ultrasound of the renal arteries or magnetic resonance angiography have replaced other modalities as the screening test of choice in many centers. Rarely does an arteriogram have to be performed for diagnostic purposes only. Management of RAS consists of three possible strategies: medical management, surgical management or percutaneous therapy with balloon angioplasty and stent implantation. The treatment of choice to control hypertension in patients with fibromuscular disease is percutaneous angioplasty. Renal artery stenting has replaced surgical revascularization for most patients with atherosclerotic disease who meet the criteria for intervention.     

Aortic valve replacement with pericardial valves in patients with small aortic roots. Clinical results in a consecutive series of patients receiving 19 and 21 mm prostheses

OBJECTIVE: To determine how second generation pericardial valves perform in patients with small aortic roots. DESIGN: Ninety patients who underwent isolated aortic valve replacement (AVR) with 19 or 21 mm Mitroflow or Carpentier-Edwards (Perimount) valves between 1989 and 1996 were studied. Mean age was 78 years. Concomitant coronary bypass surgery was performed in 41%. RESULTS: Thirty-day mortality was 5.6%. Ninety-seven percent had acceptable transprosthetic mean pressure gradients (25 mmHg or less) 1 week after surgery. Follow-up was 100% complete and 76% of the patients were alive after a mean of 5 years. There was no structural valve failure or valve thrombosis. One patient required reoperation for perivalvular leak. Four patients had transient ischemic attacks and seven had strokes. These figures are, however, within the expected range for the age. CONCLUSION: Second generation pericardial valves perform well in elderly patients with small aortic roots. Postoperative hemodynamics are acceptable, valve durability of up to 8 years adequate, and the clinical results good, considering the age of the patients.     

Inherited disorders of 3-methylcrotonyl CoA carboxylation

The clinical course of 4 patients who had reduced activities of 3-methylcrotonyl CoA carboxylase (also called 3-methylcrotonylglycinuria) is described. Two children presented with a metabolic acidosis, one in the neonatal period and the other with episodes of acidosis that started in the second year of life. In the other 2 children neurological symptoms were prominent, one having infantile spasms and the other developmental regression with a skin rash and alopecia. Three of the children responded well to oral biotin and dietary protein restriction but the fourth, despite a biochemical response to biotin, has a severe neurological handicap. The clinical presentation of inborn errors of 3-methylcrotonyl CoA carboxylase is variable. Metabolic acidosis may not be conspicuous and instead neurological features may predominate.