A simple technique to rule out occlusion of right coronary artery after aortic valve surgery

Mechanical occlusion of the right coronary artery during aortic valve surgery is an infrequent but serious complication. Early recognition and expeditious management are important to reduce mortality. We developed a safe, quick, and easy technique to assess right coronary artery flow after aortic valve surgery. Direct intraoperative right coronary artery flow was measured by placing a transit-time flowmeter probe around the right coronary artery. We were able to promptly detect severe right coronary artery insufficiency in patients with acute unexpected right ventricular failure after aortic valve replacement.     

Predicting fractures in an international cohort using risk factor algorithms without BMD

Clinical risk factors are associated with increased probability of fracture in postmenopausal women. We sought to compare prediction models using self‐reported clinical risk factors, excluding BMD, to predict incident fracture among postmenopausal women. The GLOW study enrolled women aged 55 years or older from 723 primary‐care practices in 10 countries. The population comprised 19,586 women aged 60 years or older who were not receiving antiosteoporosis medication and were followed annually for 2 years. Self‐administered questionnaires were used to collect data on characteristics, fracture risk factors, previous fractures, and health status. The main outcome measure compares the C index for models using the WHO Fracture Risk (FRAX), the Garvan Fracture Risk Calculator (FRC), and a simple model using age and prior fracture. Over 2 years, 880 women reported incident fractures including 69 hip fractures, 468 “major fractures” (as defined by FRAX), and 583 “osteoporotic fractures” (as defined by FRC). Using baseline clinical risk factors, both FRAX and FRC showed a moderate ability to correctly order hip fracture times (C index for hip fracture 0.78 and 0.76, respectively). C indices for “major” and “osteoporotic” fractures showed lower values, at 0.61 and 0.64. Neither algorithm was better than the model based on age + fracture history alone (C index for hip fracture 0.78). In conclusion, estimation of fracture risk in an international primary‐care population of postmenopausal women can be made using clinical risk factors alone without BMD. However, more sophisticated models incorporating multiple clinical risk factors including falls were not superior to more parsimonious models in predicting future fracture in this population. © 2011 American Society for Bone and Mineral Research     

Acute hypopituitarism in a pregnant patient after cardiac gunshot injury

Sheehan's syndrome is a well described entity that refers to hypopituitarism with pituitary infarction secondary to postpartum shock or hemorrhage. Antepartum pituitary infarction is a very rare condition that has been reported only in patients with longstanding type 1 diabetes mellitus or uncontrolled gestational diabetes. A case of severe, acute hypopituitarism in the setting of hemorrhagic shock from a gunshot wound is presented. Our case report highlights the importance of including hypopituitarism in the differential diagnosis of a critically ill parturient.     

Recurrent total knee arthroplasty dislocation after dorsal meningioma diagnosed

We report on a 68-year-old woman with gonarthrosis who underwent total knee arthroplasty. Having initially achieved a satisfactory result, she developed at 5 months postoperation an irreducible flexion contracture necessitating revision surgery; but no pathological findings were discovered. In the immediate postoperative period, the patient developed a severe spasm of the hamstring muscles and a paralysis of the external popliteal sciatic nerve with a posterior dislocation of the knee. After reduction, an electromyography study showed an alteration in medullary sensitive conduction; and the magnetic resonance image showed a lesion compatible with meningioma. This complication has not been previously described as a consequence of spinal tumor. Technical considerations are described for this rare complication, which remains a serious challenge for the orthopedic surgeon.     

Long-term oral treatment with BAY 41-2272 ameliorates impaired corpus cavernosum relaxations in a nitric oxide-deficient rat model

Study Type – Therapy (case control)
Level of Evidence 3b What’s known on the subject? and What does the study add? Erectile dysfunction is defined as the persistent inability to achieve and/or maintain an erection sufficient for satisfactory sexual performance. Nitric oxide (NO) is the main transmitter released from nitrergic nerves and endothelial cells involved in the erectile erection. NO activates the soluble guanylyl cyclase (sGC) in cavernosal smooth muscle to generate cyclic GMP (cGMP) that in turn promotes relaxation and penile erection. Erectile dysfunction genesis can be attributed to a variety of factors such as stress, ageing, drugs, and certain pathological conditions including arterial hypertension, atherosclerosis, dyslipidemia and diabetes mellitus. Inhibitors of phosphodiesterase‐5 (PDE5) like sildenafil (viagra^TM), vardenafil (levitra^TM) and tadalafil (cialis^TM) remain the main oral therapy for erectile dysfunction. These compounds inhibit the cGMP hydrolysis thereby preserving cGMP thus causing an enhancement of corporeal smooth muscle relaxation. The existence of a new NO‐independent regulatory site on sGC has been described. BAY 41‐2272 is a novel compound that generates significant amounts of cGMP by stimulating the sGC in the absence of NO. Compound BAY 41‐2272 also synergize with endogenous NO producing higher cGMP‐dependent cell responses. Using a model of chronic NO deficiency in rats to produce erectile dysfunction, we show that long‐term oral treatment of with BAY 41‐2272 prevents the erectile dysfunction in the NO‐deficient rats. Therefore, this compound may have great therapeutic potential to erectile dysfunction treatment.

OBJECTIVE

? To investigate the potential beneficial effects of 4‐week oral treatment with 5‐cyclopropyl‐2‐[1‐(2‐fluoro‐benzyl)‐1Hpyrazolo[3,4‐b]pyridin‐3‐yl]‐pyrimidin‐4‐ylamine (BAY 41‐2272), a nitric oxide (NO)‐independent soluble guanylate cyclase activator, on impaired rat corpus cavernosum relaxations in NO‐deficient rats.

MATERIAL AND METHODS

? Male Wistar rats were divided into four groups: Control, N (G)‐nitro‐L‐ arginine methyl ester (L‐NAME; 20 mg/rat/day), BAY 41‐2272 (20 mg/kg/day) and L‐NAME + BAY 41‐2272. ? Rats were treated with L‐NAME concomitantly with BAY 41‐2272 for 4 weeks. ? Concentration–response curves to acetylcholine (ACh) and sodium nitroprusside (SNP), along with the nitrergic relaxations (1–32 Hz) were obtained in rat corpus cavernosum (RaCC). ? The RaCC contractile responses to the α₁‐adrenoceptor agonist phenylephrine (PE) were obtained.

RESULTS

? Acetylcholine (0.01–1000 µmol/L) produced concentration‐dependent relaxing responses in RaCC that were significantly enhanced (P < 0.05) in BAY 41‐2272‐treated rats. ? The ACh‐induced relaxations were largely reduced in L‐NAME‐treated rats, and co‐treatment with BAY 41‐2272 failed to significantly modify these impaired relaxations. ? The SNP‐induced relaxations were modified neither by L‐NAME nor by co‐treatment with BAY 41‐2272. ? The nitrergic relaxations were significantly amplified in BAY 41‐2272‐treated rats (at 16 and 32 Hz). A significant reduction in the nitrergic relaxations was observed in L‐NAME‐treated rats, an effect largely restored by co‐treatment with BAY 41‐2272. ? The contractile RaCC responses produced by PE (0.001–100 µmol/L) were significantly higher (P < 0.05) in L‐NAME‐treated rats, and co‐treatment of L‐NAME with BAY 41‐2272 nearly restored these enhanced contractile responses.

CONCLUSION

? Four‐week therapy with BAY 41‐2272 prevents the impaired corpus cavernosum relaxations of rats treated chronically with L‐NAME, indicating that accumulation of cyclic guanosine monophosphate into erectile tissue counteracts the NO deficiency.     

Contribution of Jan Brod to nephrology

Jan Brod (1912-1985), Professor of Medicine of Charles University, Prague, was one of the outstanding personalities of the Czechoslovak medicine and European nephrology of the 20th century. He was an eminent clinician, teacher and scientist who belonged among the founders of renal medicine in Europe. He grew up in the scientific tradition of Prague and Vienna and he was trained by some outstanding personalities, particularly Paul Wood. He became famous due to his pathophysiological-clinical approach to hypertension, heart and kidney diseases. He was not only interested in renal and cardiac physiology but in the entire clinical nephrology. He was among the first clinicians who started to use creatinine clearance in routine practice. His early work was also performed in the field of acute glomerulonephritis and in interstitial nephritis. Later he was interested in water and electrolytes in heart failure and the pathogenesis of edema, and he published priority data on the hemodynamic pattern in emotional stress. Furthermore, it is for sure that he was one of the first cardionephrologists, too. As early as in 1950, he studied diurnal variation in renal perfusion and urinary output in heart failure and later the effect of the adrenergic blockade on the renal hemodynamics in heart failure. Up to his exile in 1968, he served as the head of the Institute for Cardiovascular Research based in Prague and later on, up to his retirement, as the head of the Department of Nephrology in Hannover. He was a founding member of the International Society of Nephrology and president of its 2nd congress held in Prague in 1963. Throughout his life, Jan Brod remained a political man who voiced his opinions. Despite two exiles, he was always the Czech patriot. He holds a special place in the history of Czechoslovak and European nephrology.     

Venous outflow obstruction after orthotopic liver transplantation: use of a breast implant to maintain graft position

Hepatic venous outflow obstruction (HVOO) is a rare complication after orthotopic liver transplantation (OLT) usually related to technical issues or to malposition or kinking of the hepatic graft. When HVOO is diagnosed during the early post-transplant period, surgical options are technically very demanding and outcomes discouraging. Therefore, angioplasty and stent placement have been indicated to avoid a chronic lesion of the graft. Three cases of HVOO after OLT are reported. HVOO was diagnosed during the early post-transplant period and was due to graft malposition in two patients and kinking of the vena cava anastomosis in one. All patients were successfully treated with a 300-cc gel-filled breast implant surgically placed in the right hepatic fossa with the liver graft resting on it. Massive ascites in all three patients disappeared and renal impairment resolved within two wk post-implant placement. No prosthesis-related complications have been observed after a follow-up ranging from 30 to 58 months. We describe a simple and effective method of maintaining the liver graft in an adequate position to achieve prolonged relief of the outflow obstruction for the whole graft and discuss the advantages of a breast implant over stent placement or the use of different balloon catheters.     

Massive acetabular bone loss: Limits of trabecular metal cages

Massive acetabular bone loss (more than 50% of the acetabular area) can result in insufficient native bone for stable fixation and long-term bone ingrowth of conventional porous cups. The development of trabecular metal cages with osteoconductive properties may allow a more biological and versatile approach that will help restore bone loss, thus reducing the frequency of implant failure in the short-to-medium term. We report a case of massive bone loss affecting the dome of the acetabulum and the ilium, which was treated with a trabecular metal cage and particulate allograft. Although the trabecular metal components had no intrinsic stability, they did enhance osseointegration and incorporation of a non-impacted particulate graft, thus preventing failure of the reconstruction. The minimum 50% contact area between the native bone and the cup required for osseointegration with the use of porous cups may not hold for new trabecular metal cups, thus reducing the need for antiprotrusio cages. The osteoconductive properties of trabecular metal enhanced allograft incorportation and iliac bone rebuilding without the need to fill the defect with multiple wedges nor protect the reconstruction with an antiprotrusio cage.