Transmural atrial fibrosis after epicardial and endocardial argon-powered CryoMaze ablation.

BACKGROUND: The CryoMaze procedure is usually limited to endocardial ablation under cardio-pulmonary bypass. Epicardial ablation is considered inferior as endocardial islets of atrial tissue could theoretically remain viable, protected from cryoinjury by epicardial fat and endocardial circulating warm blood. Novel argon-powered cryoprobes with lower ablation temperatures have recently become available. It is unclear if these instruments can reliably induce transmural atrial fibrosis by epicardial cryoablation on the beating heart. METHODS: Ten sheep were divided into two equal groups. CryoMaze ablations were applied using an argon-powered cryoprobe with an ablation temperature of -185°C. In the control group, standardized ablations (n = 50) were applied endocardially under cardiopulmonary bypass. In the experimental group, corresponding ablations (n = 50) were applied epicardially on the beating heart. Postoperatively the animals were monitored for 30 days. At necropsy, the lesions were explanted and analyzed histologically for evidence of transmural fibrosis. RESULTS: Two animals in the control group and one animal in the experimental group died prematurely. Autopsy of the remaining animals showed that all lesions (n = 70) had retained their structural integrity. In the control group, histology demonstrated transmural fibrosis in 94% (28/30) of the endocardially applied lesions. In the experimental group, histology demonstrated transmural fibrosis in 95% (38/40) of the epicardially applied lesions. Statistical analysis revealed no significant difference between the two groups (p = 0.96). CONCLUSION: Argon-powered epicardial cryoablation on the beating heart is as efficient in inducing transmural fibrosis as the traditional technique of endocardial ablation under cardio-pulmonary bypass.

Development and early results of a new patellofemoral arthroplasty.

UNLABELLED: A new patellofemoral arthroplasty is described, based on a previous design of total knee arthroplasty. The indications are for patients with specific isolated patellofemoral disease with advanced chondral or arthritic damage. The design and technique of insertion is detailed. Three hundred six patellofemoral arthroplasties have been done in 240 patients. The initial results show a high level of pain relief and improvement in function. Two-year followup is available for treatment of 124 knees and 5-year followup is available for treatment of 33 knees. There has been no deterioration in pain or function with followup to 5 years, and there were no late complications attributable to the arthroplasty. Disease progression in the tibiofemoral joint has occurred in 14 patients (16 knees, 5%) requiring revision in 10 of these patients (11 knees, 3.6%). Persistent anterior knee pain was recorded in 14 knees (4%). The short-term results using this new design were better than those of the prosthesis that we used previously, especially concerning malalignment and wear. It offers a reasonable alternative to total knee replacement in the small group of patients with isolated patellofemoral disease. LEVEL OF EVIDENCE: Therapeutic study, Level II (prospective cohort study). See the Guidelines for Authors for a complete description of levels of evidence.

Comparative evaluation of specific ELISA and RFFIT antibody assays in the assessment of dog immunity against rabies.

Two techniques are currently used to evaluate the humoral immune responses to rabies vaccination: ELISA, which detects binding antibodies to viral antigens and the WHO reference rapid fluorescent focus inhibition test (RFFIT), which assays in vitro virus-neutralizing antibodies. In this study, we have comparatively evaluated antibody responses of dogs reared either in an experimental kennel or living in field conditions after vaccination with a cell culture-derived rabies vaccine. In experimental conditions, both ELISA and RFFIT techniques were well correlated. However, in field conditions, they yielded discrepant results particularly in evaluating the residual rabies immunity before vaccine administration and in identifying seroconverted dogs. After rabies vaccination in field conditions, while similar antibody titres and seroconversion rates were obtained using either technique, the discrimination of a given dog according to the seroconversion threshold depended on the assay. We concluded, that whereas in experimental conditions, ELISA and RFFIT were well correlated, in field conditions ELISA yielded upper estimates. Consequently, RFFIT, although a cumbersome test, should continue to be considered as the reference rabies antibody assay technique. A seroconversion threshold of 0.5 IU/ml should be cautiously considered and a higher threshold (1 IU/ml) could be more appropriate in the evaluation of rabies immunity in the field in order to marginalize the interfering factors.

Long-term follow-up of unilateral pallidotomy in advanced Parkinson's disease.

BACKGROUND: Although the short-term benefits of posteroventral pallidotomy for patients with advanced Parkinson's disease have been well documented, little is known about the long-term outcome of the procedure. METHODS: We conducted a long-term follow-up study of a cohort of 40 patients who had undergone unilateral posteroventral medial pallidotomy between 1993 and 1996. Twenty patients were not evaluated because they had undergone a second surgical procedure (11 patients) or had died (2) or because they had dementia or another debilitating illness (4), lived too far away (1), or had been lost to follow-up (2). We conducted serial postoperative assessments of parkinsonism in the remaining 20 patients while they were taking medications ("on" period) and after overnight withdrawal of the drugs ("off" period). The mean follow-up time was 52 months (range, 41 to 64). RESULTS: The combined off-period score for activities of daily living and motor function on the Unified Parkinson's Disease Rating Scale was 18.0 percent better at the last evaluation than at base line (95 percent confidence interval, 4.9 to 31.0 percent; P=0.01). Significant improvements were also evident in the off-period scores for contralateral tremor (65.4 percent improvement, P=0.007), rigidity (43.2 percent, P=0.03), and bradykinesia (18.2 percent, P=0.04) and in the on-period score for contralateral dyskinesia (70.6 percent, P<0.001). Changes in medication did not contribute to the sustained improvement. The 20 patients who could not be included in the long-term analysis had similar base-line characteristics but a worse response to surgery at six months. CONCLUSIONS: In the group of patients with advanced Parkinson's disease who could be enrolled in our long-term follow-up study of unilateral posteroventral medial pallidotomy (20 patients from the original cohort of 40), significant early improvements in off-period contralateral signs of parkinsonism were sustained for up to five and a half years. There was a sustained significant improvement in on-period contralateral dyskinesia but not in other on-period signs of parkinsonism.

Five-year experience in using coil embolization for ruptured intracranial aneurysms: outcomes and incidence of late rebleeding.

OBJECT: During a 5-year period 317 patients presenting with aneurysmal subarachnoid hemorrhage were successfully treated by coil embolization within 30 days of hemorrhage. The authors followed patients to assess the stability of aneurysm occlusion and its longer-term efficacy in protecting patients against rebleeding. METHODS: Patients were followed for 6 to 65 months (median 22.3 months) by clinical review, angiography performed at 6 months posttreatment, and annual questionnaires. Stable angiographic occlusion was evident in 86.4% of small and 85.2% of large aneurysms with recurrent filling in 38 (14.7%) of 259 aneurysms. Rebleeding was caused by aneurysm recurrence in four patients (between 11 and 35 months posttreatment) and by rupture of a coincidental untreated aneurysm in one patient. Annual rebleeding rates were 0.8% in the 1st year, 0.6% in the 2nd year, and 2.4% in the 3rd year after aneurysm embolization, with no rebleeding in subsequent years. Rebleeding occurred in three (7.9%) of 38 recurrent aneurysms and in one (0.4%) of 221 aneurysms that appeared stable on angiography. CONCLUSIONS: Periodic follow-up angiography after coil embolization is recommended to identify aneurysm recurrence and those patients at a high risk of late rebleeding.

Infections in craniofacial surgery: a combined report of 567 procedures from two centers.

This retrospective review of infectious complications was undertaken at two craniofacial centers (Dallas and Philadelphia). Fourteen infections were identified over a 6.5-year period in 567 intracranial procedures primarily for craniosynostosis. There were no infections in infants under 13 months of age and no cases of meningitis. The overall infection rate was 2.5 percent, and 85 percent of infections occurred in secondary reoperative cases. Tracheostomies were not identified as a risk factor for infection. No difference was found in infection rates between patients with shaved and unshaved scalps. Candida and Pseudomonas were the two most common organisms identified, and 28 percent of our infections involved yeast. The average time to diagnose infection was 11.5 days (excluding three patients who averaged 5 months). Thirteen of the fourteen infections were treated surgically with placement of a subgaleal irrigation/drainage system. Initial bony debridement was kept to a minimum. Based on our findings, recommendations are made to further lower infection rates, particularly those caused by opportunistic organisms.

Management of bile duct injuries and strictures following cholecystectomy.

During 7057 conventional cholecystectomies (1972-1991), 16 bile duct injuries occurred, amounting to a risk of 0.22%. A total of 1022 laparoscopic cholecystectomies were performed without such a complication since April 1990. In a retrospective study, 64 patients (16 of our patients and 48 referrals) with an injury or stricture due to conventional cholecystectomy were investigated. In 14 of our 16 patients the injury was recognized and immediately repaired with a good long-term result of 93%, including one successful repair of a subsequent stricture. Two cases of unrecognized injury were managed by nonoperative means. The group of 48 referred patients comprised 10 early postoperative complications (21%) and 38 strictures after an "uneventful" cholecystectomy. Of the 64 total patients, 10 (16%) underwent nonoperative treatment, and 54 required surgery. The mean follow-up period after surgery was 7.4 +/- 4.9 years. Most cases (93%) were repaired by bilioenteric anastomosis (i.e., foremost hepaticojejunostomy) with an 18% restricture rate. Including second and third repairs for restricture, a total of 60 operations (14 primary and 46 secondary reconstructions) were performed without hospital mortality. A good long-term result after stricture repair was achieved in 75% of the patients, whereas 17% had a poor outcome owing to restricture or death (10% had related mortality within 10 years). The other 8% had a moderate result due to recurrent cholangitis. Thus immediate repair of a bile duct injury offers the better chance of a favorable prognosis compared to secondary stricture repair.

The incidence of cutaneous larva migrans in Montserrat, Leeward Islands, West Indies

This report describes a retrospective analysis of case recordes of cutaneous larva migrans in Montserrat. An estimated incidence of 0.064% was found betweed mid-1977 and mid-1978

Terapia antiplaquetaria despues de cirugia coronaria / Antiplatelet therapy after coronary surgery

El tratamiento post-operatorio con drogas antiplaquetarias ha demostrado ser benefico para prevenir la obstruccion de injertos venosos utlizados en cirugia coronaria. Este estudio analiza 2 grupos de pacientes, uno (212) si terapia antiplaquetaria y el otro (205) con antiplaquetarios. Se encontro una diferencia importante en la recurrencia clinica de la angina post-operatoria. Se discute la fisiopatologia en la oclusion post-operatoria temprana y tardia de los injertos y el efecto de los medicamentos antiplaquetarios en la prevencion de ese fenomeno

Niveles de hemoglobina y cirugia coronaria: II. Relacion entre concentracion de hemoglobina y angina recurrente despues de cirugia coronaria / Hemoglobin levels and coronary surgery: II. Relationship between hemoglobin concentration and reccurrent angina after coronary surgery

Con el objeto de probar la relacion existente entre bajas concentraciones de hemoglobina y menor riesgo de trombosis despues de cirugia coronaria, y en esta forma menor incidencia de angina recurrente, hemos tomado en cuenta los niveles de hemoglobina en 212 pacientes sometidos a cirugia de injerto aorto-coronario (bypass). La incidencia de angina recurrente encontrada en enfermos con niveles altos de hemoglobina (alrededor de 13-14 g%) fue significativamente mayor en comparacion con aquellos que tuvieron concentraciones relativamente bajas (alrededor de 11 g%), con una significancia estadistica de p<0,001.

Hemodynamic and metabolic evaluation of an acute left ventricular failure model induced by coronary artery embolization

Existe uma necessidade de um modelo experimental reproduzível e estável da insuficiência cardíaca aguda. Neste estudo, realizado em 56 cäes, avaliamos os efeitos hemodinâmicos e metabólicos da insuficiência ventricular esquerda, produzidos por embolia via artéria coronária principal esquerda com microsferas plásticas de 50 micrometros. Foram excluídos 15 cäes que apresentaram tanto arritmias como hemodinâmica instável. Nos 41 cäes restantes, a embolia causou aumento gradativo da pressäo endodiastólica final do ventrículo esquerdo de 5,6 ñ 0,3 (média ñ EPM) para 14,8 ñ 0,4 mmHg, diminuiçäo da dP/dt max ventricular esquerda de 2627 ñ 81 para 1812 ñ 46 mmHg/s, reduçäo do débito cardíaco (28%), queda da pressäo sistêmica arterial (9%) e aumento da resistência vascular periférica total (31%) (todos p < 0,01, n = 41). O consumo de oxigênio do miocárdio foi reduzido em 36% (p < 0,01, n = 41), o lactato do miocárdio declinou de 43,1 ñ 5,3 para 8,4 ñ 5,3 micromol/1 e a absorçäo dos ácidos graxos no miocárdio foi reduzida em 42% p < 0,01, n = 22). O total da necrose ventricular esquerda foi estimado após 24 horas, atraves de uma técnica que emprega o corante trifenil terazólio. Neste grupo, 41% ñ 3 do ventrículo esquerdo estavam necrosados, existindo boa correlaçäo entre a extensäo da necrose e a pressäo endodiastólica final do ventrículo esquerdo (r = 0,75, n = 12, p < 0,01). Concluindo, a embolia via artéria coronária principal esquerda provocou um modelo reproduzível e estável da insuficiência ventricular esquerda, em cäes. A pressäo endodiastólica final do ventrículo esquerdo parece refletir a extensäo da necrose miocárdica neste modelo

Paratesticular rhabdomyosarcoma

A case of paratesticular rhabdomyosarcoma is described, the first example of this rare tumour to be reported from Trinidad. The recent use of a combined treatment regime with surgery, radiotherapy and chemotherapy has dramatically improved the prognosis in this previously lethal tumour. At present, about 80 percent of the cases reported are alive and well after five years (AU)

Magnesium balance studies in marasmic kwashiorkor

Studies of magnesium balance were made on 3 Jamaican infants during recovery from marasmic kwashiorkor. Analysis of muscle biopsy specimens indicated a marked deficit of magnesium as well as potassium in all cases. The serum magnesium level was slightly low in one case. A positive magnesium balance was maintained for several weeks in recovery and was accompanied by low urinary excretion. In one case there was considerable intestinal absorption of magnesium, even in the presence of diarrhea. Efficient absorption of a high oral suppliment tended to overcome renal conservation. Previous analysis has suggested that the deficiency of intracellular electrolytes in wet muscle samples is due partly to the reduced intracellular volume associated with protein loss and partly to a true electrolyte deficit. The positive magnesium balance in recovery is therefore attributable both to intracellular repletion and to tissue growth; the latter tends to be masked clinically by loss of excess body water. Little is known of the additional factor of the repletion of magnesium in bone, but the evidence from animal experiments is that the deficit in bone may be very substantial (AU)