Balloon aortic valvuloplasty for aortic stenosis in neonates, children, and young adults

Balloon aortic valvuloplasty is a safe and effective treatment for aortic stenosis in neonates, children, and young adults. The indication for balloon valvuloplasty in children is a peak systolic gradient > 70 mmHg or > 50 mmHg in any patient with symptoms. Published results indicate that the procedure results in an acute reduction in gradient ranging from 49%-70%, and this reduction appears to persist through at least an intermediate follow-up. The percentage reduction in gradient is similar for neonates as well as older children. In neonates, it is imperative to evaluate the size of the left ventricle prior to balloon valvuloplasty since mortality is highest in those with variants of hypoplastic left heart syndrome. Though morbidity and mortality is higher in the neonatal age group, the results are similar to those following surgical intervention. In children older than 1 month of age, the major complication is the development of aortic regurgitation, although it usually appears to be well-tolerated. Previous surgical valvotomy is not a contraindication to balloon aortic valvuloplasty. In the current era, we believe that balloon aortic valvuloplasty should be considered as the first option in neonates, children and young adults with significant aortic valve obstruction.     

Ventricular function

Multiple modalities contribute to the evaluation of ventricular function. The role of cineangiography, echocardiography, MR imaging, ultrafast CT, and nuclear medicine continue to evolve and improve our understanding of the physiology and pathophysiology of ventricular function. This article discusses the use and limitation of each modality.     

Free fatty acids impair hepatic insulin extraction in vivo

Hyperinsulinemia is a common finding in obesity and results from insulin hypersecretion and impaired hepatic insulin extraction. In vitro studies have shown that free fatty acids (FFAs), which are often elevated in obesity, can impair insulin binding and degradation in isolated rat hepatocytes. To investigate whether FFAs impair hepatic insulin extraction (E(H)) in vivo, either saline (SAL) or 10% Intralipid (0.03 ml x kg(-1) x min(-1)) plus heparin (0.44 U x kg(-1) x min(-1)) (IH) was infused into normal dogs to elevate FFA levels. Insulin was infused intraportally at 18 pmol x kg(-1) x min(-1) for 150 min (period A, high insulin dose), and then at 2.4 pmol x kg(-1) x min(-1) for another 150 min (period B, low insulin dose). After the low portal insulin dose, additional insulin was infused peripherally at 8.4 pmol x kg(-1) x min(-1) for 120 min (period C) to assess the clearance of insulin from the peripheral plasma. In 16 paired experiments, FFA levels were 1,085 +/- 167, 1,491 +/- 240, 1,159 +/- 221 micromol/l (IH) and 221 +/- 44, 329 +/- 72, 176 +/- 44 micromol/l (SAL) in periods A, B, and C, respectively. Peripheral insulin levels were greater with IH (P < 0.001) than with SAL in all periods (1,620 +/- 114, 126 +/- 12, 1,050 +/- 72 pmol/l for IH vs. 1,344 +/- 168, 96 +/- 4.2, 882 +/- 60 pmol/l for SAL). Glucose clearance was impaired by IH in all periods (P < 0.05), whereas glucose production was slightly increased by IH during period B. Peripheral insulin clearance (Cl) and E(H) were calculated from the insulin infusion rate and insulin concentration data in each period by taking into account the nonlinearity of insulin kinetics. Cl was lower (P < 0.01) with IH (9.6 +/- 0.6, 12.0 +/- 0.9, 10.2 +/- 0.6 ml x kg(-1) x min(-1)) than with SAL (11.2 +/- 1, 13.6 +/- 0.7, 11.9 +/- 0.9 ml x kg(-1) x min(-1)) in periods A, B, and C. E(H) was also lower (P < 0.05) with IH (25 +/- 4, 40 +/- 5, 32 +/- 5%) than with SAL (30 +/- 2.8, 47 +/- 3, 38 +/- 3%). We conclude that FFAs can impair hepatic insulin extraction in vivo at high and low insulin levels, an effect that may contribute to the peripheral hyperinsulinemia of obesity.     

Carcinoma of the maxillary antrum — A 10 year experience

A retrospective analysis was performed of 250 cases of carcinoma of the maxillary antrum seen over a 10 years period (1975–1984). 98.24% patients were seen in T3 and T4 stages (UICC 1985). 40.7% patients presented with clinically palpable nodes. 42.9% patients were treated by radical radiation and 18.6% by a combination of preoperative radiation followed by surgery. Rest 38.5% patients were treated with palliative intention. Three year disease free survival was 39.58% with radiation alone and 51.91% with combined modality treatment which includes patients salvaged by surgery. Failures were mainly at the local site, 75.86% with radiation alone and 60% with combined modality treatment. Combined modality treatment, preferably preoperative radiation followed by radical surgery, gives the best results in the management of carcinoma of the maxillary antrum.     

Human serum induces apoptosis of xenogenic cardiomyocytes in vivo and in vitro

Abstract: Discordant xenotransplantation is complicated by delayed xenograft rejection (DXR). Previous studies have demonstrated that anti‐apoptotic genes are protective against DXR. This study examines the hypothesis that apoptosis plays a role in human anti‐xenograft responses. C57BL/6 mice and NOD SCID mice were given a single intravenous injection of either a lethal dose (LD, survival < 30 min) or a sublethal dose (SLD) of human serum, and isolated pig and mouse rod‐shaped cardiomyocytes were exposed to human serum in vitro. In situ detection of apoptotic cells in mouse hearts was assessed using a terminal deoxynucleotidyl transferase‐mediated dUTP nicked‐end labeling assay. Mice transfused with human serum had approximately a 10‐fold increased percentage of apoptotic cells after SLD 18 h post‐injection compared with animals given saline, and a fourfold increase over LD. Administration of cobra venom factor (CVF) decomplemented SLD 18 h did not significantly ( P  > 0.05) alter the percentage apoptosis. The addition of 20 mM Gal‐α‐1,3‐Gal to SLD 18 h significantly ( P  < 0.05) reduced percentage apoptosis to levels comparable to saline treated control animals. In vitro using mouse and pig cardiomyocytes demonstrated parallel results as in vivo experiments.
Human serum induces apoptosis of cardiomyocytes in immunocompetent and immunoincompetent mice in vivo, as well as mouse and pig cardiomyocytes in vitro. Further, this apoptotic response can be inhibited by the addition of Gal‐α‐1,3‐Gal without affecting the capacity of the serum to cause HAR. These results demonstrate that a putative human serum factor induces a delayed apoptotic injury of xenograft tissues, and supports the hypothesis that apoptosis may be an important mediator of DXR.     

An unusually severe phenotype for familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is a dominantly inherited predisposition to the development of many hundreds to thousands of adenomatous polyps of the colon. The mean age of onset is around 15 years, symptoms may arise in the third decade, and the median age for the development of colonic cancer is 35-40 years. Prophylactic colectomy reduces the risk of death from colorectal cancer to such an extent that late sequelae such as upper gastrointestinal tumours have become the main cause of mortality in appropriately managed patients. The age at which colonic surveillance begins reflects the natural history of the disease. Onset of polyp formation and cancer in childhood is very unusual, but has recently been associated with a specific mutation at codon 1309 in exon 15 where a more severe phenotype is sometimes observed. The case histories of two families are reported in which there is childhood onset of polyps in the youngest generation and in one case a carcinoma, in whom mutations have been identified in exon 11 of the APC gene. Several other affected relatives were diagnosed at ages ranging from 5-48 years, some already with a cancer at the time of first screening. Since the aim of screening for colonic polyps is prevention of colonic cancer, family members at risk should be offered genetic assessment and direct mutation testing where this is possible, usually in the early teens. In the absence of a genetic test (the situation in about one third of families) or in a known gene carrier, annual colonoscopy examination is advised from the same age. Clinicians should take note of the family history and be prepared to consider much earlier intervention if symptoms occur in a child with a family history of FAP. Where childhood onset of polyps has occurred, other children at risk in the family must be offered earlier genetic testing and endoscopic surveillance.

     

Tracheoesophageal fistula: New option in management

Tracheoesophageal fistula is a life threatening condition. Patients not managed surgically ultimately die of their disease. Surgical management is the treatment of choice. We present a case of a patient that developed a tracheoesophageal fistula after tracheostomy. Surgical repair was done which failed due to infection. The patient was managed with the help of an esophageal stent and Trichloroacetic Acid cautery. This approach can be used in selected patients, depending upon the size and site of TEE Larger fistulae and those situated lower down e.g. supra carinal cannot be managed by this technique.     

Anterior lumbar interbody fusion with osteoinductive growth factors

Anterior intervertebral fusion increasingly is used as a treatment for discogenic or intersegmental pathologic diseases of the lumbar spine. This is in part attributable to the evolution and refinement of laparoscopic and minimally invasive surgical techniques that now can be used to access the anterior spinal column. It also is attributable to the availability of newer generation intervertebral fixation devices such as the threaded titanium cages or threaded allograft bone dowels, both of which are technically simpler to implant. Recently, limited clinical studies of intervertebral lumbar fusion have examined the use of these devices combined with osteoinductive growth factors as substitutes for autogenous bone graft. Early clinical results of lumbar fusion using threaded intervertebral implants filled with recombinant human bone morphogenetic protein-2 have been favorable. Higher fusion rates, shorter operative times, and shorter hospital stays have been reported in the initial series. Clinical trials involving larger cohorts with various spinal applications for osteoinductive molecules currently are in progress.