Aortic arch repair: let it beat!

Objective aortic arch repair (AAR) on the beating heart may reduce cross-clamping times and offer improved postoperative cardiac function.Methods A single-center review of all patients (n = 24) who underwent surgical AAR during biventricular repair between 01/2006 and 01/2008 was done. All patients were operated on under cardiopulmonary bypass (CPB) with antegrade cerebral perfusion (ACP). During AAR, 13 patients (group 1) received cardioplegic arrest, and were compared to 11 patients (group 2) who underwent a beating-heart modification with selective myocardial perfusion. Seventeen patients had additional intracardiac lesions and underwent simultaneous correction during the procedure.Results Durations of CPB, AAR and ACP did not differ statistically between groups. Cardioplegic arrest time was significantly lower in group 1 (34 ± 13 vs. 76 ± 11 min, p = 0.02) and resulted in a subsequent reduction of myocardial ischemic damage as borne out by lower postoperative levels of troponin T and CK-MB (2.5 ± 0.7 vs. 7.1 ± 1.4 ng/mL, p = 0.02; 68.7 ± 11.5 vs. 149.1 ± 27.2 U/l, p = 0.03). We observed an enhanced patient recovery with shorter inotropic and ventilatory support times (p < 0.05).Conclusion Pediatric aortic arch correction on a CPB beating heart with selective myocardial perfusion is technically feasible and safe. The reduction of the myocardial ischemic time is effective and results in less myocardial damage.     

Percutaneous AAA repair: is it safe?

PURPOSE: To assess if percutaneous insertion of large-bore sheaths is safe during endovascular repair (EVR) for abdominal aortic aneurysms (AAA). METHODS: Ninety-five AAA patients undergoing EVR had the endografts implanted percutaneously via 14-F to 20-F sheaths in a prospective nonrandomized study. Vascular sutures were applied bilaterally to the common femoral arteries using a vascular closure device; the sutures were tied after sheath withdrawal. Blood loss, operative time, and length of stay (LOS) were compared to 26 AAA patients undergoing EVR with bilateral femoral cutdowns before the percutaneous technique was available. Follow-up included duplex ultrasonography and clinical examination. RESULTS: Bilateral percutaneous closure of the femoral arteries was successful in 78 (82%) patients. Fifteen patients required arteriorrhaphy intraoperatively and 2 others within 24 hours. The failure rate was 20%, 0%, 3%, and 7% for the 20-F, 18-F, 16-F, and 14-F introducers, respectively. Blood loss was 400 mL (range 0-1800) in successful cases, 900 mL (range 0-3000) in failures (p<0.0001). One deep infection at the puncture site required thrombectomy and patchplasty; no other late complication occurred. There was no significant difference in operative time, blood loss, and LOS between patients treated with percutaneous EVR and those with primary femoral exposure. CONCLUSIONS: Percutaneous transfemoral EVR of AAA using large-bore introducer sheaths is safe. More than three quarters of the patients avoid femoral cutdown. Late complications are rare.     

External fixation for the fracture repair

External fixation has made remarkable progress in the field of orthopaedic surgery in recent years. The concept of distraction histogenesis made it possible to treat for the difficult case without bone graft, such as shortening and deformities of the limbs, pseudarthrosis, bone loss and osteomyelitis etc. These advances have led to the cure of many unsolved fractures. It is likely that external fixators are constantly being improved and the method of fracture repair will progress in the future.     

Adrenarche in nonhuman primates: the evidence for it and the need to redefine it

Adrenarche is most commonly defined as a prepubertal increase in circulating adrenal androgens, dehydroepiandrosterone (DHEA) and its sulfo-conjugate (DHEAS). This event is thought to have evolved in humans and some great apes but not in Old World monkeys, perhaps to promote brain development. Whether adrenarche represents a shared, derived developmental event in humans and our closest relatives, adrenal androgen secretion (and its regulation) is of considerable clinical interest. Specifically, adrenal androgens play a significant role in the pathophysiology of polycystic ovarian disease and breast and prostate cancers. Understanding the development of androgen secretion by the human adrenal cortex and identifying a suitable model for its study are therefore of central importance for clinical and evolutionary concerns. This review will examine the evidence for adrenarche in nonhuman primates (NHP) and suggest that a broader definition of this developmental event is needed, including morphological, biochemical, and endocrine criteria. Using such a definition, evidence from recent studies suggests that adrenarche evolved in Old World primates but spans a relatively brief period early in development compared with humans and some great apes. This emphasizes the need for frequent longitudinal sampling in evaluating developmental changes in adrenal androgen secretion as well as the tenuous nature of existing evidence of adrenarche in some species among the great apes. Central to an understanding of the regulation of adrenal androgen production in humans is the recognition of the complex nature of adrenarche and the need for more carefully conducted comparative studies and a broader definition in order to promote investigation among NHP in particular.     

Beta-catenin expression in hepatocellular carcinoma: a possible participation of beta-catenin in the dedifferentiation process

BACKGROUND: beta-Catenin is known as a multifunctional protein acting as a regulator of the cadherin-mediated cell-cell adhesion system and in the Wingless/Wnt signal transduction pathway. Recent studies reported mutation of the beta-catenin gene in some tissues of hepatocellular carcinoma (HCC). METHODS: 'Nodule-in-nodule' appearance is a feature of well-differentiated HCC containing a distinct nodule of less-differentiated cancer tissue inside, and it is presumed to be a morphological expression of the dedifferentiation process. The present study immunohistochemically investigated the beta-catenin expression according to the dedifferentiation process of HCC, that is, in small well-differentiated HCC with indistinct margins, HCC with a 'nodule-in-nodule' appearance, moderately differentiated HCC, which does not have a 'nodule-in-nodule' appearance, and sarcomatous HCC. RESULTS: The expression of beta-catenin was observed in approximately 70% of small well-differentiated HCC with indistinct margins. In HCC with a 'nodule-in-nodule' appearance, membranous expression of beta-catenin was higher in the well-differentiated cancer tissues than in the less-differentiated cancer tissues (P < 0.01), cytoplasmic expression was higher in the less-differentiated cancer tissues (P < 0.01), and nuclear expression was higher in the less-differentiated cancer tissues (P < 0.001). In moderately differentiated HCC, tumors with membranous expression of beta-catenin had more frequent intrahepatic metastasis than those without having the expression (P < 0.001). CONCLUSIONS: Accumulation of beta-catenin was already present in the early stage of HCC, and in less-differentiated cancer tissue the membranous expression of beta-catenin could be related to intrahepatic metastasis.     

Hip fracture in the older patient: reasons for delay in hospitalization and timing of surgical repair

OBJECTIVES: To quantify the interval between injury and hospitalization in older hip fracture patients, to quantify the time from hospital arrival to surgical repair of hip fracture, and to describe factors contributing to extended intervals between injury, hospitalization, and surgical repair of hip fracture. DESIGN: Prospective cohort study. SETTING: Four hospitals in the New York City metropolitan area. PARTICIPANTS: Consecutive patients aged 50 and older admitted with diagnosis of hip fracture to these four hospitals between August 1997 and August 1998. MEASUREMENTS: Time of injury, time of arrival to the emergency room, and time of surgery were recorded and used to calculate intervals between injury and hospital arrival and between hospital arrival and surgical repair. RESULTS: Of the 571 patients enrolled, 99 (17%) arrived at the hospital more than 24 hours after injury. After hospital arrival, 17 (3%) patients did not have surgery, 166 (29%) had surgery within 24 hours of arrival, and 388 (68.0%) had surgery more than 24 hours after arrival (median 41 hours, range 25-584). For those patients who had surgery after 24 hours, 163 (29.4%) had surgery 25 to 36 hours after hospital arrival, 102 (18.4%) had surgery 37 to 48 hours after arrival, and 123 (22.2%) had surgery more than 48 hours after arrival. The primary reasons for delaying surgery more than 24 hours after hospital arrival were waiting for routine medical clearance (52%) and unavailability of the operating suite or surgeon (29%). Stabilization of associated medical conditions resulted in the lengthiest periods of delay. CONCLUSION: A wait time of more than 24 hours from hospitalization to surgical repair of hip fracture in older patients is common. Some of this delay time is patient related and some occurs because of systems factors and may be avoidable. The extent to which surgical timing affects survival and functional recovery needs more detailed examination.     

Prosthetic joint infection: when to suspect it, how to manage it

The number of prosthetic joint infections in the United States is rising because of our aging population and the increasing number of adults undergoing joint replacement surgery. The cardinal symptom of prosthetic joint infection is recurrent pain in the joint. Fever and leukocytosis may be absent in elderly patients, particularly in late infections. Diagnosis requires joint aspiration or operative biopsy. Successful outcomes require expert orthopedic surgical management and prolonged antibiotic therapy. Treatment should be individualized according to the specific pathogen and clinical circumstances.