Torque Expression in Stainless Steel Orthodontic Brackets: A Systematic Review

Objective:To evaluate the quantitative effects on torque expression of varying the slot size of stainless steel orthodontic brackets and the dimension of stainless steel wire, and to analyze the limitations of the experimental methods used.Materials and Methods:In vitro studies measuring torque expression in conventional and self-ligating stainless steel brackets with a torque-measuring device, with the use of straight stainless steel orthodontic wire without second-order mechanics and without loops, coils, or auxiliary wires, were sought through a systematic review process.Results:Eleven articles were selected. Direct comparison of different studies was limited by differences in the measuring devices used and in the parameters measured. On the basis of the selected studies, in a 0.018 inch stainless steel bracket slot, the engagement angle ranges from 31 degrees with a 0.016 × 0.016 inch stainless steel archwire to 4.6 degrees with a 0.018 × 0.025 inch stainless steel archwire. In a 0.022 inch stainless steel bracket slot, the engagement angle ranges from 18 degrees with a 0.018 × 0.025 inch stainless steel archwire to 6 degrees with a 0.021 × 0.025 inch stainless steel archwire. Active stainless steel self-ligating brackets demonstrate an engagement angle of approximately 7.5 degrees, whereas passive stainless steel self-ligating brackets show an engagement angle of approximately 14 degrees with 0.019 × 0.025 inch stainless steel wire in a 0.022 inch slot.Conclusions:The engagement angle depends on archwire dimension and edge shape, as well as on bracket slot dimension, and is variable and larger than published theoretical values. Clinically effective torque can be achieved in a 0.022 inch bracket slot with archwire torsion of 15 to 31 degrees for active self-ligating brackets and of 23 to 35 degrees for passive self-ligating brackets with a 0.019 × 0.025 inch stainless steel wire.     

Oncologic outcomes of open conservation laryngectomy for radiorecurrent laryngeal carcinoma: a systematic review and meta-analysis of English-language literature

BACKGROUND:

The role of open conservation (partial) laryngeal surgery in radiorecurrent laryngeal cancers is unclear, and the procedure is not widely accepted or practiced. The objective of this review was to assess the oncologic and functional outcomes of partial laryngectomy in radiorecurrent tumors of the larynx reported in the literature.

METHODS:

The systematic review was performed using independently developed search strategies and included Medline, Embase, Zetoc, conference proceedings, and, when appropriate, a manual search. Inclusion criteria for the articles were set a priori. All included articles were subjected to quality assessment. Pooled estimates of local control at 24 months and of disease‐free and overall survival rates were calculated using both a fixed‐effects model (inverse square) and a random‐effects model (DerSimonian‐Laird).

RESULTS:

The search identified 401 publications, of which 26 studies satisfied all inclusion criteria. Ten studies had a quality score ≥6 (good), and 16 had a score of 4 or 5 (fair). The pooled estimates of oncologic outcomes using the random‐effects model were as follows: The local control rate at 24 months for 560 patients was 86.9% (95% CI, 84%‐89.5%), the disease‐free survival rate for 352 patients was 91.2% (95% CI, 88.2%‐93.9%), and the overall survival rate for 360 patients was 83.1% (95% CI, 79.1%‐86.7%). Decannulation of tracheostomy occurred in 95.1% (95% CI, 92.6%‐97.2%) of the patients who were analyzed (n = 315), whereas the pooled mean larynx preservation rate was 83.9% (95% CI, 80.7%‐87%; n = 502)

CONCLUSIONS:

The current results indicated that open partial laryngectomies are oncologically sound procedures in the salvage setting and have a high larynx preservation rate. Cancer 2011. © 2011 American Cancer Society.     

Left ventricular diverticulum mimicking ventricular pseudoaneurysm in an adult

True diverticulum of the left ventricle is very rarely seen in adults: the condition typically occurs in children and can be associated with other anatomic defects that involve the thoracoabdominal midline. Left ventricular diverticulum, which is usually asymptomatic and typically discovered incidentally, can pose a substantial challenge to the surgeon.Herein, we report the case of a 46-year-old man who presented with worsening exertional angina and ST-segment elevation in the inferior electrocardiographic leads. After a stent was deployed in the patient's occluded right coronary artery, left ventriculography revealed outward pouching of the left ventricular inferior wall, suggesting an aneurysm or a contained free-wall rupture. Transesophageal echocardiography showed a sizable defect and a possible intracavitary thrombus. The presumptive diagnosis was a postinfarction subacute pseudoaneurysm of the left ventricle. However, during surgery, we saw no clots, intrapericardial blood accumulation, or perforation. A localized area of thinned muscle in the region of the posterior descending coronary artery was consistent with a ventricular diverticulum. The left ventricular epicardial surface was reinforced with a small bovine pericardial patch. The patient's recovery was uneventful. We discuss the forms of congenital left ventricular diverticulum and offer considerations regarding differential diagnosis.     

Right Ventricular Tissue Doppler and Strain Imaging: Ready for Clinical Use?

Although tissue Doppler (TD) imaging of the left ventricle is now commonly used in clinical settings, TD imaging of the right ventricle (RV) is not routinely practiced. Yet, there are significant data on clinical uses of RV TD imaging, including established normal values using both color and spectral TD. In acute left ventricular (LV) inferior wall myocardial infarction, depressed RV TD velocities have been shown to correlate with the presence of RV impairment, and with patient outcome. In patients with LV heart failure, TD imaging has been correlated to RV ejection fraction by radionuclide angiography, and is an independent predictor of outcome. In patients with congenital heart disease, RV TD has been especially valuable for assessing RV function, and has been correlated to invasive hemodynamic indices, and RV ejection fraction by magnetic resonance imaging. The RV performance (Tei) index has been calculated and validated using TD-derived, rather than conventional pulsed Doppler time intervals. RV TD indices have been shown to be useful in the detection of subclinical and clinical disease in morbid obesity, chronic pulmonary, and systemic disease. TD-derived RV strain imaging can detect segmental myocardial dysfunction, overcoming limitations to conventional TD imaging resulting from tethering. For both TD velocity and strain imaging, however, appreciation of the limitations of these techniques is necessary for their appropriate use. Given its rapid acquisition times, reproducibility, and ease of addition to standard transthoracic echocardiographic protocols, RV TD and strain imaging are important additional modalities in the comprehensive echo-Doppler assessment of RV function.     

National survey of anticoagulation policy in endoscopy

BACKGROUND: Anticoagulated patients who need to undergo endoscopy present unique challenges to the gastroenterologist. The continuation of anticoagulant therapy increases the risk of haemorrhagic complications of gastrointestinal endoscopy. Reversing the anticoagulation increases the risk of thromboembolism. In our experience in various endoscopy units, there are variable policies on the management of anticoagulated patients undergoing gastrointestinal endoscopy. METHODS: To study the current practice, survey questionnaires were sent to 2320 doctors, working in 231 hospitals across the United Kingdom. RESULTS: Responses were obtained from 219 hospitals (94.8%), but only from 434 doctors (18.7%). The results show 40.8% endoscopists continued the patients on warfarin when performing a planned upper gastrointestinal endoscopy, whereas 26% stopped it; 33.2% gave varying reports, that is, they used their own judgement according to the disease for which the anticoagulant was being given. For planned lower gastrointestinal endoscopy, 48.7% doctors preferred to stop warfarin; 53.3% of the endoscopists stated that they have a policy in place at their hospital for both upper and lower gastrointestinal endoscopy in anticoagulated patients; 5.5% had a policy for upper gastrointestinal endoscopy only and 6.2% for lower gastrointestinal endoscopy only. Thirty-five per cent doctors reported that they did not have any standard policy. We compared the responses from within a hospital to see whether the doctors were uniformly aware of an existing policy in their hospital. For upper gastrointestinal endoscopy, the responses were the same (either yes or no) by 51% of the doctors, whereas they were different by 49%. For lower gastrointestinal endoscopies, the same response was given by 49% of the doctors, whereas 51% gave different answers. The poor response rate from the doctors, however, makes firm interpretation of the data difficult. CONCLUSIONS: A wide variation in practice is seen across the country. A robust national guideline to streamline the endoscopy practice in anticoagulated patients is needed.     

Assessment of erectile dysfunction in diabetic patients

Erectile dysfunction (ED) aetiology is multifactorial, including endocrine, neurological, vascular, systemic disease, local penile disorders, nutrition, psychogenic factors, and drug-related. This study was performed to compare the relevant comprehensive biochemical parameters as well as the clinical characteristics in diabetic ED and healthy control subjects and to assess the occurrence of penile neuropathy in diabetic patients and thus the relationship between ED and diabetes. A total of 56 patients accepted to undergo assessment for penile vasculature using intracavernosal injection and colour Doppler ultrasonography. Of the 56 diabetic patients, 38 patients were found with normal blood flow and thus they were considered as the diabetic-ED group, whereas, ED diabetic patients with an arteriogenic component were excluded. These patients with an age range between 17 and 58 years, complaining of ED, with duration of diabetic illness ranging from 2 to 15 years. The Control group comprised of 30 healthy subject aged between 19 and 55 years. Peripheral venous levels of testosterone, prolactin, follicle stimulating hormone (FSH), luteinizing hormone (LH), thyroid stimulating hormone (TSH), malondialdehyde and glycosylated haemoglobin (HbA(1)c) were obtained in all subjects. Valsalva manoeuvre and neurophysiological tests were also determined. Testosterone, prolactine, FSH, LH, and TSH hormones of the diabetic patients were not significantly different from those of the control group. Diabetic patients with ED have higher HbA(1)c and oxidative stress levels while the R-R ratio was significantly decreased. Bulbocavernosus reflex latency was significantly prolonged, whereas its amplitude, the conduction velocity and amplitude of dorsal nerve of penis were significantly reduced in the diabetic patients. We concluded that although ED is a multifactorial disorder, yet, the present study revealed that in ED patients without arteriogenic ED a neurogenic component is present. Furthermore, the complex effect of the Valsalva manoeuvre on cardiovascular function is the basis of its usefulness as a measure of autonomic function. Thus, it can be of value in the diagnosis of ED although these hypotheses require follow-up in a large study cohort.     

Transperitoneal versus retroperitoneal suprarenal cross-clamping for repair of abdominal aortic aneurysm with a hostile infrarenal aortic neck

Infrarenal abdominal aortic aneurysms (AAAs) with a hostile infrarenal aortic neck unfit for endovascular aneurysm repair (EVAR) are more likely to require open repair with suprarenal aortic cross-clamping. We compared the results of the transperitoneal versus retroperitoneal approaches for repair of infrarenal AAA requiring suprarenal cross-clamping and the relative frequency of such techniques after incorporating EVAR into our clinical practice. From January 1998 through September 2005, 478 elective infrarenal aortic aneurysms were repaired. There were 160 (33%) open repairs (71% transperitoneal and 29% retroperitoneal) and 318 (67%) endovascular repairs. In 38 cases (24%) suprarenal cross-clamping was performed (47% transperitoneal and 53% retroperitoneal incisions) for a hostile infrarenal neck. A hostile aortic neck was defined as severe angulation (>60 degrees ), short neck (<15 mm), extensive calcification, or circumferential thrombus. The median age was 70 years; 47% were men; 16% had diabetes mellitus, 29% pulmonary disease, 53% coronary artery disease, and 11% renal insufficiency. The median aneurysm size was 6.0 cm. A retrospective analysis was performed to compare 30-day postoperative outcomes between the trans- and retroperitoneal patient cohorts. The results were determined for two time periods to assess whether open repair with suprarenal cross- clamping was being performed more frequently as a result of increased utilization of EVAR in the contemporary period. After 2002, EVAR increased from 60% to 71% (p = 0.04) while open repair declined from 40% to 29% (p = 0.01). The retroperitoneal approach doubled from 19% to 39%, while the transperitoneal approach decreased from 81% to 61% (p = 0.02). Suprarenal cross-clamping increased by 11% after 2002. There was no significant difference in age, sex, aneurysm size, or comorbidities between the trans- and retroperitoneal groups with suprarenal cross-clamping. The 30-day mortality was 2/38 (5%) and occurred only in the transperitoneal group. The transperitoneal approach was associated with significantly greater blood loss and longer suprarenal cross-clamp times (2,400 vs. 1,800 mL and 38.0 vs. 29.5 min; p = 0.03), but there were no significant differences in 30-day postoperative complications. In our 7 years' experience, there has been a gradual increase in the utilization of EVAR for infrarenal AAAs. At the same time, more infrarenal AAAs with hostile aortic necks requiring suprarenal aortic cross-clamping were encountered. In such instances, the retroperitoneal approach is safer, with less perioperative blood loss and shorter suprarenal cross-clamp time. This is likely attributed to better exposure of the suprarenal abdominal aorta, allowing a more secure proximal anastomosis.     

Revascularization of kidney allograft after renal artery occlusion secondary to angioplasty

Arterial thrombosis causing complete occlusion is a rare event in the natural history of a transplanted allograft; an incidence of 1.4% has been reported. This condition usually results from technical problems, hyperacute rejection, severe atherosclerosis, or injury to donor or recipient arteries. The treatment of choice is transplant nephrectomy. We report a case of renal artery occlusion after a therapeutic radiological procedure and subsequent salvaging of the graft. The case report shows that an aggressive surgical approach toward restoring circulation is worth the effort.