Comparison of hydraulic and hemolytic properties of different impeller designs of an implantable rotary blood pump by computational fluid dynamics

A mixed-flow blood pump for long-term applications has been developed at the Helmholtz-Institute in Aachen, Germany. Central features of this implantable pump are a centrally integrated motor, a blood-immersed mechanical bearing, magnetic coupling of the impeller, and a shrouded impeller, which allows a relatively wide clearance. The aim of the study was a numerical analysis of hydraulic and hemolytic properties of different impeller design configurations. In vitro testing and numerical simulation techniques (computational fluid dynamics [CFD]) were applied to achieve a comprehensive overview. Pressure-flow charts were experimentally measured in a mock loop in order to validate the CFD data. In vitro hemolysis tests were performed at the main operating point of each impeller design. General flow patterns, pressure-flow charts, secondary flow rates, torque, and axial forces on the impeller were calculated by means of CFD. Furthermore, based on streak line techniques, shear stress (stress loading), exposure times, and volume percentage with critical stress loading have been determined. Comparison of CFD data with pressure head measurements showed excel-lent agreement. Also, impressive trend conformity was observed between in-vitro hemolysis results and numerical data. Comparison of design variations yielded clear trends and results. Design C revealed the best hydraulic and hemolytic properties and was chosen as the final design for the mixed-flow rotary blood pump.     

Endoloop versus endostapler closure of the appendiceal stump in pediatric laparoscopic appendectomy

Background

There is little information available to inform choice of technique for appendiceal stump control in pediatric laparoscopic appendectomy (LA). We compared complications (stump leak, intra-abdominal abscess formation [IAA], surgical site infection [SSI]) in children undergoing LA for perforated (PA) and nonperforated appendicitis (NPA) by technique of appendiceal stump control.

Methods

All children who underwent LA for confirmed acute appendicitis between 2006 and 2009 were reviewed. Choice of stump control (endoloop [EL] or endostapler [ES]) was determined by surgeon preference. Interactions between stump closure techniques and other potential confounders (intra-abdominal drain, irrigation, different antibiotic regimens) were explored using a logistic regression model.

Results

Of 242 patients undergoing LA, 57 (23.6%) had PA. In the PA group the appendiceal stump was closed with EL in 47 (82.5%) patients, while in the NPA group EL was used in 161 (87%) patients. Among PA patients, IAA was more common in the ES than the EL group (5 of 10 [50%] v. 6 of 47 [12.7%]). There was no significant difference in rates of SSI. Among NPA patients, there were no differences in rates of IAA or SSI. There were no stump leaks in either group. Logistic regression analysis confirmed the predictive effect of ES use on IAA formation in PA (adjusted odds ratio 7.09; 95% confidence interval 1.08–46.13; p = 0.042).

Conclusion

Our data suggest that in most cases of PA, the appendiceal stump can be safely controlled with EL. Within the PA group, the higher rates of IAA seen in ES patients may be attributable to the quality of the appendiceal stump rather than the technique of closure.     

Safety, Complications, and Satisfaction of Patients Undergoing Submuscular Breast Augmentation via the Inframammary and Endoscopic Transaxillary Approach

Background Since its introduction, augmentation mammaplasty has gained widespread popularity, as demonstrated by the fact that an estimated 2 million women in the United States have received implants. During recent decades, several surgical approaches have evolved in terms of implant placement or site of access to the surgical plane. Debate has existed concerning the questionable superiority of a particular technique for achievement of optimal results. Thus, the inframammary approach, an established and widely accepted technique for breast augmentation, and endoscopically assisted transaxillary breast augmentation were retrospectively compared in terms of safety and aesthetic outcome, as measured, respectively, by the rate of postoperative complications and patient satisfaction. Methods This study analyzed 78 patients undergoing augmentation mammaplasty between 1997 and 2004. Only patients seeking primary augmentation mammaplasty solely for aesthetic reasons were included in the study. Previously performed breast surgery and simultaneously conducted ipsilateral mastopexy were among the exclusion criteria. Patient satisfaction was assessed using the client satisfaction questionnaire (CSQ-8) because of its easy applicability. Results The complication rate was low in both patient subsets, thus confirming the safety of the transaxillary approach, as compared with the more common submammary technique. However, a higher level of satisfaction was detected in the former patient group, indicating a more favorable aesthetic outcome with the transaxillary augmentation mammaplasty. Conclusion Endoscopically assisted transaxillary augmentation mammaplasty is a safe method with predictable results associated with a high level of patient satisfaction. If applied in the setting of appropriate indications, it is an excellent tool for use with patients who prefer to have an incision at a distant site.     

Optical coherence tomography for presurgical margin assessment of non‐melanoma skin cancer – a practical approach

In the clinical setting, optical coherence tomography (OCT) is applicable for the non‐invasive diagnosis of skin cancer and may in particular be used for margin definition prior to excision. In this regard, OCT may improve the success rate of removing tumor lesions more effectively, preventing repetitive excision, which may subsequently result in smaller excisions. In this study, we have aimed to evaluate the applicability of OCT for in vivo presurgical margin assessment of non‐melanocytic skin tumors (NMSC) and to describe the feasibility of different scanning techniques. A total number of 18 patients planned for excision of lesions suspicious of NMSC were included in this study. Based on OCT, we defined the specific tumor margins on 19 lesions preoperatively using different scanning modalities. Sixty‐one margin points and five complete tumor margins were analysed on 18 patients with a total of 19 lesions including 63% basal cell carcinoma (BCC) (n = 12), 16% (n = 3) squamous cell carcinoma (SCC) and 21% of other types of skin tumors (n = 4) were classified. In 84% of the cases (n = 16), the OCT‐defined lateral margins correctly indicated complete removal of the tumor. The surgical margins chosen by the surgeon never fell below the OCT‐defined margin. Regarding the techniques of marginal definition, punctual tumor border scan in the perpendicular direction, with an extension of free‐run scans for unsure cases can hardly be recommended. This study shows that suspected NMSC can effectively be confirmed, and furthermore, resection margin can be minimized under OCT control without reducing the rate of complete removal.     

Endoscopic resection of nasopharyngeal angiofibromas by combined transnasal and transoral routes

PURPOSE: To determine the role of endoscopic surgery in decreasing intraoperative bleeding, morbidity, and hospitalization period of juvenile nasopharyngeal angiofibroma resection and to describe combined endoscopic transnasal and transoral approaches. PATIENTS AND METHODS: Twelve cases of juvenile nasopharyngeal angiofibroma diagnosed by endoscopic examination, computed tomography, and angiography were selected for endoscopic resection. Tumor staging ranged from stage I(A) to II(B). Ten patients underwent preoperative selective arterial embolization, and in 1 case selective arterial ligation was used. In general, the tumors were approached endoscopically through nasal and oral cavities with 0 degrees and 30 degrees 4-mm telescopes without any incision and no packing at their termination. RESULTS: The patients were followed by endoscopy and computed tomography. There was a dramatic decrease in intraoperative bleeding and postoperative morbidity. No early postoperative complications were seen. Two recurrences were observed in 12 patients up to a mean follow-up of 15 months. CONCLUSIONS: Minimal bleeding, decreased morbidity, and shorter hospitalization period were the main reasons that prompted us to use endoscopic technique for the removal of juvenile nasopharyngeal angiofibroma. Adding transoral endoscopic approach to the transnasal endoscopic approach provides 2-sided exposure and appreciate access to angiofibroma.     

Comparison of salivary and plasma antioxidant levels in lichen planus patients and healthy subjects

J Oral Pathol Med (2012) 41 : 524–526 Introduction: Oral lichen planus (OLP) is a chronic, mucocutaneous, inflammatory disease. It has become more evident that the immune system plays a primary role in the development of this disease. The aim of the present study was to evaluate the total antioxidant status (TAS) of saliva and serum in patients with erosive OLP. Method and Materials: This study was designed as case‐control. In total, 48 patients with erosive OLP (34 women and 14 men) were enrolled as case group, and 44 self‐admitted healthy people (34 women and 10 men) were selected as control group. Measurement of total antioxidant status was carried out in saliva and plasma. t‐test was used for statistical analysis with significant level set at P < 0.05. Results: The mean ± SD of salivary TAS in case group was 0.98 ± 0.12, and in control group was 1.32 ± 0.18 mM, respectively, and there were significant differences between groups (P < 0.02). The mean ± SD of the plasma TAS in the case group and the control group was 1.24 ± 0.17 and 1.84 ± 0.34 mM, respectively. There were significant differences between two groups (P < 0.01). Conclusion: Our results showed that salivary and plasma levels of total antioxidant status in erosive OLP patients were lower than those in healthy subjects.     

Generalized Lupus Panniculitis and Antiphospholipid Syndrome in a Patient Without Complement Deficiency

Generalized chronic cutaneous lupus including lupus panniculitis in childhood is rare and usually occurs in the setting of genetic complement deficiencies. The association with antiphospholipid syndrome is even more rare. We report a 13-year-old girl with extensive lupus panniculitis since the age of 8 months and no evidence of complement deficiency. She recently developed antiphospholipid syndrome characterized by anticardiolipin antibodies and digital necrosis.