15 Years in surgical management of pulmonary hydatidosis.

OBJECTIVES: Echinococcosis remains an endemic surgical problem in countries where sheep and cattle raising is carried out, particularly in many Mediterranean countries. This study aims to evaluate the management of different presentations of pulmonary hydatidosis and their outcome over 15 years. DESIGN: Retrospective study.Setting: Thoracic surgical department, Chest Diseases Hospital, Kuwait. PATIENTS: Sixty patients operated upon for hydatid disease were evaluated pre- and post- operatively; 35 males, 25 females with a mean age of 28.4 years. Most patients were investigated by laboratory, serological and radiological studies. Different surgical techniques were used to remove the hydatid cyst from the lung. RESULTS: The most common presenting symptoms were cough (41 patients), and 12 patients were asymptomatic. Chest X-ray showed a rounded shadow in 42 patients; 19 cases were of vigorous size >10 cm. Thoracotomy was done in 57 patients; two chest wall cases were managed by minimal skin incision and enucleation, one hydatid cyst of the heart was approached through a median sternotomy. The mean hospital stay was 9 days. Postoperative complications occurred in 9 patients; prolonged air leak in 4 patients, pleural effusion in 3, pneumothorax, and wound infection in one patient each. One patient (65 years old) died on the 6th post-operative day most probably from pulmonary embolism. In a follow-up period of 2-15 years, 4 recurrences have been noted. CONCLUSION: Surgical excision of pulmonary hydatidosis with maximum preservation of the lung parenchyma is the main stay of treatment.     

Development of a novel pulsatile bioreactor for tissue culture

The construction of tissue-engineered parts such as heart valves and arteries requires more than just the seeding of cells onto a biocompatible/biodegradable polymeric scaffold. It is essential that the functionality and mechanical integrity of the cell-seeded scaffold be investigated in vitro prior to in vivo implantation. The correct hemodynamic conditioning would lead to the development of tissues with enhanced mechanical strength and cell viability. Therefore, a bioreactor that can simulate physiological conditions would play an important role in the preparation of tissue-engineered constructs. In this article, we present and discuss the design concepts and criteria, as well as the development, of a multifunctional bioreactor for tissue culture in vitro. The system developed is compact and easily housed in an incubator to maintain sterility of the construct. Moreover, the proposed bioreactor, in addition to mimicking in vivo conditions, is highly flexible, allowing different types of constructs to be exposed to various physiological flow conditions. Initial verification of the hemodynamic parameters using Laser doppler anemometry indicated that the bioreactor performed well and produced the correct physiological conditions.     

Artificial aortic valves: an overview

This review discusses strategies that may address some of the limitations associated with replacing diseased or dysfunctional aortic valves with mechanical or tissue valves. These limitations range from structural failure and thromboembolic complications associated with mechanical valves to a limited durability and calcification with tissue valves. In pediatric patients there is an issue with the inability of substitutes to grow with the recipient. The emerging science of tissue engineering potentially provides an attractive alternative by creating viable tissue structures based on a resorbable scaffold. Morphometrically precise, biodegradable polymer scaffolds may be fabricated from data obtained from scans of natural valves by rapid prototyping technologies such as fused deposition modelling. The scaffold provides a mechanical profile until seeded cells produce their own extra cellular matrix. The microstructure of the forming tissue may be aligned into predetermined spatial orientations via fluid transduction in a bioreactor. Although there are many technical obstacles that must be overcome before tissue engineered heart valves are introduced into routine surgical practice these valves have the potential to overcome many of the shortcomings of current heart valve substitutes.     

Flow characteristics past jellyfish and St. Vincent valves in the aortic position under physiological pulsatile flow conditions

Thrombus formation and hemolysis have been linked to the dynamic flow characteristics of heart valve prostheses. To enhance our understanding of the flow characteristics past the aortic position of a Jellyfish (JF) valve in the left ventricle, in vitro laser Doppler anemometry (LDA) measurements were carried out under physiological pulsatile flow conditions. The hemodynamic performance of the JF valve was then compared with that of the St. Vincent (SV) valve. The comparison was given in terms of mean systolic pressure drop, back flow energy losses, flow velocity, and shear stresses at various locations downstream of both valves and at cardiac outputs of 3.5 L/min, 4.5 L/min, and 6.5 L/min respectively. The results indicated that both valves created disturbed flow fields with elevated levels of turbulent shear stress as well as higher levels of turbulence in the immediate vicinity of the valve and up to 1 diameter of the pipe (D) downstream of the valve. At a location further downstream, the JF valve showed better flow characteristics than the SV in terms of velocity profiles and turbulent shear stresses. The closure volume of the SV valve was found to be 2.5 times higher than that of the JF valve. Moreover, the total back flow losses and mean systolic pressure drop also were found to be higher in the SV than the JF valve.     

Radiological impact assessment to the environment due to waste from disposal of porcelain

The present study aimed to assess the radiological parameters from gamma rays due to the uncontrolled disposal of porcelain waste to the environment. Qualitative and quantitative identification of radionuclides in the investigated samples was carried out by means of a high-purity germanium (HPGe) detector. The average activity concentrations of the local porcelain samples were measured as 208.28?Bq/kg for ²²⁶Ra, 125.73?Bq/kg for ²³⁸U, 84.94?Bq/kg for ²³²Th and 1033.61?Bq/kg for ⁴⁰K, respectively. The imported samples had an average activity of 240.57?Bq/kg for ²²⁶Ra, 135.56?Bq/kg for ²³⁸U, 115.74?Bq/kg for ²³²Th and 1312.49?Bq/kg for ⁴⁰K, respectively. Radiological parameters and the radium equivalent Ra_eq for the investigated samples were calculated. The external and internal hazard indices, representative level index (I_γ), alpha index (I_α), and the exemption level (I_x), were estimated to be higher than the recommended value (unity), while the average activity concentrations for the studied samples were higher than recommended levels. In conclusion, we are concerned that disposal of porcelain in the environment might be a significant hazard.     

Adding a custom made pressure release valve during air enema for intussusception: A new technique

Background:

Non-surgical reduction remains the first line treatment of choice for intussusception. The major complication of air enema reduction is bowel perforation. The authors developed a custom made pressure release valve to be added to portable insufflation devices, delivering air at pressures accepted as safe for effective reduction of intussusception in children under fluoroscopic guidance. The aim of this study was to develop a custom made pressure release valve that is suitable for the insufflation devices used for air enema reduction of intussusception and to put this valve into regular clinical practice.

Materials and Methods:

An adjustable, custom made pressure release valve was assembled by the authors using readily available components. The valve was coupled to a simple air enema insufflation device. The device was used for the trial of reduction of intussusception in a prospective study that included 132 patients.

Results:

The success rate for air enema reduction with the new device was 88.2%. The mean pressure required to achieve complete reduction was 100 mmHg. The insufflation pressure never exceeded the preset value (120 mmHg). Of the successful cases, 58.3% were reduced from the first attempt while 36.1% required a second insufflation. Only 5.55% required a third insufflation to complete the reduction. In cases with unsuccessful pneumatic reduction attempt (18.1%), surgical treatment was required. Surgery ranged from simple reduction to resection with a primary end to end anastomosis. No complications from air enema were recorded.

Conclusions:

The authors recommend adding pressure release valves to ensure safety by avoiding pressure overshoot during the procedure.Key words: Air enema, intussusception, pneumatic, pressure release, reduction, safety, valve     

Superior outcome of strut allograft-augmented plate fixation for the treatment of periprosthetic fractures around a stable femoral stem

Purpose

This study was designed to compare the outcome of two surgical approaches for treating femoral periprosthetic fractures around a stable femoral stem. The hypothesis was that plate fixation alone might be associated with a higher complication rate due to insufficient mechanical stability. We also considered that the addition of a strut allograft would contribute to fracture healing by means of osteoconduction.

Methods

We retrospectively assessed the outcome of 21 patients who sustained periprosthetic fractures around a total hip replacement system (Vancouver type B1 and type C fractures) and who were treated in our department (January 2006 and August 2011) either by plate fixation alone or by plate fixation and a strut allograft. The mean postoperative follow-up was 23 months (range 9–69 months). Eleven patients were treated by plate fixation alone (Plate Group), and 10 patients were treated by plate fixation and a deep frozen cortical strut allograft (AG Group). Functional outcome was rated by the Harris Hip scoring system. Postoperative radiographs were assessed for evidence of fracture union. Surgical failure was defined as any complication requiring surgical revision.

Results

The 21 patients included 17 females and 4 males. The average age was 79 years (range, 73–88) for the Plate Group and 82 years (range, 53–94) for the AG Group, and the average time to fracture union was 12 weeks (range, 2.5–6 months) and 12.95 weeks (range, 1.5–3) respectively. The overall failure rate was significantly higher in the Plate Group: 5 of them required revision surgery compared to none in the AG Group (p = 0.014).

Conclusion

The results of this analysis indicate that a strut allograft augmentation approach to Vancouver type B1 and type C periprosthetic fractures results in a better outcome than plate fixation alone by apparently adding mechanical stability and enhancing the biological healing process.     

The Effect of Type of Femoral Component Fixation on Mortality and Morbidity after Hip Hemiarthroplasty: A Systematic Review and Meta-Analysis

HSS Journal ® - Hip hemiarthroplasty is a well-established treatment of displaced femoral neck fracture, although debate exists over whether cemented or uncemented fixation is superior....