Long Term Outcomes Following Freestyle Stentless Aortic Bioprosthesis Implantation: An Australian Experience.

BACKGROUND: The Freestyle stentless bioprosthesis (FSB) has been demonstrated to be a durable prosthesis in the aortic position. We present data following Freestyle implantation for up to 10 years post-operatively and compare this with previously published results. METHODS: A retrospective cohort analysis of 237 patients following FSB implantation occurred at five Australian hospitals. Follow-up data included clinical and echocardiographic outcomes. RESULTS: The cohort was 81.4% male with age 63.2±13.0 years and was followed for a mean of 2.4±2.3 years (range 0-10.9 years, total 569 patient-years). The FSB was implanted as a full aortic root replacement in 87.8% patients. The 30-day all cause mortality was 4.2% (2.0% for elective surgery). Cumulative survival at one, five and 10 years was 91.7±1.9%, 82.8±3.8% and 56.5±10.5%, respectively. Freedom from re-intervention at one, five and 10 years was 99.5±0.5%, 91.6±3.7% and 72.3±10.5%, respectively. At latest echocardiographic review (mean 2.3±2.1 years post-operatively), 92.6% had trivial or no aortic regurgitation. Predictors of post-operative mortality included active endocarditis, acute aortic dissection and peripheral vascular disease. CONCLUSIONS: We report acceptable short and long term outcomes following FSB implantation in a cohort of comparatively younger patients with thoracic aortic disease. The durability of this bioprosthesis in the younger population remains to be confirmed.

Replacement of the aortic root with a composite valve-graft conduit: risk factor analysis in 246 consecutive patients.

BACKGROUND: Composite valve-graft (CVG) replacement of the aortic root is a well-studied and recognised treatment for various aortic root conditions, including valvular disease with associated aortopathy. There have been few previous studies of the procedure in large numbers in an Australian setting. METHOD: From January 2006 to June 2013, 246 successive patients underwent CVG root replacements at our institution. Mean age was 56.8 years, 85.4% were male, and 87 had evidence of bicuspid aortic valve. Indications for operation included ascending aortic aneurysm in 222 patients, annuloaortic ectasia in 67 patients, and aortic dissection in 38 patients. RESULTS: The overall unit 30-day mortality was 5.7%, including: elective 30-day mortality of 2.2%, and emergent 30-day mortality of 17.2%. Statistically significant multivariate predictors of 30-day mortality were: acute aortic dissection (OR=20.07), peripheral vascular disease (OR=11.17), new ventricular tachycardia (OR=30.17), re-operation for bleeding (OR=14.42), concomitant mitral stenosis (OR=68.30), and cerebrovascular accident (OR=144.85). CONCLUSIONS: Low postoperative mortality in our series matches closely with results from similar sized international studies, demonstrating that this procedure can be performed with low risk in centres with sufficient experience in the operative procedure.

Outcomes of aortic arch replacement surgery after previous cardiac surgery.

BACKGROUND: Aortic arch replacement is a potentially high-risk operation and in the re-operative setting has been found to be a risk factor for poor outcome, yet there is a dearth of published data specifically on this topic. The aim of the study was to review our unit's outcomes in this re-operative setting. METHOD: Data were collated for all patients who underwent aortic arch replacement surgery after previous cardiac surgery from January 1988 to November 2011. The patients were divided based primarily on elective versus non-elective and also early (≤2005) and late (≥2006) series. RESULTS: Twenty-seven eligible patients (22 male; median age: 53.0 years; elective: 14, non-elective: 13) were identified. There was a mean period of 14.5 years between the first operation and the subsequent aortic arch replacement. The overall 30-day mortality rate was 22.2% - 0% elective and 46.2% non-elective (P = 0.004). Overall permanent neurological dysfunction was 21.7% - 28.6% elective and 11.1% non-elective (P = 0.463). There were 11 early-series patients and 16 late-series patients. For early-series patients, 90.9% were non-elective versus 18.8% in the late-series patients. The 30-day mortality rate was 54.5% early series versus 0% late series. CONCLUSION: Aortic arch replacement is high risk in the re-operative setting. These risks are even greater for non-elective procedures. This highlights the need for aggressive first-time surgery to reduce re-operative procedures and good long-term follow-up programmes to allow elective procedures if required.

Outcomes of surgical aortic valve replacement in octogenarians.

BACKGROUND: In the era of TAVI, there has been renewed interest in the outcomes of conventional AVR for high-risk patients. This study evaluates the short- and long-term outcomes of AVR in octogenarians. METHODS: A retrospective review was performed of all 117 patients aged ≥ 80 years who underwent AVR, (isolated AVR (n = 60) or AVR+CABG (n = 57),) from August 2005 to February 2011 at Royal Prince Alfred Hospital and Strathfield Hospital. Univariate analysis was used to compare pre- and post-operative variables between younger and older subgroups (age 80-84, n = 82; age 85-89, n = 35 respectively). Long-term survival data was obtained from the National Death Index at the Australian Institute of Health and Welfare and survival curves were constructed using the Kaplan-Meier method. RESULTS: The median age was 83 years (interquartile range, 81-85 years), 46.2% were females, the median EuroSCORE was 10.89% (interquartile range, 8.20-16.45%) and 16.2% of patients had a EuroSCORE ≥ 20%. The difference between subgroups for history of stroke was significant (p = .042). Post-operative complications included pleural effusion (12.8%), new renal failure (4.3%) and respiratory failure (4.3%). The rate of major adverse events was extremely low, with no cases of stroke. The 30-day mortality rate was 3.4%. There was a significant difference between subgroups for 30-day mortality (p = .007). 38.9% of patients were discharged home, 11.5% were transferred to another hospital and 38.9% spent a period of time in a rehabilitation institution post discharge. In terms of long-term survival, the six-month, one-year and three-year survival was 95.6%, 87.6% and 58.4% respectively. CONCLUSIONS: Surgical AVR yields excellent short- and long-term outcomes for potentially high-risk, elderly patients.

International retrieval of adults on extracorporeal membrane oxygenation support.

A retrieval service was established in New South Wales to provide mobile extracorporeal membrane oxygenation support to patients with severe, acute cardiac or respiratory failure. This service has also retrieved four adult patients from Nouméa, New Caledonia to Sydney on extracorporeal membrane oxygenation support, which are the first international retrievals of this type from Australia. We discuss our experience with these patients, three of whom survived to hospital discharge. However, one patient referred from New Caledonia died before extracorporeal membrane oxygenation could be established.

Evolution in the techniques and outcomes of aortic arch surgery: a 22 year single centre experience.

BACKGROUND: Aortic arch replacement is a complicated and high risk procedure. There have been many advances over recent years. We review the changes in our unit's techniques and outcomes over the past 22 years. METHODS: Data were collated from databases and medical records for all patients who underwent aortic arch replacement surgery from January 1989 to December 2010. The patients were divided into two groups - Group A (1989-2005) and Group B (2006-2010). Data were analysed to compare early and late series patients' outcomes. Logistic regression was used to identify variables that predicted mortality. RESULTS: Seventy-five eligible patients (56 males; mean age: 57.5 years; Group A: 40, Group B 35) were identified. There were great changes in the technique and the methods of cerebral protection. The overall mortality rate was 30.7% - Group A: 50% and Group B: 8.6% (p<0.001). Overall permanent neurological dysfunction was 23.7% - Group A: 40% and Group B: 11.8% (p=0.012). Cardiovascular disease and circulatory arrest time were significant predictors of mortality. CONCLUSIONS: Increased experience and volume and advances in techniques over 22 years have resulted in major improvements in outcomes for patients having aortic arch replacement, allowing the procedure to be performed with greatly improved outcomes.

Interlaboratory trial on the analysis of alkylphenols, alkylphenol ethoxylates, and bisphenol A in water samples according to ISO/CD 18857-2.

ISO/CD 18857-2 (International Organization for Standardization, Geneva) describes a new international standard method for the determination of octylphenol, nonylphenol, their mono- and diethyoxylates, and bisphenol A in nonfiltered samples of drinking, ground, surface, and wastewater. The method is based on the extraction of the analytes from an acidified water sample by solid phase extraction, solvent elution, derivatization, and determination by gas chromatography with mass spectrometric detection. For validation of this method, 14 laboratories from 4 different countries in Europe and Canada participated in an interlaboratory trial to determine the performance characteristics of the method, which are intended for publication in the corresponding standard. The interlaboratory trial was evaluated according to ISO 5725-2 and included two duplicate nonfiltered water samples: surface water containing the target compounds in an analyte concentration range from 0.05 to 0.4 microg/L and wastewater containing the target compounds in a concentration ranged from 0.1 to 5 microg/L. The repeatability variation coefficients (within-laboratory precision) varied for all samples and compounds between 1.9 and 7.8%, showing a sufficiently high repeatability of the method. The reproducibility variation coefficients (between-laboratory precision) were found to vary within a satisfactory range of 10.0-29.5% for surface water and 10.8-22.5% for wastewater. The recoveries as a measure of accuracy varied from 98.0 to 144.1% for surface water and from 95.4 to 108.6% for wastewater. The determined concentrations of the samples compared well to the "true" values, thus showing very satisfactory accuracy of the method. In the chromatogram of the surface water sample, a high unresolved background made up of coextractable matrix compounds was apparent. It is conceivable that compounds from this background may be responsible for enhanced recoveries of 144.1% for 4-nonylphenol (mixture of isomers) and of 123.4% for 4-nonylphenol monoethoxylate (mixture of isomers) in the surface water samples. The isotope-marked standard compounds developed in this context proved to be reliable internal standards that allow a precise and accurate quantitation of all compounds specified in ISO/CD 18857-2. The results of the interlaboratory trial confirmed that the analytical method is robust and reliable and can be used as a standard method to analyze the target compounds in water samples.

Composite graft replacement of the aortic root after previous cardiac surgery: a 20-year experience.

BACKGROUND: An aging population and prolonged survival of patients after cardiac operations has meant that composite aortic root replacement after previous cardiac operation is being performed with increasing frequency. METHODS: From January 1979 to July 1999, 32 patients underwent "reoperative" composite replacement of the aortic root at our institution. Previous operations were 16 aortic valve replacement, 9 coronary artery bypass grafting, 5 repair aortic dissection, and 7 others. Indications for operation included ascending aortic aneurysm in 16 patients, ascending aortic dissections in 10 patients, and other in 6 patients. RESULTS: The unit elective mortality was 3 of 26 (11.5%). One surgeon's elective mortality was 1 of 22 (4.6%). The unit emergent mortality was 6 of 6 (100%). There has been one late death. Morbidity was low. CONCLUSIONS: Reoperative aortic root replacement is a technically demanding procedure, but expertise in the area achieves low elective mortality. Consideration should be given to aortic root replacement at the initial procedure. Close follow-up of postcardiac operation patients is necessary to proceed with elective aortic root replacement if indicated. Emergent presentation in the reoperative setting has a very poor prognosis.

Video-assisted thoracoscopy.

Recent advances in video-imaging and minimally invasive surgical instrumentation have expanded the role of thoracoscopy in the diagnosis and treatment of intrathoracic conditions. This prospective study describes the use of video-assisted thoracoscopy (VAT) in 100 consecutive patients. There were 70 males and 30 females with a mean age of 54.6. They underwent 103 VAT procedures with 41 thoracoscopic biopsies of lung, pleural, chest wall and mediastinal abnormalities, 32 for treatment of recurrent or persistent pneumothorax, 18 for thoracoscopic assessment of pulmonary and pleural tumours and 12 for thoracoscopic resection of peripheral lung lesions, chest wall, mediastinal and pleural tumours. Eighty-one patients had VAT procedures alone while the remaining 19 had VAT proceeding to thoracotomy. The mean operating time for VAT alone was 51 min (range 30-135 min). There were no operative deaths. There were 8 significant complications from which patients recovered fully. Patients who underwent VAT alone were shown to have earlier postoperative mobilization, reduction in parenteral analgesic requirement and reduced length of hospital stay compared to patients undergoing additional thoracotomy. A telephone survey of patients on returning home showed that patients undergoing VAT alone returned to full activity earlier than those who had thoracotomy (mean 9.0 vs mean 19.4 days). This study confirms that VAT is a safe and effective procedure in the management of pulmonary, mediastinal and pleural disease and the treatment of persistent and recurrent pneumothorax. Its role in the resection of pulmonary malignancy remains to be defined.

[Distribution pattern of chemicals in surface waters as a reflexion of entry pattern--volatile halogenated hydrocarbons]. / Stoffmusterverteilungen in Oberflächengewässern als Reflexion von Eintragsmustern--Leichtflüchtige halogenierte Kohlenwasserstoffe.

The part gives some data about various light volatile halogenated hydrocarbons in surface waters of the industrialized city and its surroundings--the halogenated forms, chloroform and bromoform and the most used solvents trichloroethylene, tetrachloroethylene, tetrachloromethane and 1,1,2,2-tetrachloroethane. 80% of the concentrations of chloroform, tri- and tetrachloroethylene were in the range of less than 1 microgram l-1, 90% of bromoform, tetrachloromethane and 1,1,2,2-tetrachloroethane were found to amount less than 0.1 microgram l-1. With the help of the differential-diagnostic assessment method described in the first part we tried to evaluate the data for tetrachloromethane. The highest values were obtained for almost all sampling points in April--a possible cause may be the use of this solvent for cleaning and repairing procedures with sport boats (although tetrachloromethane has been prohibited for such uses for some years there may be some remainders which were used for these purposes).

[Distribution pattern of chemicals in surface waters as a reflexion of entry pattern--heavy metals]. / Stoffmusterverteilung in Oberflächengewässern als Reflexion von Eintragsmustern--Schwermetalle.

The concentrations of the heavy metals lead, cadmium and mercury were measured in surface water samples of an industrialized city and its surroundings. All but one value of Cd (particular) were less than 0.5 microgram l-1, 30% of the lead (particular) values were less than 0.5 microgram l-1, 70% 0.5 ... 10 micrograms l-1, 86% of the total mercury less than 0.1 and 14% 0.1 ... 0.5 microgram l-1. By applying the differential-diagnostic assessment method it could be found that the highest values were found in the vicinity of a metal-using factory. On a sampling point near such an enterprise the part of particularly bound lead was very low, that means a recent input, whereas on another sampling point with a high total lead level 95% were particularly bound which refers to a continuous input.

Human cranial bone structure and the healing of cranial bone grafts: a study using backscattered electron imaging and confocal microscopy.

This study explored the microstructure of human cranial bone at different ages, and the survival, remodelling and modelling of cranial bone grafts. A combination of reflection and fluorescence confocal optical microscopy and scanning electron microscopy in the backscattered electron imaging mode was employed to examine highly polished block faces of plastic-embedded bone fragments as harvested for grafting, or recovered after a period in situ as a graft. The methods enabled remarkably detailed information on bone content, maturation and turnover to be gleaned from tiny scraps of bone. Microfractures in the harvested bone were repaired at the graft site, with welding of old and new bone indicating revascularization. Human cranial bone grafts successfully stimulated bone cell differentiation, supported new bone formation on resorbed and unresorbed surfaces, and underwent bone turnover. The type and organization of new bone reflected the growth rate and maturation of the graft rather than the age of the patient.

Acute myocardial ischaemia and cardiogenic shock after percutaneous transluminal coronary angioplasty; risk factors for and results of emergency coronary bypass.

Between 1 September, 1980 and 1 January, 1989, 4142 patients underwent percutaneous transluminal coronary angioplasty (PTCA). We retrospectively studied the 155 [3.7%; 119 males, mean age 53.4 years, (range 33-78 years) and 36 females, mean age 59.6 years (range 40-74 years)] who required urgent coronary artery bypass grafting (CABG) (Group I) and a select control group of 155 patients, in whom PTCA was performed without complications (Group II). Before PTCA, 14 Group I and 42 Group II patients had angina Class II, and 78 Group I and 49 Group II patients had angina class IV (chi 2-test, P less than 0.05). There were 445 complications in the 155 group I patients: 303 (68%) early (during PTCA) and 141 (32%) late (within 24 h). On arrival in the operating room 126 patients were stable; five were in cardiac arrest and 19 in cardiogenic shock (AS-group; 24 patients). In the AS-group and control group, respectively, angina Class II occurred in 2/24 (8.3%) and 42/155 (27.1%) patients, angina Class IV in 14/24 (58.3%) and 49/155 (31.6%) (P less than 0.05), single-vessel disease in 8/24 (33.3%) and 85/155 (54.8%), triple-vessel disease in 7/24 (29.2%) and 23/155 (14.9%) (P less than 0.05); elective PTCA in 11/24 (45.8%) and 92/155 (59.4%), urgent PTCA in 12/24 (50%) and 48/155 (30.9%) (P less than 0.05), PTCA of the left anterior descending artery (LAD) in 18/24 (75%) and 86/166 (51.8%), PTCA of the right coronary artery in 2/24 (8.3%) and 47/166 (28.3%) (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Björk-Shiley strut fracture and disc escape: literature review and a method of disc retrieval.

Embolization of a prosthetic valve poppet is a rare but life-threatening event. It was reported sporadically before the introduction of the Björk-Shiley 70-degree convexoconcave prosthesis in 1980. Since that time, there have been a large number of reported mechanical failures with disc escape. The rate for the 29-mm to 33-mm mitral valves is estimated as 5.2%. In 29 of 35 patients (including the 2 presented here) in whom the site of disc lodgment could be determined, the disc was in the descending or abdominal aorta. Fifteen of these patients died. Six survivors had the disc removed at the same operation and 6 at a later operation. In 2 patients, the disc was not removed. In 2 patients in whom the disc was not removed initially, it was thought to contribute to postoperative complications. Two more cases of structural failure of the Björk-Shiley convexoconcave prosthesis are presented. A transpericardial approach to the descending aorta on bypass is described. It allows easy removal of the disc and eliminates the need for a second operation.

Projection geometry and stress-reduction techniques in craniofacial surgery.

Since 1981, we have been able to modify the mathematical patterns of projection geometry to reshape the skull in craniofacial surgery. Unlike burring, morcellization, rotation, and plate switching, this technique actually changes the shape of individual sections of the skull by changing their radius of curvature. The technique is an adaptation of the principles used by engineers to build complex structures such as ships' hulls, airfoils, and domes. The result is a rigid form of the desired shape that becomes permanent with healing. This has several advantages: 1. An increase in the level of safety of craniofacial procedures for remodeling the skull. This is so because there is no need to dissect normal areas as in the standard plate-switching techniques. 2. Decreased operating room time. 3. An increased range of surgical manipulations. No longer is the surgeon limited to the shape of the material present. 4. Relief of edge pressure on the frontal lobes during scalp closure. 5. Creation of a solid bony form over which the pericranial scalp flap can be draped to form new layers of bone.

The harvesting of cranial bone grafts: a guided osteotome.

A technique for in situ harvesting of the outer table of the skull using a "guided" osteotome is presented. While guards have been placed to control the depth of the blade, additional steps are advised to ensure the highest level of safety in clinical use: Before harvesting the graft, a full set of anteroposterior and lateral x-rays should be examined to determine which areas of the skull are thin and should be avoided. All areas with cranial sutures should be avoided because here the dura is more firmly attached to the inner table making perforation more dangerous. Bone should not be harvested under the hairless forehead region because this results in a visible depression. The surgeon should use the guards as guides to visually monitor the depth of the blade. The surgeon should not attempt the procedure without having a set of three different depths (1 mm, 2 mm, and 3 mm) available. Different skulls have different thicknesses of the outer table, and the technique loses the advantage of safety if an inappropriate depth is used.