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Biomedical subjects

M F O'Brien

Publications and source records attributed to M F O'Brien.

At least 19 recordsLinked to original sources
PubMed2006

Testicular vasculitis mimicking a testicular neoplasm.

Vasculitis of the testis generally presents as a manifestation of systemic vasculitis which is well documented. In isolation, it has only been described on few occasions previously, and hitherto it has been in the young. It often mimics a neoplasm of the testis resulting in radical orchidectomy, only for it to be diagnosed when the specimen is examined under the microscope. In our case, an elderly man presented to us with a presumed testicular neoplasm, however, despite strong clinical and radiological suspicion a testicular vasculitis in isolation was revealed. Following our experience, we performed a literature review and examined all of the cases of testicular vasculitis reported so far and present our findings. We report the general clinical presentation, methods of investigation and subsequent management. This is the first time it has been described in the elderly population.

Aged↗
PubMed2004

Interleukin-2, interferon-alpha and 5-fluorouracil immunotherapy for metastatic renal cell carcinoma: the all Ireland experience.

OBJECTIVE: To analyse the long-term efficacy of combined interferon-alpha (IFN-alpha) and interleukin-2 (IL-2) subcutaneously, with 5-fluorouracil (5-FU) intravenously in a general multicentre setting, as treatment for metastatic renal cell carcinoma (RCC). METHODS: Fifty-nine patients with metastatic RCC were scheduled to receive an 8-week cycle of immunotherapy. Karnofsky score ranged from 70 to 100 (median 90). Thirty-one patients at presentation had metastases of which 14 underwent nephrectomy. Metastases occurred in multiple organs (lung 74%, mediastinal lymphadenopathy 22%, bone 21%). Therapeutic response and survival were analysed. RESULTS: Nine patients died from disease progression prior to completion of one full cycle. Six cases (10%) have stable disease at a follow-up of 51 months (range 20-88 months). Currently 11 patients (19%) are alive at a mean follow-up of 45 months (range 18-88 months). Forty-eight patients (81%) died of their disease at a mean follow-up of 10 months (range 0.5-46 months). Survival rate at 1 year was 53%, at 2 years 21%, at 3 years 16% and at 5 years 5%. Overall median survival is 10 months. CONCLUSION: IL-2 and IFN-alpha with 5-FU based immunotherapy achieve durable survival rates at 3 years in a minority of patients. Addition of 5-FU does not increase survival in our group. This study population is very different to other reported series. However it reflects better the entire population with metastatic RCC though results are subsequently poorer. Identifying patients that will respond is paramount.

Adult↗
PubMed2001

Comparison of epsilon aminocaproic acid and low-dose aprotinin in cardiopulmonary bypass: efficiency, safety and cost.

BACKGROUND: In this study we compared the clinical efficiency, safety, and economic benefit of low-dose aprotinin with epsilon aminocaproic acid (EACA) in reducing bleeding after cardiopulmonary bypass operation. METHODS: In a double-blind, randomized study, 100 patients received low-dose aprotinin (2 x 10(6) kallikrein inhibitor units) or EACA (20 g). The surgical procedure was single- or double-valve replacement with or without coronary artery bypass grafts. RESULTS: Mediastinal chest drainage and transfusion requirements with both therapies were similar. There were no urgent reoperations to secure hemostasis in either group. Similar levels of D-dimer with both therapies indicate a similar inhibition of fibrinolysis. Release of troponin I was less in the low-dose aprotinin group 1 and 4 hours after bypass, although electrocardiographic measurements did not reflect this difference. Levels of S-100beta and neuron-specific enolase were similar with both therapies, confirming that there was no difference in the occurrence of any adverse neurologic events in either group. CONCLUSIONS: Low-dose aprotinin and EACA showed similar effects on the reduction of intraoperative and postoperative bleeding. The lower cost of EACA with no change in safety outcome suggests it is the preferred treatment.

Aminocaproic Acid↗
PubMed2001

Postoperatively administered aprotinin or epsilon aminocaproic acid after cardiopulmonary bypass has limited benefit.

BACKGROUND: Intraoperative antifibrinolytic treatment with aprotinin and epsilon aminocaproic acid (EACA) has been shown to be effective prophylaxis in the reduction of excessive bleeding after cardiopulmonary bypass operations. This study investigated the effectiveness of both drugs when used as a postoperative treatment of patients showing early signs of increased bleeding. METHODS: In a double-blind, randomized study, 69 patients with chest drainage of 100 mL or more 1 hour after bypass were treated with aprotinin, EACA, or placebo. RESULTS: In the first 24 hours postoperatively, neither drug significantly reduced chest drainage or blood transfusion requirements compared with placebo. Median (interquartile) cumulative chest drainage volumes for the first 24 hours postoperatively for the aprotinin, EACA, and placebo groups were 525 (340, 750), 575 (450, 762), and 650 (550, 800) mL, respectively. Among the study patients, 4 undergoing valve operation and treated with aprotinin showed a trend toward less bleeding during the first 12 hours postoperatively compared with 5 valve operation patients who received placebo (p = 0.06). Among all patients, the treatment with aprotinin or EACA failed to reduce levels of D-dimer compared with placebo after treatment, indicating that fibrinolysis was not significantly inhibited. CONCLUSIONS: Aprotinin or EACA administered in the early postoperative period was ineffective in reducing postoperative bleeding with the exception of a small group of patients having valve operations in whom aprotinin treatment may have shown some benefit.

Aged↗
PubMed2001

The homograft aortic valve: a 29-year, 99.3% follow up of 1,022 valve replacements.

BACKGROUND AND AIM OF THE STUDY: The study aim was to elucidate the advantages and limitations of the homograft aortic valve for aortic valve replacement over a 29-year period. METHODS: Between December 1969 and December 1998, 1,022 patients (males 65%; median age 49 years; range: 1-80 years) received either a subcoronary (n = 635), an intraluminal cylinder (n = 35), or a full root replacement (n = 352). There was a unique result of a 99.3% complete follow up at the end of this 29-year experience. Between 1969 and 1975, homografts were antibiotic-sterilized and 4 degrees C stored (124 grafts); thereafter, all homografts were cryopreserved under a rigid protocol with only minor variations over the subsequent 23 years. Concomitant surgery (25%) was primarily coronary artery bypass grafting (CABG; n = 110) and mitral valve surgery (n = 55). The most common risk factor was acute (active) endocarditis (n = 92; 9%), and patients were in NYHA class II (n = 515), III (n = 256), IV (n = 112) or V (n = 7). RESULTS: The 30-day/hospital mortality was 3% overall, falling to 1.13 +/- 1.0% for the 352 homograft root replacements. Actuarial late survival at 25 years of the total cohort was 19 +/- 7%. Early endocarditis occurred in two of the 1,022 patient cohort, and freedom from late infection (34 patients) actuarially at 20 years was 89%. One-third of these patients were medically cured of their endocarditis. Preservation methods (4 degrees C or cryopreservation) and implantation techniques displayed no difference in the overall actuarial 20-year incidence of late survival endocarditis, thromboembolism or structural degeneration requiring operation. Thromboembolism occurred in 55 patients (35 permanent, 20 transient) with an actuarial 15-year freedom in the 861 patients having aortic valve replacement +/- CABG surgery of 92% and in the 105 patients having additional mitral valve surgery of 75% (p = 0.000). Freedom from reoperation from all causes was 50% at 20 years and was independent of valve preservation. Freedom from reoperation for structural deterioration was very patient age-dependent. For all cryopreserved valves, at 15 years, the freedom was 47% (0-20-year-old patients at operation), 85% (21-40 years), 81% (41-60 years) and 94% (>60 years). Root replacement versus subcoronary implantation reduced the technical causes for reoperation and re-replacement (p = 0.0098). CONCLUSION: This largest, longest and most complete follow up demonstrates the excellent advantages of the homograft aortic valve for the treatment of acute endocarditis and for use in the 20+ year-old patient. However, young patients (< or = 20 years) experienced only a 47% freedom from reoperation from structural degeneration at 10 years such that alternative valve devices are indicated in this age group. The overall position of the homograft in relationship to other devices is presented.

Adolescent↗
PubMed2001

Allograft aortic root replacement in 418 patients over a span of 15 years: 1985 to 2000.

Allograft aortic root replacement for primary aortic valve or ascending aortic root pathology is the favored method of technical implantation. Results in 418 patients over 15 years demonstrate exceedingly low early mortality (<1%), complete eradication of preoperative endocarditis but poor long-term durability in the young age group of 20 years or less.

Actuarial Analysis↗
PubMed2001

Longevity of the Marshall-Marchetti-Krantz procedure.

BACKGROUND AND AIMS: The Marshall-Marchetti-Krantz procedure (MMK) is a vesico-urethral suspension, for the correction of urethral hypermobility in women with stress urinary incontinence. This study aims to describe the long-term outcome of the procedure. MATERIAL AND METHODS: 40 women with stress incontinence underwent the MMK. All operations were performed by one surgeon. Analysis of patients' notes yielded the early continence rate and perioperative morbidity. Long-term outcome was measured by means of a postal questionnaire with telephone contact to ensure maximum uptake. RESULTS: The immediate continence rate was 82%. Continence rates at up to 22 years follow-up (mean 8.5 years) is 61%. All failures occurred within 2 years of the operation. CONCLUSION: Patients still continent two years after the MMK will maintain continence in the long-term.

Adult↗
PubMed2000

Pedicle morphology in thoracic adolescent idiopathic scoliosis: is pedicle fixation an anatomically viable technique?

STUDY DESIGN: A radiographic study of thoracic pedicle anatomy in a group of adolescent idiopathic scoliosis (AIS) patients. OBJECTIVE: To investigate the anatomic constraints of the thoracic pedicles and determine whether the local anatomy would routinely allow pedicle screw insertion at every level. SUMMARY OF BACKGROUND DATA: In spite of the clinical successes reported with limited thoracic pedicle screw-rod constructs for thoracic AIS, controversy exists as to the safety of this technique. MATERIAL AND METHODS: Twenty-nine patients with right thoracic AIS underwent preoperative thoracic CT scans and plain radiographs. Anatomic parameters were measured from T1 to T12. RESULTS: Information on 512 pedicles was obtained. The transverse width of the pedicles from T1 through T12 ranged from 4.6-8.25 mm. The medial pedicle to lateral rib wall transverse width from T1 through T2 ranged from 12.6 to 17.9 mm. Measured dimensions from the CT scans showed the actual pedicle width to be 1-2 mm larger than would have been predicted from the plain radiographs. Age, Risser grade, curve magnitude, and the amount of segmental axial rotation did not correlate with the morphology or size of the thoracic pedicles investigated. In no case would pedicle morphology have precluded the passage of a pedicle screw. CONCLUSION: Based on the data identified in this group of adolescent patients, it is reasonable to consider pedicle screw insertion at most levels and pedicle-rib fixation at all levels of the thoracic spine during the treatment of thoracic AIS.

Adolescent↗
PubMed2000

Late complications of tissue glues in aortic surgery.

BACKGROUND: Tissue glues are used in cardiothoracic surgery as an adjunct to operative procedures where tissues are frail, as in aortic dissection, or where added hemostasis is required. This study was undertaken to review the use of tissue glue in our institution over a 5.5-year period. The aim of the study was to identify any potentially glue-related complications. METHODS: A review of tissue glue use for the period from January 1993 to September 1998 was performed and pre-, intra-, and postoperative parameters were collected. After some unusual surgical findings, of special interest was a range of pathology found at late reoperation. RESULTS: A total of 67 cases of tissue glue use were identified, with the majority of operations for type A dissection (76%). There were two intraoperative deaths. Twenty-seven of 65 patients (41%) required 29 further open chest operations; of these, 17 were for acute problems of bleeding or tamponade. Twelve patients (18%) underwent late reoperations months to years later. Nine of these patients, concentrated in two operative groups (7 patients with aortic valve resuspension and 2 patients who had undergone "switch" operations for transposition of great vessels), displayed complications related to the application of gelatin-resorcinol-formaldehyde (GRF) tissue glue. CONCLUSIONS: Indications for tissue glues in cardiothoracic surgery must be carefully considered. We have reviewed our use of some tissue glues in acute type A aortic dissections and in pediatric cardiac patients and have discontinued the use of GRF glues because of unsatisfactory long-term complications.

Aortic Dissection↗
PubMed2000

Transpecies heart valve transplant: advanced studies of a bioengineered xeno-autograft.

BACKGROUND: Tissue engineering approaches utilizing biomechanically suitable cell-conductive matrixes should extend xenograft heart valve performance, durability, and growth potential to an extent presently attained only by the pulmonary autograft. To test this hypothesis, we developed an acellular, unfixed porcine aortic valve-based construct. The performance of this valve has been evaluated in vitro under simulated aortic conditions, as a pulmonary valve replacement in sheep, and in aortic and pulmonary valve replacement in humans. METHODS: SynerGraft porcine heart valves (CryoLife Inc, Kennesaw, GA) were constructed from porcine noncoronary aortic valve cusp units consisting of aorta, noncoronary aortic leaflet, and attached anterior mitral leaflet (AML). After treatment to remove all histologically demonstrable leaflet cells and substantially reduce porcine cell-related immunoreactivity, three valve cusps were matched and sewn to form a symmetrical root utilizing the AML remnants as the inflow conduit. SynerGraft valves were evaluated by in vitro hydrodynamics, and by in vivo implants in the right ventricular outflow tract of weanling sheep for up to 336 days. Cryopreserved allograft valves served as control valves in both in vitro and in vivo evaluations. Valves were also implanted as aortic valve replacements in humans. RESULTS: In vitro pulsatile flow testing of the SynerGraft porcine valves demonstrated excellent valve function with large effective orifice areas and low gradients equivalent to a normal human aortic valve. Implants in sheep right ventricular outflow tracts showed stable leaflets with up to 80% of matrix recellularization with host fibroblasts and/or myofibroblasts, and with no leaflet calcification over 150 days, and minimal deposition at 336 days. Echocardiography studies showed normal hemodynamic performance during the implantation period. The human implants have proven functional for over 9 months. CONCLUSIONS: A unique heart valve construct has been engineered to achieve the equivalent of an autograft. Short-term durability of these novel implants demonstrates for the first time the possibility of an engineered autograft.

Animals↗
PubMed2000

The stentless xenograft aortic valve: the wheel turns around.

BACKGROUND: A brief overview of the historical pathways of both stented and stentless porcine xenografts is presented in order to understand the return to and continuing clinical use of stentless devices. In addition, 7-11 years of durability with various models of stentless porcine valves has now accumulated and is beginning to be of relevance in determining the future place of this xenograft. Stentlessness and anticalcium agents, coupled with the poor results of stented xenografts in certain patient groups, have led to a resurgence of the clinical use of stentless xenograft valves for aortic valve replacement. An overview of the present state and future of stentless valves is given. METHODS: At both The Prince Charles Hospital and St Andrew's War Memorial Hospital, Queensland, Australia, 307 patients have received the Model 300 CryoLife-O'Brien stentless composite aortic xenograft from December 1992 to February 2000. Associated procedures were required in 56% of patients (mostly coronary artery bypass, mean 2.4 grafts, in 144 patients (47%) and left ventricular myomectomy in 34 patients (11%)). RESULTS: The hospital mortality (four early deaths) has been 1.3 +/- 1% (CL 95%) and the follow-up 100% for this analysis. The mean patient age was 73 years (range 57-89 years with 16% being 80 years and over). Morbid events have included six perivalvar leaks: four trivial and identified only on echo Doppler (no clinical murmurs) and two patients requiring reoperation at 10 days and 12 weeks with simple successful repair verified on subsequent echocardiograms. Of the 307 patients over the 7 year period, three valves only have been explanted, two for endocarditis at 1.5 and 3.5 years and one for possible technically induced structural failure at 15 months (probable needle damage). With this exception, there has been as yet no other intrinsic leaflet failure. Four early thromboembolic events (4 days-5 weeks) in patients with atrial fibrillation (no anticoagulants used postoperatively with the first 80 patients) constituted the important early morbid events. Late mortality of this elderly patient cohort has occurred in 27 patients over 7 years of maximum follow-up. One death (endocarditis) has been valve related at 5 years. Serial echocardiography (some 700 echoes in the study of this valve) has demonstrated a mean gradient of 7-9 mmHg with a very low incidence of trivial incompetence (96%) on Doppler examination with implant valve sizes ranging from 21 to 29 mm. One patient had significant regurgitation requiring reoperation. There has been no progression of either incompetence or stenosis of the remaining patients in this follow-up, now into the eighth postoperative year. CONCLUSION: The early and intermediate results appear excellent in this elderly patient cohort. Nevertheless, important surveillance is obviously required to determine the durability at 10-12 years, a crucial time when stented porcine xenografts began to show an obvious failure rate from structural deterioration, in the middle and elderly aged patient cohort. An attempt is made to outline the future of this type of stentless xenograft and to justify that its cautious use should probably be extended down to the over 50 year age patient cohort.

Journal Article↗
PubMed1999

Economic evaluation of high-dose and low-dose aprotinin therapy during cardiopulmonary bypass.

BACKGROUND: Aprotinin therapy is now widely used during cardiac surgery. This study examined the clinical and economic effectiveness of high-dose or low-dose aprotinin in comparison to placebo. METHODS: In a double blind, randomized study, three groups of 50 patients received high-dose aprotinin costing AUS$614 per patient (AUS$ = Australian dollars), low-dose aprotinin costing AUS$220 per patient or placebo. Resource use influenced by aprotinin therapy was measured. RESULTS: Both doses were effective in reducing chest drainage and postoperative transfusion requirements, high-dose being more effective than low-dose. Both doses reduced the rate of reoperations for hemostasis. A base case of statistically significant differences associated with the high-dose and low-dose aprotinin showed cost savings of AUS$77 and AUS$348 per patient, respectively. If the demonstrated less significant reductions in operating room and ward stay are included, these savings become AUS$463 and AUS$715, respectively. Alternately, if cross-matches are replaced by group-and-hold and cell savers are not used, the savings per patient would be AUS$196 and AUS$467, respectively. CONCLUSIONS: While high-dose aprotinin is clinically more effective than low-dose aprotinin, low-dose therapy demonstrates greater cost savings.

Aprotinin↗
PubMed1999

An exceedingly low operative mortality given by stentless autologous, homologous, and heterologous aortic valves for aortic valve replacement.

Homologous, autologous, and heterologous stentless valves were implanted into 663 patients undergoing aortic valve replacement by standard conventional methods. An exceedingly low mortality rate was achieved for the whole series, with the last consecutive 311 patients experiencing zero mortality. This analysis encompasses the hospitals' total experiences with these three stentless valves and examines only the low and zero mortalities. The three stentless valves were the aortic allograft used as a root replacement in 374 patients (mean age 43 years, 8.8% for active endocarditis), the pulmonary autograft used as a root replacement (22 patients, mean age 34 years) and the Cryolife O'Brien Model 300 stentless composite porcine glutaraldehyde-preserved aortic xenograft (267 patients, mean age 73 years, 16% 80 years or older, 55% concomitant procedures). Overall mortality rate was 1.1%. The seven deaths were essentially non-valve- and non-procedure-related. Of the last consecutive 311 patients, the mortality rate has been zero (166 allografts, 22 autografts, and 123 stentless xenografts). As a result of a careful, planned introduction of each valve and good experience and training in implant techniques, this low mortality and consecutive zero mortality suggest a "modern-day gold standard."

Adolescent↗
PubMed1999

Implantation technique of the Cryolife-O'Brien stentless xenograft aortic valve: the simple, rapid, and correct way to implant and the errors to avoid.

Implantation of the Cryolife-O'Brien Model 300 stentless composite porcine aortic xenograft valve for aortic valve replacement is different from that of other stentless valves. The valve is a symmetrical, composite, three noncoronary leaflet assembly, with a broad coaptive leaflet surface. Because the valve has only a small superior aortic wall cuff and no inferior cuff, a single continuous suture line of 3-0 polypropylene provides a rapid safe implantation in the supra-annular position. Consequently ideal recipients are elderly patients, who benefit from the short cardiopulmonary bypass time. This report describes the step-by-step technique of implantation and outlines the principles of maintaining symmetry during implantation. Errors to avoid are also discussed. This stentless valve has been used for aortic valve replacement in 267 elderly patients since 1992, with a 1.1% mortality, low morbidity, and excellent valve function.

Aortic Valve↗