Biomedical subjects

John Fuller

Publications and source records attributed to John Fuller.

14 recordsLinked to original sources

PubMed2005

Arterial conduits update.

Arterial grafting for coronary artery disease has been practiced routinely at the Epworth Hospital for 20 years. Bilateral versus single internal thoracic artery grafts is associated with improved survival, which progressively increased over the 20 years of post-surgery. The average increase in survival was 15% at 20 years. The question of whether to use the radial artery or the saphenous vein graft as supplementary grafts remains unanswered. Current patency data suggest that there is a marginal advantage of radial artery over saphenous graft patency, particularly between 5 and 10 years after surgery. However, there appears to be improved patency of the saphenous vein when used as a coronary artery bypass with the advent of aspirin, lipid-lowering and anti-hypertensive therapy.

Blood Vessel Prosthesis Implantation↗

PubMed2005

Has the in situ right internal thoracic artery been overlooked? An angiographic study of the radial artery, internal thoracic arteries and saphenous vein graft patencies in symptomatic patients.

OBJECTIVE: The right internal thoracic artery is being used infrequently despite favorable observational angiographic data. Conversely, the radial artery utilization has increased with only limited data available. The purpose of this paper is to re-evaluate the roles of the right internal thoracic artery and the radial artery grafts. METHODS: We reviewed all ischemia-directed coronary angiographic procedures from January 1996 to December 2003. A total of 219 patients had primary coronary artery bypass grafting with an internal thoracic artery and a radial artery as two of the bypass grafts. Six hundred and seventy-nine (679) graft angiograms (45 saphenous vein, 363 radial artery, 54 right internal thoracic artery and 217 left internal thoracic artery) were studied. The mean period from operation to re-angiogram was 1104+/-761 days. Angiographic outcomes were divided into groups as: (1) patent (<50% stenosis) or (2) failed (>or=50% stenosis, string sign or occluded). A generalized linear mixed model was used to analyze predictors of graft patency. Turnbull's estimates of cumulative patency were used to compare graft failure rates over time. RESULTS: A total of 632/679 (93%) grafts were patent and 47/679 (7%) grafts had failed. Empirical saphenous vein graft patency was 40/45 (89%), radial artery patency 329/363 (91%), right internal thoracic artery patency 51/54 (94%) and left internal thoracic artery patency 212/217 (98%). Pairwise comparisons of patency from the generalized linear mixed model were: LITA>RITA, OR=1.5 (P=0.5); LITA>RA, OR=5.7 (P<0.001); LITA>SV, OR=6.5 (P<0.001); RITA>RA, OR=3.9 (P=0.01); RITA>SV, OR=4.4 (P=0.01); RA>SV, OR=1.1 (P=0.7). Five-year patency estimates from the Turnbull's model were the left internal thoracic artery (95.9%), right internal thoracic artery (91.2%), the radial artery (90.6%) and the saphenous vein (81.8%). CONCLUSIONS: Consideration should be given to the routine use of both internal thoracic arteries for coronary artery bypass grafting. When additional grafts are required, there is no evidence to suggest that either the radial artery or saphenous vein is superior.

Aged↗

PubMed2004

Patient selection in ambulatory anesthesia - an evidence-based review: part I.

PURPOSE: To identify and characterize the evidence supporting decisions made in the care of patients with selected medical conditions undergoing ambulatory anesthesia and surgery. Conditions highlighted in this review include: the elderly, heart transplantation, hyper-reactive airway disease, coronary artery disease, and obstructive sleep apnea. SOURCE: A structured search of MEDLINE (1966-2003) was performed using keywords for ambulatory surgery and patient condition. Selected articles were assigned a level of evidence using Centre for Evidence Based Medicine (CEBM) criteria. Recommendations were also graded using CEBM criteria. PRINCIPAL FINDINGS: The elderly may safely undergo ambulatory surgery but are at increased risk for hemodynamic variation in the operating room. The heart transplant recipient is at increased risk of coronary artery disease and renal insufficiency and should undergo careful preoperative evaluation. The patient with reactive airway disease is at increased risk of minor respiratory complications and should be encouraged to quit smoking. The patient with coronary artery disease and recent myocardial infarction may undergo ambulatory surgery without stress testing if functional capacity is adequate. The patient with obstructive sleep apnea is at increased risk of difficult tracheal intubation but the likelihood of airway obstruction and apnea following ambulatory surgery is unknown. CONCLUSION: Ambulatory anesthesia is infrequently associated with adverse outcomes, however, knowledge regarding specific patient conditions is of generally low quality. Few prospective trials are available to guide management decisions.

Aged↗

PubMed2004

Patient selection in ambulatory anesthesia - an evidence-based review: part II.

PURPOSE: This is the second of two reviews evaluating the management of patients with selected medical conditions undergoing ambulatory anesthesia and surgery. Conditions highlighted in this review include: diabetes mellitus; morbid obesity; the ex-premature infant; the child with an upper respiratory infection; malignant hyperthermia; and the use of monoamine oxidase inhibitors. SOURCE: Medline search strategies and the framework for the evaluation of clinical evidence are presented in Part I. PRINCIPAL FINDINGS: Diabetes mellitus has not been linked with adverse events following ambulatory surgery. The morbidly obese patient is at an increased risk for minor respiratory complications in the perioperative period but these events do not increase unanticipated admissions. The ex-premature infant may be considered for ambulatory surgery if post-conceptual age is > 60 weeks and hematocrit is > 30%. The child with a recent upper respiratory tract infection is at an increased risk for perioperative respiratory complications, particularly if endotracheal intubation is required. Patients with malignant hyperthermia may undergo outpatient surgery but require four hours of postoperative temperature monitoring. Sporadic cases of drug interactions have been reported when meperidine and indirect-acting catecholamines are administered in the presence of monamine oxidase inhibitors. Ambulatory anesthesia and surgery is safe if these combinations of drugs are avoided. CONCLUSION: Ambulatory anesthesia can be performed in, and is being offered to, a variety of patients with significant coexistent disease. In many cases there is little evidence documenting the outcomes expected in such patients. Prospective observational and interventional trials are required to better define perioperative management.

Adult↗

PubMed2004

Pheochromocytoma and pregnancy: a case report and review of anesthetic management.

PURPOSE: To describe a patient diagnosed with pheochromocytoma in the third trimester of pregnancy and discuss the perioperative and anesthetic management. CLINICAL FEATURES: A 32-yr-old previously healthy woman (gravida 4, para 2) presented to our tertiary care obstetrical hospital at 34 weeks five days gestation with a history of labile blood pressure and severe hypertension. A week prior to admission she began having episodes of severe headache, dizziness, sweating and nausea. On a routine obstetric visit she was noted to be severely hypertensive with a blood pressure of 200/120 mmHg. Biochemical investigations confirmed the diagnosis of pheochromocytoma and magnetic resonance imaging demonstrated a 3 cm x 3 cm right adrenal mass. The patient was invasively monitored in the intensive care unit and treated with alpha- followed by beta-blockade with phenoxybenzamine and metoprolol. A multidisciplinary conference was organized involving endocrinology, anesthesiology, general surgery and obstetrics to determine the most appropriate management of the patient. An uncomplicated laparoscopic adrenalectomy was performed following a period of recovery after an uneventful elective Cesarean delivery. CONCLUSIONS: The primary goals in the management of pheochromocytoma in pregnancy are early diagnosis, avoidance of a hypertensive crisis during delivery and definitive surgical treatment. Timing of surgical resection will depend on the gestational age at which diagnosis is made. Cesarean section is the preferred mode of delivery when the tumour is still present. This case illustrates that with antenatal diagnosis, advanced methods of tumour localization, adequate preoperative adrenergic blockade and team planning, pheochromocytoma in pregnancy can be treated successfully.

Adrenal Gland Neoplasms↗

PubMed2004

Factors affecting patency of internal thoracic artery graft: clinical and angiographic study in 1434 symptomatic patients operated between 1982 and 2002.

OBJECTIVE: The purpose is to define factors influencing long-term patency of the internal thoracic artery (ITA) to optimize the operative strategy. METHODS: 1482 left internal thoracic artery (LITA) and 636 right internal thoracic artery (RITA) symptom-directed angiograms were studied in 1434 patients. Data were prospectively collected from patients who had primary coronary artery bypass surgery during the period 1982-2002. The mean age of patients was 59 years; 85% were male. The mean period from operation to re-angiogram was 80 months. LITA was grafted to left anterior descending coronary artery (LAD) in 82% of cases, RITA to right coronary artery (RCA) in 40% and circumflex artery in 35% of cases. Graft failure was defined as > or =80% stenosis. RESULTS: 96.3% of LITA and 88.1% of RITA grafts were patent. No patient variables were significantly associated with graft patency (age, gender, diabetes, hypertension, LVEF, NYHA, AMI). Target coronary artery was associated with patency of both LITA and RITA grafts with maximum patency when grafted to LAD (P = 0.02) RITA had the worst patency to RCA, patency for the left system was identical to LITA. Proximal anastomosis to aorta (free RITA) had significantly better patency when compared with in situ RITA to RCA system (P = 0.005) while similar patency when grafted to left system. ITA diameter and target artery diameter were not associated with graft patency. Recent operations had better RITA patency (P = 0.03). The interval from operation to angiogram was not associated with ITA patency (96% patency for LITA and 88% patency for RITA, remained stable when studied at <1, 1-4, 5-9, 10-14 and >15 years). CONCLUSIONS: Even in a patient cohort that had adverse symptoms, excellent LITA and RITA patency was achieved which almost remained constant through all time intervals studied.

Aged↗

PubMed2004

Patency of the radial artery graft: angiographic study in 209 symptomatic patients operated between 1995 and 2002 and review of the current literature.

OBJECTIVES: The purpose of this study is to define the long-term patency of the radial artery (RA) graft and review the current literature. METHODS: Two hundred and eighty-six RA symptom-directed graft angiograms were studied in 209 patients. The preoperative patient characteristics and intraoperative variables were collected prospectively from patients who had primary coronary artery bypass grafting between 1995 and 2002. A total of 166 (79%) patients were male with a mean age of 65 years. The mean period from operation to re-angiogram was 35 months. Actuarial techniques are not valid in graft patency studies as the time when the graft occluded is not known. Therefore, RA patency was analyzed at four categorical time intervals. The RA was grafted to the left anterior descending artery (LAD) in six patients (2%), diagonal (DIAG) in 29 (10%), obtuse marginal (OM) in 166 (58%), right coronary artery (RCA) in 9 (3%) and posterior descending artery (PDA) in 76 (27%) cases. The graft failure was defined as >or=80% stenosis. RESULTS: A total of 259 (91%) grafts were patent and 26 (9%) had failed. Most grafts were widely patent or occluded. The LAD/DIAG patency was 30/35 (86%), OM patency 154/166 (93%) and RCA/PDA patency 79/84 (94%). The interval from surgery to angiogram did not affect the RA graft patency (86% at <1 year, 95% at 1-3 years, 89% at 4-5 years, 96% at >5 years). CONCLUSIONS: Even in a patient cohort with adverse symptoms, excellent RA patency was achieved that remained almost constant through all time intervals studied. Better selection, harvesting and preservation may further improve early patency.

Journal Article↗

PubMed2004

Clinical trials and graft patency data in coronary artery surgery--a 30-year perspective.

The treatment of coronary artery disease, initially by medical and surgical and subsequently using percutaneous interventions, has evolved rapidly over the last 50 years. Randomized controlled clinical trials and observational studies of large cohorts have been instrumental in the evolution of the current practice of coronary artery revascularisation. This paper traces some of the historic trials of medical versus surgical therapy, surgical versus percutaneous intervention and graft patency studies. Medical therapy and percutaneous intervention are now the primary therapeutic modalities. However, there was an early recurrence rate with percutaneous intervention which has decreased with the use of drug-eluting stents. Coronary artery bypass surgery remains a major option for treating advanced coronary artery disease. Furthermore, it remains the treatment of first choice in most patients with left main coronary artery disease and those with extensive three-vessel proximal coronary artery disease, especially when associated with poor left ventricular function. The choice of a coronary artery bypass conduit is of major importance in developing a single long-term strategy for the surgical treatment of coronary artery disease. Bilateral internal thoracic artery grafting is now accepted as the treatment of choice, although not universally practiced. The role of other arterial conduits is being defined.

Journal Article↗

PubMed2004

A comparison of sequence-based polymorphism and haplotype content in transcribed and anonymous regions of the barley genome.

Direct estimates of sequence diversity provides an abundant source of DNA polymorphisms based on single nucleotide polymorphisms (SNPs). The frequency and distribution of nucleotide diversity within 23 genes associated with grain germination in barley were determined in a sample of accessions representing European cultivars, landraces, and wild barley accessions from throughout the fertile crescent. The overall nucleotide diversity ranged from 0.0021 to 0.0189 with a single nucleotide change being detected every 78 bp and insertion-deletion events being observed every 680 bp. Within the cultivated (H. vulgare) genepool, a small number of haplotypes were detected, the total number of haplotypes observed in H. spontaneum was almost double that detected in H. vulgare (46 and 26, respectively). Distinct haplotypes were observed in the H. spontaneum and landrace genepools, which are highly divergent from H. vulgare. A comparison of SNP-based haplotype data with EST-derived SSRs and genomic SSRs revealed a similar trend of decreasing variability in the cultivated genepool. However, the number of unique alleles identified in the cultivated sample was much greater with genomic SSRs (18%) compared with only 2.1% for SNPs and 3.8% for EST-derived SSRs. The potential utility of SNPs and EST-derived SSRs for association mapping in barley is discussed.

Base Sequence↗

PubMed2004

Explanations for the high risk of diabetes-related amputation in a Caribbean population of black african descent and potential for prevention.

OBJECTIVE: Diabetes-related lower-extremity amputation (LEA) rates are elevated in blacks compared with whites in the U.S., but are lower in African Caribbeans in the U.K., whereas anecdotal reports suggest high rates in the Caribbean. We aimed to establish the incidence and risk factors for diabetes-related LEA in a Caribbean population. RESEARCH DESIGN AND METHODS: We conducted an incident and prospective case-control study of case patients (individuals with diabetes having a LEA) and community-based control subjects (individuals with diabetes without a LEA) in Barbados, West Indies. Participants completed an interview and examination of risk factors for amputation, including footwear use. RESULTS: The overall 1-year incidence of LEA (n = 223) was 173 per 10(5) population and 936 per 10(5) population with diabetes (557 per 10(5) for minor amputation and 379 per 10(5) for major amputation). Women had higher amputation rates than those reported in the Global Lower Extremity Amputation Study, apart from the U.S. Navajo population. Independent risk factors for all diabetes-related LEAs were poor footwear (odds ratio [OR] 2.71 [95% CI 1.23-5.97]), elevated GHb (1.40 per percent increase [1.26-1.57]), peripheral neuropathy (1.05 per volt increase [1.03-1.08]), and peripheral vascular disease. CONCLUSIONS: Diabetes LEA rates in Barbados are among the highest in the world. Inadequate footwear independently tripled amputation risk. Education of professionals and patients, particularly about footwear and foot care, coupled with improved diabetes clinical care, is key to reducing amputation risk in this population.

Aged↗

PubMed2003

Factors affecting saphenous vein graft patency: clinical and angiographic study in 1402 symptomatic patients operated on between 1977 and 1999.

BACKGROUND: The purpose of this study was to find the preoperative and intraoperative factors that affect vein graft patency. METHODS: A total of 3715 graft angiograms in 1607 patients were studied for recurrence of angina. The preoperative patient characteristics and intraoperative variables were prospectively collected from patients who had primary coronary artery bypass grafting during the period from 1977 to 1999. A total of 1339 (83%) patients were male, with a mean age of 59 years. The mean period from operation to reangiogram was 99 months. The saphenous vein was grafted to the left anterior descending artery in 557 (15%), to the diagonal artery in 669 (18%), to the obtuse marginal artery in 1300 (35%), to the right coronary artery in 409 (11%), and to the posterior descending artery in 780 (21%) cases. Graft failure was defined as >or=80% stenosis. RESULTS: During the course of the study, 2266 (61%) grafts were patent, and 1449 (39%) had failed. The patient variables that significantly reduced graft patency were a younger age (P <.001) and an ejection fraction <30% (P =.047). Operative variables associated with reduced graft patency were small coronary artery diameter (P <.001), large conduit diameter (P =.001), and the coronary artery grafted (lowest patency in the right coronary artery and maximum patency in the left anterior descending artery territory; P =.002). The interval from operation to repeat angiogram (P <.001, with 78% patent at 1 year, 78% at 5 years, 60% at 10 years, and 50% at 15 years) and the year in which the operation was performed (more recent operations had better patency; P <.001) significantly affected graft patency. CONCLUSIONS: Saphenous vein graft patency improved over the course of the study. The best results were obtained in older patients with good left ventricular function. Large-caliber arteries on the left system, when grafted with a small-diameter vein, were associated with the best outcome.

Coronary Angiography↗

PubMed2003

Cardiac surgical audit Epworth Hospital 2002.

The cardiac surgical programme at Epworth Hospital has performed in excess of 13 000 open-heart surgical procedures between 1981 and 2003. During the audit period (2002) 411 patients underwent open-heart surgery. The 2002 Cardiac Surgical Audit confirms the very high standard of surgery. The goals for the future are to maintain the low complication rate and maintain an efficiency to reduce the financial burden on the hospital, the insurance companies and the health system.

Journal Article↗

PubMed2002

Expression of bone morphogenetic proteins (BMP), BMP receptors, and BMP associated proteins in human trabecular meshwork and optic nerve head cells and tissues.

PURPOSE: Bone morphogenetic proteins (BMPs) are multi-functional cytokines that have wide ranging effects on a variety of cells and tissues. In the present study, we profile the expression of BMPs, BMP receptors, and BMP associated proteins in the human trabecular meshwork (TM) and optic nerve head (ONH), two tissues involved in glaucoma pathogenesis. METHODS: Total RNA was isolated and subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) to examine the expression of BMP, BMP receptor, and BMP associated proteins in tissues and cultured cells from the human TM and ONH (ONH astrocytes and lamina cribrosa cells). Western immunoblotting was used to study the expression of BMP and BMP receptor proteins in cultured human TM and ONH cells. RESULTS: Both TM and ONH cells and tissues expressed mRNAs for BMP2, BMP4, BMP5, BMP7, BMP-RIA, BMP-RIB, BMP-RII, DRM (gremlin), follistatin, chordin and NMA (BAMBI). The proteins for BMP2, BMP4, BMP5, BMP7, and all three BMP receptors were expressed in cultured human TM and ONH cells. CONCLUSIONS: Members of the BMP family of genes, including BMPs, BMP receptors, and inhibitory BMP associated proteins are expressed in the human TM and ONH. These molecules may be involved in the normal formation and function of these tissues. Altered expression of members of this gene family may lead to functional changes in the TM and ONH. These genes and their respective signaling pathways merit further research to examine their possible role in glaucoma.

Aged↗

PubMed2002

Effect of cervical hard collar on intracranial pressure after head injury.

BACKGROUND: Patients suffering head trauma are at high risk of having a concomitant cervical spine injury. A rigid cervical collar is usually applied to each patient until spinal stability is confirmed. Hard collars potentially cause venous outflow obstruction and are a nociceptive stimulus, which might elevate intracranial pressure (ICP). This study tested the hypothesis that application of a hard collar is associated with an increase in ICP. METHODS: A prospective series of 10 head-injured patients with a postresuscitation Glasgow coma scale score of nine or less had ICP measurements before and after cervical hard collar application. RESULTS: Nine out of 10 patients had a rise in ICP following application of the collar. The difference in pre- and postapplication ICP was statistically significant (P < 0.05). CONCLUSIONS: Early assessment of the cervical spine in head-injured patients is recommended to minimize the risk of intracranial hypertension related to prolonged cervical spine immobilization with a hard collar.

Adolescent↗