Aortic anastomosis made easier.
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Anastomosis, Surgical↗
Biomedical subjects
D Bouchier-Hayes
Publications and source records attributed to D Bouchier-Hayes.
Risberg retroperitoneal approach to the abdominal aorta.
In a study of the best approach to the infrarenal abdominal aorta, 47 patients were compared retrospectively: 15 underwent a standard transperitoneal incision, 15 a retroperitoneal left flank incision and 17 a new modified lateral pararectus incision, the Risberg approach. Operating time, length of postoperative intubation and hospital stay, mortality rate, morbidity rate and cost were assessed. There was a significant reduction (P < 0.05) in mean(s.d.) operating time (141(21) versus 198(41) min), intraoperative cross-clamping time (74(13) versus 104(46) min) and postoperative intubation time (6.5(8.0) versus 13.3(7.3) h) associated with the Risberg retroperitoneal incision compared with the left flank retroperitoneal route. There was also a significant decrease (P < 0.02) in mean(s.d.) postoperative intubation time (6.5(8.0) versus 17.5(12.0) h), time after operation to discharge (11.0(2.4) versus 17.3(7.6) days) and hospital cost (4885(670) pounds versus 7732(580)) pounds associated with the Risberg incision compared with the transperitoneal approach. The Risberg incision gives better access to the infrarenal abdominal aorta while maintaining the advantages of other retroperitoneal approaches. This technique is recommended as the incision of choice for the retroperitoneal approach to the aorta.
Aged↗
Granulocyte-macrophage colony-stimulating factor inhibits tumour growth.
The effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on murine antitumour responses was examined. Sixty mice received Lewis lung carcinoma implants and were then randomized to receive GM-CSF 1 microgram/day, GM-CSF 0.5 microgram/day or saline for 10 days and studied with regard to tumour volume, carcass weight and food intake. Macrophage antitumour mechanisms including oxygen free radical production and nitric oxide release were studied in peritoneal macrophages after co-culture with GM-CSF in vitro and in vivo. GM-CSF 1 microgram/day decreased tumour growth after 5 days (mean(s.e.m.) 0.62(0.14) versus 1.24(0.19) cm3, P = 0.017). GM-CSF upregulated macrophage antitumour mechanisms by enhancing the in vivo production of superoxide radicals (mean(s.e.m.) 0.69(0.06) versus 0.45(0.10) nmol, P < 0.05) and nitric oxide (mean(s.e.m.) 48(3) versus 24(4) mumol, P < 0.01). GM-CSF functions through the enhancement of macrophage tumoricidal activity, suggesting a therapeutic potential for this cytokine in the tumour-bearing host.
Animals↗
Splenectomy predisposes to fungal sepsis through defective phagosome formation.
Postsplenectomy septic sequelae may be fatal, but the mechanisms are unclear. We hypothesized that peritoneal macrophage (PM phi) antimicrobial function is abnormal following splenectomy and that this may predispose to increased mortality from the fungal pathogen Candida albicans. Study 1 (in vivo): female CD-1 mice were randomized into control (C), laparotomy (L), or laparotomy+splenectomy (L + S) and inoculated with C. albicans (10(7) organisms, ip) and were studied for mortality. Study 2 (in vitro): mice were randomized to C, L, or L + S groups. Twenty-four hours later, PM phi were harvested and studied for their antifungal activity, including percentage PM phi ingestion of C. albicans and vacuolar sealing of C. albicans within PM phi, percentage C. albicans killing, and superoxide anion (O2-) generation, the mechanism by which candida are killed. Results showed decreased phagocytosis and killing of C. albicans in the L + S group (P < 0.05 vs C) and reduced vacuolar sealing (P < 0.05 vs C) but significantly higher O2- release compared to that in other groups (P < 0.05). Mortality in the L + S group from C. albicans sepsis was significantly higher than that in the other groups (60% compared to 20% in the L group and 13% in C, P < 0.02). This may have resulted from L + S-induced defective phagocytosis of C. albicans and depressed C. albicans killing but increased O2- release in response to candida. This discrepancy between decreased killing and increased O2- may result from increased leakage of O2- from more unsealed vacuoles in the L + S group. Thus, L + S may predispose to candida-induced mortality through defective PM phi intracellular candida killing while enhancing the release of O2- extracellularly from unsealed vacuoles, causing tissue injury.
Animals↗
ERCP in the management of patients having laparoscopic cholecystectomy: re-appraising current indications.
This study assessed the ability of biochemical tests and ultrasound to predict the presence of ductal calculi, and thereby refine the indications for ERCP, in patients before or after laparoscopic cholecystectomy. Thirteen of fifty-three patients investigated before laparoscopic cholecystectomy, and four of seventeen investigated after had stones confirmed at ERCP. The most sensitive indices for stones were raised serum alkaline phosphatase (0.76), aspartate transferase (0.75) and alanine transferase (0.76). The most specific indices were an abnormal ultrasound (0.92), raised serum amylase (0.78) and raised bilirubin (0.75). Serum bilirubin, amylase and ultrasound were all normal in twenty-seven patients and all of these had normal ERCPs. If patients with normal bilirubin, amylase and ultrasound were not referred for ERCP, no stones would have been overlooked and the number of ERCPs could have been reduced by 39%.
Adolescent↗
Pharmacological manipulation of acute cyclosporin ischemic renal injury with trimetazidine.
Cyclosporin has had a major impact on organ transplantation, but associated nephrotoxicity is a significant problem. Renal hypothermia, a known anti-ischemic maneuver, limits cyclosporin-ischemic renal failure. Pharmacological manipulation with an anti-ischemic agent, such as trimetazidine, may prevent cyclosporin nephrotoxicity. We tested this hypothesis in a canine single kidney model of cyclosporin-enhanced ischemic renal failure. Trimetazidine treatment was associated with significantly better biochemical and histological markers of renal function and structure. Trimetazidine may have a role to play in protecting against cyclosporin nephrotoxicity in clinical renal transplantation.
Animals↗
How much heparin? A simple in vitro test.
A simple in vitro test to calculate the dose of heparin required to achieve optimal in vivo anticoagulation during surgery has been assessed in 15 patients who subsequently underwent vascular surgery. Heparin was added to four aliquots of patients blood in vitro to give five solutions with heparin concentrations ranging from 0-0.8 units/ml of plasma. The activated partial thromboblastic times (APTT) of each of these samples was then measured and the natural log (ln) of the APTT calculated. The natural log of the APTT in vitro was then plotted against the in vitro heparin concentration. From this linear correlation the concentration of heparin required to achieve an APTT 2.5 times the normal in vitro (Hc) for the 15 different patients was calculated and ranged from 0.4-0.75 units/ml (median 0.47). Based on an estimate of the plasma volume (PV), the bolus dose of heparin given intravenously to each patient to produce an equivalent anticoagulant response in vivo was calculated (Hc x PB). Heparin boli administered ranged from 1000-2000 units (median 1500). The mean in vivo APTT achieved was 77% of the predicted value (range 62%-123%). Such an estimation of an in vivo response, by means of an in vitro test, should help to more accurately predict the effects of heparin in vivo and individualise anticoagulation dosage.
Aged↗
Neuroendocrine and haemodynamic responses to abdominal aortic cross clamp and release during high-dose opiate-oxygen-isoflurane anaesthesia.
The haemodynamic and neuroendocrine responses and beta adrenoceptor distribution associated with aortic cross clamping and release were quantified in 14 patients undergoing elective abdominal aortic aneurysm surgery using a high-dose opiate-oxygen-isoflurane anaesthetic technique. These changes were correlated with neutrophil beta adrenoceptor distribution. Aortic cross clamp application was associated with increased systemic vascular resistance (SVR), and decreased cardiac index (CI). Left ventricular stroke work index remained constant during the period of cross clamp application and following release. Cross clamp release was associated with increased CI and decreased SVR. Plasma cortisol concentrations did not change during the study period. Plasma catecholamine concentrations, although elevated prior to surgery, remained unchanged during aortic cross clamping and following release. The percentage of internalised beta adrenoceptors was elevated before surgery and was unaffected by surgical intervention. This study suggests that a high-dose fentanyl-oxygen-isoflurane anaesthetic technique in a patient population with high circulating catecholamine levels and downregulation of beta adrenoceptors is associated with cardiovascular stability and attenuated neuroendocrine responses.
Aged↗
An aggressive approach to acute superior mesenteric arterial ischemia.
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Aged↗
Spinal cord perfusion pressure in dogs after control of proximal aortic hypertension during thoracic aortic cross-clamping with esmolol or sodium nitroprusside.
BACKGROUND: Spinal cord perfusion pressure may be reduced when sodium nitroprusside is used to control proximal aortic hypertension during thoracic aortic clamping. The effect of esmolol infusion on spinal cord perfusion pressure during thoracic aortic clamping is unknown. This study compares spinal cord perfusion pressure following control of proximal hypertension with either sodium nitroprusside or esmolol during thoracic aortic clamping. METHODS: The thoracic aorta was cross-clamped for 30 min in 18 dogs anesthetized with halothane. A control group (n = 6) received no treatment of proximal hypertension during cross-clamping. In two other groups, proximal arterial pressure was controlled (100 mmHg) by infusion of either sodium nitroprusside (n = 6) or esmolol (n = 6). Brachial and femoral arterial pressures, spinal cord perfusion pressure, pulmonary artery occlusion, central venous pressures, and cardiac output were monitored. Neurologic assessment was performed 24 h following surgery. RESULTS: Femoral arterial pressure was lower with nitroprusside (14 +/- 3 mmHg) compared to esmolol (24 +/- 4 mmHg) after 15 min of aortic cross-clamping. Cerebrospinal fluid pressure increased during aortic cross-clamping in the sodium nitroprusside group (from 7 +/- 5 to 16 +/- 6 mmHg) but not in esmolol or control groups. Spinal cord perfusion pressure was lower with nitroprusside at 15 min of aortic cross-clamping (2 +/- 4 mmHg) compared to control (15 +/- 7 mmHg) and esmolol groups (17 +/- 11 mmHg). Esmolol infusion reduced cardiac output and increased ventricular filling pressures compared to control and nitroprusside groups. CONCLUSIONS: Esmolol was associated with greater spinal cord perfusion pressure, but adverse hemodynamic effects, when compared with nitroprusside during thoracic aortic cross-clamping. When only surviving dogs (4 control, 5 esmolol, 6 nitroprusside) are considered, the incidence of neurologic deficit was greater in nitroprusside-treated dogs than in either control or esmolol-treated dogs. No difference in outcome was present when all dogs are considered.
Adrenergic beta-Antagonists↗
Perioperative immune modulation.
BACKGROUND: The effects of operative trauma on systemic immunity were studied. The relative effects of skin incision and of breaching the peritoneum were determined. In addition, the role of the antiendotoxic agent taurolidine in preventing postoperative immune suppression was assessed. METHODS: Systemic immune responsiveness was measured as the delayed-type hypersensitivity (DTH) response to 2-4 dinitro l-fluorobenzene (DNFB) with an in vivo rat model. The effect of both laparotomy and taurolidine on the hepatic Kupffer cell population was determined by immunohistochemistry. RESULTS: This study confirmed that cellular immunity is significantly depressed after laparotomy (15.5%; range, 2.5%-24.0%) compared with unoperated controls (26.77%; range, 9.2%-38.0%). Opening the peritoneum appeared to be a critical factor in inducing this immunosuppression, in which animals undergoing a similar midline incision without opening of the peritoneum displayed minimal alteration in their DTH response (20.5%; range, 0.85%-41.5%). In addition, intraperitoneal administration of taurolidine in the perioperative period prevented this decrease in postoperative DTH response. Kupffer cell numbers were increased after intraperitoneal administration of taurolidine, compared with animals treated with intraperitoneal saline solution or unoperated controls. CONCLUSIONS: These findings confirm the presence of an operatively induced decrease in immune responsiveness and suggest that entering the peritoneum is an important factor in the induction of this effect. In addition, administration of taurolidine acts to prevent the impact of laparotomy on DTH response, possibly by preventing perioperative portal endotoxemia.
Animals↗
Flushing technique in the management of retained common bile duct stones with a T tube in situ.
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Gallstones↗
Cytokines in tumour therapy.
Cytokines are low molecular weight proteins released by cells of the immune system that have therapeutic potential in cancer. They include the interleukins, the interferons, tumour necrosis factor and the colony-stimulating factors. Cytokines are capable of producing significant and sustained responses against a number of tumours. Clinically, the highest response rates to cytokine immunotherapy have been seen in melanoma and renal cell cancer. Current efforts aim to reduce treatment-related toxicity while maintaining the efficacy of cytokines. The therapeutic potential of these agents may be increased with genetic manipulation by introducing genes encoding cytokines into tumour-infiltrating lymphocytes and certain tumour cells. However, immunotherapy remains time consuming and expensive, and further developments are necessary before it can have a definitive role in tumour management.
Colony-Stimulating Factors↗
Emergency appendicectomy: a one year audit.
A retrospective study of emergency appendicectomy over a one-year period at Beaumont Hospital was carried out. The overall normal appendicectomy rate was 22.8%, and was twice as high in women (31%) as in men (15%). Gangrenous or perforated appendicitis was present in 20% of cases. The overall mean assessment-surgery interval was 16.7 hours. Considerable variation in the use of antimicrobial agents was noted in the study, and many haematological and radiological investigations performed did not appear to improve diagnostic accuracy. Among patients with clinical features typical of appendicitis, 16% proved to have a normal appendix. These results point to a number of aspects of the diagnosis and management of appendicitis where there appears to be room for future improvement.
Acute Disease↗
Regional hypothermia protects against tourniquet neuropathy.
Ischaemic nerve injury has been suggested as the mechanism for post-tourniquet limb paralysis. As hypothermia has been shown to prolong ischaemia time in many tissues, we tested the hypothesis that cold protection would reduce tourniquet induced neural injury. In 16 male Wistar rats a tourniquet was applied to the right hind limb for 3 h. In eight rats both hind limbs were maintained at room temperature (27 degrees C) while the limb temperature was decreased to 4 degrees C by application of cold polyglycol gel packs in the remaining eight animals. Motor nerve conduction velocity (MNCV) and the amplitude of muscle motor units (AMMU) in response to nerve stimulation were measured at 0 h, 1 h and 1 week post-tourniquet release. Application of the tourniquet for 3 h abolished nerve conduction in all animals. Hypothermia resulted in a significant improvement in AMMU (5.8 +/- vs. 0.6 +/- 0.4 mv, p less than 0.05) at 1 h and in MNCV (26.6 +/- 1.6 vs. 8.1 +/- 4.4 ms-1, p less than 0.05) and AMMU (18.5 +/- 2.0 vs. 9.7 +/- 4.5 mv, p less than 0.05) at 1 week. Hypothermia without ischaemia also reduced MNCV (44.2 +/- 9.4 vs. 74.3 +/- 8.9 ms-1, p less than 0.05) and AMMU (28.1 +/- 2.8 vs. 36.3 +/- 8.4 mv, N.S.). These data indicate that hypothermia reduces normal MNCV and protects nerve function during tourniquet ischaemia. These results support the ischaemic hypothesis for post-tourniquet nerve injury. Cold protection may have clinical applications for surgical procedures performed with tourniquet ischaemia.
Animals↗
Aprotinin: the ideal anti-coagulant?
The serine proteinase inhibitor, aprotinin, significantly reduces transfusion requirements during open heart surgery. Whether this benefit is associated with an increased tendency to thrombosis has not been studied. We investigated the effect of aprotinin in an experimental arterial thrombosis model. In 17 male Sprague-Dawley rats, the infrarenal aorta was replaced with 1.0-mm diameter PTFE grafts of varying lengths. The time to graft occlusion, recorded by palpation, Doppler ultrasound and a distal bleeding test, was 20.2 +/- 1.8 min, 35.8 +/- 6.1 min and 43.7 +/- 6.6 min for grafts of 10, 7.5 and 5.0 mm respectively (r = -0.98, p less than 0.05). Following PTFE graft placement 24 Sprague-Dawley rats were given saline (n = 6), aprotinin (n = 6), heparin (n = 6), and heparin + aprotinin (n = 6). The time to occlusion was significantly prolonged in the aprotinin group (71.7 +/- 20.4 min vs. 20.2 +/- 1.8 min, p less than 0.05). The time to thrombosis for heparin + aprotinin and heparin alone was also significantly prolonged (p less than 0.05). Prothrombin times (PT) were 21.9 +/- 3.0 s for control, 29.4 +/- 6.2 s for aprotinin, 40.7 +/- 2.5 s for heparin and 39.9 +/- 14.5 s for heparin + aprotinin (p less than 0.05 vs. control for all values). Bleeding time was not prolonged with aprotinin (3.0 +/- 0.9 min vs. 2.9 +/- 0.7 min). The bleeding time was 18.9 +/- 4.1 min for heparin + aprotinin and 22.5 +/- 2.3 min for heparin alone (p less than 0.05 vs. control for both values).(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Transoesophageal pulsed wave Doppler measurement of cardiac output during major vascular surgery: comparison with the thermodilution technique.
We measured cardiac output in 12 patients undergoing elective abdominal vascular surgery at specific times during the procedure with simultaneous thermodilution and transoesophageal pulsed Doppler echocardiographic techniques. No patient had clinical evidence of valvular heart disease before surgery. Five patients had echocardiographic evidence of mitral regurgitation on colour-coded Doppler. Using Bland and Altman analysis to compare the cardiac output measurement by the two techniques, the Doppler method overestimated the cardiac output (bias = 0.86 litre min-1) compared with the thermodilution technique and there were wide limits of agreement between the two techniques (+2.4 to -4.1 litre min-1). However, in the seven patients with no evidence of mitral regurgitation, closer agreement (bias 0.14 litre min-1) and narrower limits (+1.6 to -1.3 litre min-1) were observed. We conclude that, in patients with competent mitral valves, transoesophageal echocardiograph may provide accurate determination of cardiac output.
Aorta↗