Delayed Profunda Femoris Artery Bleeding After Intramedullary Nailing of an Unstable Intertrochanteric Fracture: A Case Report.

CASE: A 75-year-old man underwent intramedullary nailing for an unstable intertrochanteric fracture of the left hip. After surgery and postoperative recovery, he was transferred to a rehabilitation ward. He was able to mobilize at 2 days postoperatively; at 2 weeks postoperatively, he developed the sudden onset of tachycardia, hypotension, and a large hematoma on the left thigh. Following immediate resuscitation, a computed tomography (CT) angiogram demonstrated a bleed from a branch of the profunda femoris artery. The 3-dimensional CT reconstruction implicated the displaced lesser trochanter osseous fragment as the cause of the hemorrhage. CONCLUSION: Surgeons should be aware of this rare complication and the possible etiology of fracture displacement as the cause of a delayed-onset bleed after intramedullary nailing, and they should also be cognizant of the subsequent optimal management.

Effects of gelatine and medium molecular weight starch as priming fluid in cardiopulmonary bypass--a randomised controlled trial.

Perioperative volume replacement after cardiopulmonary bypass is complicated by post-bypass systemic inflammatory process. The aim of this study was to assess the effects of using two different colloid solutions as priming fluids in cardiopulmonary bypass. The study's primary end point was to measure the amount of fluid replacement needed during and post-cardiopulmonary bypass; blood loss, change in blood profile and intraocular pressure were secondary end points, used as measures of plasma oncotic pressures. Patients undergoing coronary artery bypass grafting were recruited. Both patients and surgeons were blinded to receive either Gelofusine or Voluven as priming fluids. At fixed intervals during cardiopulmonary bypass, the patients had their intraocular pressures measured. Intra and postoperative fluid replacement was in the form of 4.5% human albumin and the amount was recorded for each subject. The result did not show any significant differences in the amount of fluid needed to be replaced, in blood loss or in blood profile between the two groups. However, it showed an increase in intraocular pressure in both groups once cardiopulmonary bypass commenced. The average intraocular pressure was higher in the Gelofusine group compared to the Voluven group. The significant increase in intraocular pressure measurements in the Gelofusine group compared to the Voluven group support the hypothesis that Voluven maintains the plasma oncotic pressure better and reduces fluid shift.

Left atrial myxoma in transplanted heart.

Primary cardiac tumours are discovered in about 1 in 2000 necropsies. Cardiac myxomas make up half of all benign intracardiac tumours. Seventy five per cent are located in the left atrium. The first left atrial myxoma arising from the left atrium of a transplanted heart is reported.

Vasorelaxant properties of isolated human radial arteries: comparison with internal mammary arteries.

Radial arteries, used in revascularisation surgery, are prone to spasm. We have examined the ability of nitrovasodilators, calcium channel blockers, and K(ATP) channel openers to cause vasodilation, and to attenuate contractions due to depolarisation and receptor activation in radial and mammary arteries used in coronary artery bypass graft surgery. Two to three millimetre rings of artery obtained from patients at surgery were studied in organ baths in vitro. Constriction to KC1 and phenylephrine was examined before and again after treatment of the rings with drug or vehicle. Calcium channel blockers were the only compounds to inhibit contractions to both KC1 and phenylephrine. Sodium nitroprusside attenuated constriction to phenylephrine but not KC1 in both vessels. K(ATP) channel openers similarly attenuated constriction to phenylephrine in radial arteries but were much less effective in mammary arteries. These studies support the continued use of calcium blockers after revascularisation with radial artery but suggest that other classes of drug may be as effective at minimising spasm due to receptor mediated constriction.

Is hydrogen peroxide an EDHF in human radial arteries?

In human radial arteries, a nitric oxide/prostanoid-independent mechanism that has the pharmacological characteristics of an EDHF contributes to endothelium-dependent relaxation. H2O2 can act as an EDHF in some vascular beds. We examined the hypothesis that endogenously produced H2O2 mediated the nitric oxide/prostanoid-independent relaxation to carbachol in radial arteries obtained from patients undergoing coronary artery bypass surgery. Superoxide levels, measured by chemiluminescence, were similar in radial and internal mammary arteries, but immunohistochemical staining for Cu/Zn superoxide dismutase (SOD) was lower in endothelium from radial arteries. In organ chamber studies, neither addition of catalase nor addition of SOD to the bathing fluid modified nitric oxide/prostanoid-independent relaxations to carbachol in radial arteries. However, nitric oxide-dependent vasorelaxation was enhanced in the presence of SOD. Thus the nitric oxide/prostanoid-independent relaxation to carbachol is not due to H2O2 and, unlike nitric oxide-mediated vasorelaxation, is not attenuated by superoxide. Blood vessels showing EDHF-mediated relaxations resistant to oxidative stress may provide favorable outcomes in revascularization surgery.

The aortic Elan stentless aortic valve: excellent hemodynamics and ease of implantation.

The superior performance of stentless aortic valves with improved left ventricular hypertrophy regression and greater effective orifice area is proven. The Aortech Elan stentless valve (AESV) is a glutraldehyde preserved porcine valve with a pericardial reinforced inflow tract and a scalloped outflow to reduce bulk. We present the early results of AESV implantation at our institution. The first 41 consecutive recipients of the AESV at our unit, between November 1999 and December 2000, were studied. Mean preoperative New York Heart Association functional class (NYHA) status was 3.00 +/- 0.1. Patients requiring a bioprosthesis with suitable anatomy routinely received this implant. The AESV was implanted, either with an interrupted or continuous suture to the inflow tract and a continuous suture to the outflow tract. Transthoracic echocardiography was performed at 6 to 9 weeks after surgery, and aortic transvalvular gradients, flow velocities, and effective orifice areas (EOA) were calculated. In the early postoperative period, two patients with coronary artery disease died of low cardiac output. Echocardiography demonstrated competent valves. At follow-up, one patient was shown to have mild to moderate perivalvular leak with minimal symptoms. Two patients with aortic regurgitation secondary to bacterial endocarditis had no evidence of infection at 3 months after surgery. Mean transvalvular gradient was 6.91 +/- 0.87 mm Hg and mean effective orifice area was 1.18 +/- 0.04 cm(2)/m(2) at a mean of 8.4 weeks after surgery. AESV recipients for native aortic endocarditis were free from infection and regurgitation. The Elan stentless aortic valve demonstrates excellent early hemodynamic results, with very low transvalvular gradients, good flow characteristics and low regurgitation incidence. Ease of implantation is evidenced by favorable ischemic times. This valve may offer an option to homograft in acute aortic endocarditis. Long-term results are awaited.

Six-year follow-up of the Toronto stentless porcine valve.

Stentless valves in the aortic position have been shown to have superior hemodynamic performance to stented valves and have now been shown to increase survival. We report the medium-term results from a single center of 229 Toronto (SPV) aortic valve replacements between 1994 and 2000. The mean age of the patients was 72 years (range, 41-87 years). The mean Euroscores were 6.2 (+/-0.13) and Parsonnet scores of 16.8 (+/-0.5). Concomitant coronary artery bypass grafting was performed in 125 (55%) of patients, eight patients had additional mitral valve replacements and ten were redo procedures. Hospital mortality was 3.5%. The mean follow-up period was 45 (7-81) months. The actuarial survival was 92.4% (+/-1.4%) at one year and 76.2% (+/-3.5%) at five years. There were 37 late deaths (4.7% per patient years). There were 3 patients with prosthetic valve endocarditis (0.38% per patient years), two of whom died. Stroke occurred in 13 patients (1.6% per patient years), five of whom died. None of these events were known to be valve related. There was no incidence of structural valve dysfunction and no valves have been explanted. At follow-up, the mean transvalvular gradient was 4.2 mm Hg (range, 0.9-12.7 mm Hg). No aortic incompetence (AI) was seen in 88% of patients with trivial or mild AI in 11% of patients and moderate AI in one patient. This series shows acceptable early and medium-term results in an elderly population with a high incidence of coronary artery disease.

Pharmacological characterisation of endothelium-dependent relaxation in human radial artery: comparison with internal thoracic artery.

OBJECTIVE: The aim of this study was to investigate the contribution of nitric oxide/prostanoid-independent pathways to endothelium-dependent vasorelaxation in human conduit arteries. METHODS: Rings of internal thoracic artery (ITA) and radial artery (RA) taken from patients undergoing coronary artery bypass graft surgery were suspended in 10-ml organ baths and relaxation to carbachol and bradykinin studied in the presence and absence of nitric oxide synthase (NOS) inhibitors and potassium channel blockers. RESULTS: No significant relaxation to carbachol or bradykinin was observed in ITA after NOS inhibition. In contrast, in RA less than 40% attenuation of relaxation to carbachol or bradykinin was achieved with any of the NOS inhibitors. In the presence of 20 mM K+ relaxation to carbachol and bradykinin was inhibited by 28 +/- 9% and 42 +/- 9% while in the presence of L-NAME 200 microM + 20 mM K+ relaxation was inhibited by 66 +/- 6% and 70 +/- 4% respectively in this artery. Tetraethylammonium, glibenclamide, apamin and iberiotoxin had little effect on relaxation to carbachol but charybdotoxin alone and charybdotoxin plus apamin attenuated relaxation to carbachol by 23 +/- 4% and 49 +/- 9% in RA. In the presence of L-NAME 200 microM attenuation of these relaxations were increased to 60 +/- 4% and 78 +/- 4%. CONCLUSION: In ITA relaxations to carbachol and bradykinin were mediated via nitric oxide. In contrast in RA, a conduit vessel of similar diameter, both nitric oxide-dependent and independent pathways appeared to contribute to vascular relaxation. This nitric oxide-independent relaxation involved opening of Ca2+ activated potassium channel(s). The existence of alternative pathways mediating endothelium-independent relaxation could be important under pathological conditions and may contribute to the long term survival of radial artery grafts.

Randomized controlled trial of stented and stentless aortic bioprotheses: hemodynamic performance at 3 years.

A randomized prospective trial was undertaken to compare the hemodynamic performance and left ventricular regression after aortic valve replacement with the Toronto SPV stentless bioprosthesis and the Carpentier Edwards SAV (CE) bioprosthesis. Forty patients were randomized after the annular and sinotubular diameters had been measured. Early hemodynamic measurements were made with a thermodilution cardiac output catheter, and echocardiography was used thereafter. Left ventricular mass was assessed using magnetic resonance imaging (MRI) at 1 week, 6 months, and 32 months. The mean annular size was 25.3+/-2.2 mm (CE) and 25.5+/-1.5 mm (Toronto), although it was possible to implant valves with a mean diameter 3 mm larger in the stentless group (26.0+/-1.7 mm cf. 23.0+/-1.7 mm). Hemodynamic performance in the first 24 hours showed no significant difference between the groups, but there was a trend for shorter ventilation time and shorter stays in the intensive therapy unit in the stentless group. Echocardiography showed superior transvalvular gradients in the stentless group at 1 week (mean 5.5+/-3.1 mm Hg cf. 8.9+/-2.5 mm Hg), and this difference was maintained at a mean follow-up time of 32 months (3.5+/-0.6 mm Hg cf. 6.3+/-0.6 mm Hg). Similar regression of left ventricular mass was seen in both groups at 6 months, but at 32 months, measurement in diastole showed a reduction of 38% (P<.01) in the stentless group compared with 20% (P = ns) in the stented group, and measurements in systole showed a 23% (P<.01) and 13% (P = ns) reduction, respectively. This study confirms that a larger stentless valve can be implanted into a given size of aortic annulus with superior residual aortic valve gradients. These lower gradients seem to result in improved long-term regression of left ventricular mass as measured by MRI.

Ventricular remodelling and revascularization in severe left ventricular dysfunction.

OBJECTIVE: To evaluate the role of surgical revascularization in the presence of severe, global impairment of left ventricular function without discrete aneurysm formation or mitral regurgitation. The high mortality and morbidity associated with this group, together with the limited benefits tend to prompt referral for cardiac transplantation. METHODS: Fifty-three patients initially referred for transplantation, in addition to coronary revascularization, underwent mitral annuloplasty (group A = 23), free wall remodelling by endoaneurysmorrhaphy (group B = 17) or mitral annuloplasty and free wall reconstruction (group C = 13). The mean ages were 59, 56 and 57 years for groups A, B and C, respectively. Detailed assessment of pre- and post-operative physical and psychological status were carried out. RESULTS: Follow-up was for a mean period of 22-26 months. All patients reported substantial improvement in quality of life, both physical and psychological parameters and in NYHA functional class status. Objective evidence of improvement in ejection fraction was seen in all three groups but especially in group A. There were five early deaths, four were due to inadequate revascularization due to the poor quality of target vessels. There were three late deaths and one patient that required transplantation. CONCLUSION: We conclude that patients with severe left ventricular dysfunction can be candidates for surgical revascularization and optimization of ventricular geometry with acceptable mortality. The importance of achieving complete revascularization is emphasized in this series.

A three year experience with the toronto stentless porcine valve.

In the three year period from March 1994, 112 Toronto Stentless Porcine Valves (SPV TM) were implanted in the Western Infirmary, Glasgow. There were 55 males and 57 females aged between 45 and 86 years (mean 70.9 +/- 7.2 yrs). The mean preoperative aortic gradient was 89 +/- 27 mmHg. Fifty-three patients (47%) had an isolated first time aortic valve replacement. Myocardial revascularisation was carried out in 51 patients (46%) with a mean of 1.7 +/- 0.9 coronary bypass grafts per patient. Six patients (5.3%) had associated mitral valve procedures and six patients (5.3%) had previous open heart surgery. Four patients (3.6%) had a minimally invasive procedure. There was one perioperative death (0.9%) which was not valve related. Of the 111 survivors there were three late deaths (cerebrovascular accident at two months and congestive cardiac failure at two months and four months). Two patients developed prosthetic valve endocarditis at three and five months respectively, one requiring a repair of a periprosthetic leak. To compare the effects of stented and stentless prostheses on early haemodynamic function and late left ventricular mass regression, a prospective randomized clinical trial was conducted. Following valve sizing, 20 patients were randomized to receive a Carpentier-Edwards SAV stented bioprosthesis (mean annular size-25.3 mm, mean valve size-23 mm) of which eight also had bypass grafts. Twenty patients were randomized to receive a Toronto SPV (mean annular size-25.5 mm, mean valve size-26 mm) of which nine had bypass grafts. The stentless valve group had a longer ischaemic time (77.9 +/- 20.9 min v 60.9 +/- 21.9 min) and bypass time (101.7 +/- 27.1 min v 82.9 +/- 20.2 min). Using continuous cardiac output monitoring, no statistically significant differences were found in early haemodynamic indices although the stentless group required less inotropes and had a shorter ventilation time (16.1 +/- 4.2 hrs v 55.2 +/- 104.9 hrs) and intensive care stay (1.1 +/- 0.2 days v 4.6 +/- 8.3 days). Mean and peak aortic gradients one week postoperatively were lower in the stentless group (5.6 +/- 3 mmHg v 8.9 +/- 2.3 mmHg and 12.5 +/- 7.8 mmHg v 24.4 +/- 8.8 mmHg respectively). Magnetic resonance imaging at six months showed a 15% reduction in the end systolic muscle mass index in the stented group but a greater reduction of 29% in the stentless group. This study shows that despite requiring a more demanding technique of insertion, aortic valve replacement with the Toronto stentless porcine valve can produce satisfactory early clinical results.

Breaking the rules! Cardiac injury from remote entry sites.

An unusual case of penetrating injury to the heart is reported. This presented late, after an initial silent period. A high index of suspicion must be maintained when chest injuries are managed conservatively. If there is doubt, a subxiphoid pericardial window may allow cardiac injury to be excluded.

Alterations in renal microcirculation during cardiopulmonary bypass.

BACKGROUND: This study was designed to investigate renal microvascular changes during cardiopulmonary bypass. METHODS: Kidneys were harvested from each of four groups of 6 pigs. Group A were anesthetized and heparinized only. The remaining three groups underwent cardiopulmonary bypass at 28 degrees C, group B for 30 minutes and groups C and D for 120 minutes; group D had an additional 30 minutes of normothermic perfusion at the end of the experiment. Renal cortical blood flow was measured using radiolabeled microspheres. Microvascular morphology was defined by corrosion casting and scanning electron microscopy. RESULTS: In group A, renal vascular resistance was 61+/-5.1 mm Hg x mL(-1) x min(-1). This value decreased to 28+/-7.8 in group B and 25+/-4.0 in group C (p < 0.05), and increased in group D to 40+/-4.1 (p < 0.05 versus groups A, B, and C). Cortical thickness, as measured by microvascular casts in groups A, B, and C, was 33, 34, and 31 mm, respectively, with equal distribution of the resin to the superficial and deep cortex but was significantly reduced in group D to 22 mm (p < 0.05 versus groups A, B, and C), with failure of the resin to fill the superficial cortical layer. Diameters of glomeruli as seen on the casts were 111+/-10.38 microm in group A, 100+/-9.24 microm in group B, and 82+/-4.4 microm in group C (p < 0.05 group A versus group C). The glomeruli from group D were still significantly smaller than group A (93+/-10.35 microm, p < 0.05). Mean glomerular capillary diameters were 4.65+/-0.26 microm in group A, 3.9+/-0.16 microm in group B, 3.6+/-0.19 microm in group C, and 3.65+/-0.3 microm in group D (p < 0.05 group A versus groups B, C, and D). CONCLUSIONS: Hypothermic nonpulsatile cardiopulmonary bypass decreased renal vascular resistance, but the superficial and deep layers of the cortex were perfused equally. Glomeruli were reduced in size because of capillary narrowing. This was consistent with diversion of blood through bypass channels. With restoration of normothermia, underperfusion of the superficial cortex occurred, with potential for damage to these nephrons during the increased metabolic demands of rewarming.

Osteonecrosis of the calcaneum in a heart transplant recipient.

Avascular necrosis affects 3% of transplant recipients. In the lower limb, the femoral heads or condyles may be involved. We report the hitherto unrecorded complication of avascular necrosis of the calcaneum. Conservative management resulted in resolution without long-term complications.

Back from the dead: extracorporeal rewarming of severe accidental hypothermia victims in accident and emergency.

Severe accidental hypothermia in an urban environment is usually associated with drug or alcohol abuse or serious illness in elderly or debilitated patients. In the presence of cardiovascular instability, extracorporeal rewarming by cardiopulmonary bypass is the gold standard of treatment of such patients. Three cases of profound hypothermia with circulatory collapse are presented. Each was successfully resuscitated to a full neurological recovery using this method in an accident and emergency (A&E) department, although one died later of respiratory complications. All three cases had a serum potassium in the normal range at the start of treatment. Where facilities exist, extracorporeal rewarming can be performed in A&E for patients with profound hypothermia and circulatory collapse. Cardiopulmonary resuscitation must be continued throughout the rewarming process.

Marfanoid aneurysm in donor aorta after transplantation.

A case is reported of dissecting aneurysm of the donor ascending aorta and root 4 years after orthotopic cardiac transplantation. The pathology raises the possibility of Marfan's syndrome in the donor.

Left atrial myxoma in a preschool child.

A case of left atrial myxoma successfully removed using cardiopulmonary bypass in a 5-year-old child is presented. Review of the literature emphasizes the rarity and clinically aggressive behavior of this tumor in this age group.

The effects of cardioplegic arrest and reperfusion on the microvasculature of the heart.

OBJECTIVES: Despite laboratory evidence of leucocyte involvement in reperfusion injury, cardiac surgical clinical trials do not support the therapeutic effectiveness of leucocyte filtration. Furthermore, the direct effects of crystalloid cardioplegia and reperfusion on the capillaries of the heart have yet to be elucidated. We tested the effects of cardioplegic arrest and reperfusion both with and without leucocyte depletion, in a model of cardiopulmonary bypass that mimics clinical cardiac surgical conditions. METHODS: Four groups of Landrace pigs were studied. Group A (n = 6) underwent 30 min of hypothermic (28 degrees C) cardiopulmonary bypass. Groups B (n = 6), C (n = 6) and D (n = 6) also had 90 min of cardioplegic arrest. Group C was then reperfused with whole blood, while Group D was reperfused with leucocyte-depleted blood. Microvascular methylmethacrylate corrosion casts were made at the end of the experimental period. Myocardial vascular anatomy was defined by electron microscopy and capillary abundance derived from this and from the weight of casts from representative areas. Leucocyte deposition was assessed using radioisotope-labelled leucocytes. Ischaemic damage to tissues was graded according to light and electron microscopic findings. RESULTS: In Group A the mean (+/- S.D.) vascular cast weight/volume of myocardium (density) was 125 +/- 9 mg/mm3. After cardioplegic arrest (Group B), it fell to 74 +/- 7 mg/mm3 (P < 0.0001) due to absence of capillaries, although arterioles, venules and non-nutritive bypass vessels remained patent. Following reperfusion with whole blood (Group C), capillary numbers partially recovered but luminal diameters were reduced with a cast density of 94 +/- 5 mg/mm3 (P < 0.0001 versus Group A and B). Leucocyte-depleted (87-92%) reperfusion in Group D did not affect cast density (90 +/- 3 mg/mm3; P = 0.17). Coronary vascular resistances in Groups C and D rose slightly, but not significantly, during reperfusion. CONCLUSIONS: Following cardioplegic arrest, microvascular changes are marked. These changes are partially reversed by 30 min reperfusion. Leucocyte depletion does not ameliorate these effects in this model.

Emergency bypass without bypass!

We present 2 cases of failed coronary angioplasty, with hemodynamic compromise, where emergency coronary artery bypass grafting was performed without cardiopulmonary bypass. The hypodynamic nature of the stunned myocardium in this circumstance allows this technique to be applied with relative ease to accessible vessels. As a consequence, reduced morbidity and hospital stay can be anticipated.