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At least 163 records · Page 9Linked to original sources
PubMed1993

Short time-scale LV systolic dynamics: pressure vs. volume clamps and effect of activation.

We recently proposed a new model-based approach to quantifying short time-scale left ventricular (LV) systolic dynamics. In this study we examine the hypothesis that the quantitation of LV dynamics using the proposed approach is independent of external mechanical perturbations and the level of activation. Mechanical perturbation independence was assessed in seven isolated ferret hearts in which controlled changes in pressure (pressure clamp) or volume (volume clamp) were introduced at the time of peak isovolumetric pressure (protocol 1), and responses to these clamps were analyzed over the first 16 ms. The model described both pressure- and volume-clamps responses equally well. Model parameters were not different among various pressure clamps, and parameters estimated from volume clamps could accurately predict responses to pressure clamps [r2 range: 0.993-0.999; normalized root-mean-square error (NRMSE) range: 2.35-5.86%]. To examine activation independence, volume- (4 hearts) and pressure-clamp (4 hearts) responses were obtained and analyzed for baseline and postextrasystolic potentiated beats in a manner similar to protocol 1. The model parameter values estimated from the baseline state accurately predicted responses for the postextrasystolic potentiated state (r2 and NRMSE range for volume-clamp data: 0.989-0.998 and 3.35-6.88%, respectively; r2 and NRMSE range for pressure-clamp data: 0.992-0.996 and 4.26-5.23%, respectively). Thus the proposed approach can dissect the contributions of changes in activation from those due to changes in contractile unit properties on the function of the intact LV.

Animals↗
PubMed2004

The early effects of delayed cord clamping in term infants born to Libyan mothers.

This study was conducted to evaluate the haematological effects of the timing of umbilical cord clamping in term infants 24 h after birth in Libya. Mother-infant pairs were randomly assigned to early cord clamping (within 10s after delivery) or delayed clamping (after the cord stopped pulsating). Maternal haematological status was assessed on admission in the delivery room. Infant haematological status was evaluated in cord blood and 24 h after birth. Bilirubin concentration was assessed at 24 h. 104 mother-infant pairs were randomized to delayed (n=58) or early cord clamping (n=46). At baseline the groups had similar demographic and biomedical characteristics, except for a difference in maternal haemoglobin, which was significantly higher in the early clamping group (11.7 g/dL, SD 1.3 g/dL versus 10.9 g/dL, SD 1.6 g/dL; P=0.0035). Twenty-four hours after delivery the mean infant haemoglobin level was significantly higher in the delayed clamping group (18.5 g/dL versus 17.1 g/dL; P=0.0005). No significant differences were found in clinical jaundice or plethora. Surprisingly, blood analysis showed that two babies in the early clamping group had total serum bilirubin levels (> 15 mg/dL) that necessitated phototherapy. There were no babies in the late clamping group who required phototherapy. Three infants in the delayed clamping group had polycythaemia without symptoms, for which no partial exchange transfusion was necessary. Delaying cord clamping until the pulsations stop increases the red cell mass in term infants. It is a safe, simple and low cost delivery procedure that should be incorporated in integrated programmes aimed at reducing iron deficiency anaemia in infants in developing countries.

Adult↗
PubMedDate not supplied

Management of juxtarenal aortic aneurysms and occlusive disease with preferential suprarenal clamping via a midline transperitoneal incision: technique and results.

Surgical management of juxtarenal aortic (JR-Ao) aneurysms and occlusive disease may include supraceliac aortic clamping, a retroperitoneal approach, or medial visceral rotation. The authors report their results using preferential direct suprarenal aortic clamping via a midline transperitoneal incision. Between July 1, 1992, and July 31, 2001, they treated 58 patients with JR-Ao disease (44 aneurysmal, 14 occlusive) via a midline incision without medial visceral rotation. Preferential suprarenal aortic clamping was used in 53 cases (42 proximal to both renal arteries, 11 proximal to the left renal artery only) and supraceliac or supramesenteric clamping in 5 cases when there was insufficient space for an aortic clamp between the superior mesenteric artery and renal arteries. This strategy avoided mesenteric ischemia associated with supraceliac clamping in the majority of cases and afforded better exposure of the right renal artery than obtainable with a left retroperitoneal approach or medial visceral rotation. Eleven patients underwent concomitant renal revascularization. Critical adjuncts included the following: (1) selective left renal vein (LRV) division if the vein stump pressure was < 35 mm Hg (suggesting sufficient renal venous collaterals existed), (2) bilateral renal artery occlusion during aortic clamping to prevent thromboembolism, (3) flushing of aortic debris before restoring renal perfusion, and (4) routine administration of perioperative intravenous mannitol and renal-dose dopamine. Patients with type IV thoracoabdominal aneurysms, ruptured aneurysms, or JR-Ao disease approached via a retroperitoneal incision (severely obese patients, re-do aortic surgery) were excluded. No patients died or required dialysis during their hospital stay. The LRV was divided in 12 (21%) cases and reanastomosed in 2 cases (elevated stump pressures). The average suprarenal clamp time was 26 minutes (range, 10-60). Postoperative serum creatinine remained > 0.5 ng/dL above baseline in 3 (5%) patients. These results support suprarenal aortic clamping with a midline transperitoneal incision as the optimal strategy for treating juxtarenal aortic aneurysms and occlusive disease. The authors believe that selective left renal vein division enhances juxtarenal aortic exposure, and routine administration of renal protective agents, along with occlusion of both renal arteries during suprarenal aortic clamping, are critical adjuncts in performing these operations.

Aortic Aneurysm, Abdominal↗
PubMed1999

Proximal clamping levels in abdominal aortic aneurysm surgery.

In the surgical treatment of abdominal aortic aneurysm, the single proximal cross-clamp can be placed at 3 alternative aortic levels: infrarenal, hiatal, and thoracic. We performed this retrospective study to evaluate the advantages and disadvantages of the 3 main aortic clamping locations. Eighty patients presented at our institution with abdominal aortic aneurysms from March 1993 through May 1998. Fifty of these patients had intact aneurysms and underwent elective surgery, and 30 had ruptured aneurysms that necessitated emergency surgery. Proximal aortic clamping was applied at the infrarenal level in 24 patients (22 from the intact aneurysm group, 2 from the ruptured group), at the hiatal level in 34 patients (22 intact, 12 ruptured), and at the thoracic level (descending aorta) via a limited left lateral thoracotomy in 22 patients (6 intact, 16 ruptured). Early mortality rates (within 30 days) were 4% (2 of 50 patients) among patients with intact aneurysms and 40% (12 of 30 patients) among those with ruptured aneurysms. In the 2 patients from the intact aneurysm group, proximal aortic clamps were applied at the hiatal level. In the ruptured aneurysm group, proximal aortic clamps were placed at the thoracic level in 10 patients, the infrarenal level in 1, and the hiatal level in 1. According to our study, the clinical status of the patient and the degree of operative urgency--as determined by the extent of the aneurysm--generally dictate the proximal clamp location. Patients who present with aneurysmal rupture or hypovolemic shock benefit from thoracic clamping, because it restores the blood pressure and allows time to replace the volume deficit. Infrarenal placement is advantageous in patients with intact aneurysms if there is sufficient space for the clamp between the renal arteries and the aortic aneurysm. In patients with juxtarenal aneurysms, hiatal clamping enables safe and easy anastomosis to the healthy aorta. Clamping at this level also helps prevent late anastomotic aneurysm formation, which is frequently encountered after inadvertent anastomosis of the graft to a diseased portion of the aorta. Further studies are needed in order to confirm these results.

Adult↗
PubMed2001

Suprarenal or supraceliac aortic clamping during repair of infrarenal abdominal aortic aneurysms.

Suprarenal or supraceliac aortic clamping during repair of infrarenal abdominal aortic aneurysms can be complicated by renal, hepatic, and intestinal ischemia. To determine whether suprarenal or supraceliac clamping increases morbidity and mortality we retrospectively reviewed our recent nonrandomized experience. Between January 1993 and December 1998, 716 patients underwent elective (n=682) or urgent (n=34) infrarenal abdominal aortic aneurysm repair. Infrarenal clamping was used in 516 (72. 1 %) and suprarenal or supraceliac clamping in 200 (279%). The suprarenal/supraceliac group had significantly more older patients (> or = 70 years of age) (65.5% vs 477%) and a higher incidence of preoperative renal insufficiency (75% vs 5.5%). Suprarenal or supraceliac clamping was used during repair of ruptured (n=25), juxtarenal (n=7), or inflammatory abdominal aortic aneurysms (n=4); during concomitant renal or visceral revascularization (n=43); in other difficult settings (n=13); or at the surgeon's discretion (n=108). The decision for such clamping was always made during surgery In treating ruptured aneurysms, suprarenal/supraceliac clamping (25/200) was used more often than infrarenal clamping (9/516) (12.5% vs 1.74%). Operative times were similar in both groups, but transfusion requirements and length of hospital stay were slightly greater in the suprarenal/supraceliac group. Perioperative mortality was 3.1% overall, but higher in the suprarenal/ supraceliac group than in the infrarenal (75% vs 1.4%). Postoperative complications developed in 26 (13%) of patients who underwent suprarenal/supraceliac clamping. Abdominal re-exploration was required in 9 other patients. We conclude that, despite associated comorbidities, elective suprarenal/supraceliac clamping during infrarenal abdominal aortic aneurysm repair is safe, facilitates repair, and does not significantly increase mortality.

Aged↗
PubMed2002

Effect of delayed cord clamping on iron stores in infants born to anemic mothers: a randomized controlled trial.

OBJECTIVE: To study the effects of cord clamping on iron stores of infants born to anemic mothers at 3 months of age. DESIGN: Randomized controlled trial. SETTING: Teaching hospital. METHODS: Infants born to mothers with hemoglobin (Hb)<100 g/L were randomized at delivery to either immediate cord clamping (early group) or cord clamping delayed till descent of placenta into vagina (delayed group). The outcome measures were infant's hemoglobin and serum ferritin 3 months after delivery. RESULTS: There were 102 neonates randomized to early (n = 43) or delayed cord clamping (n = 59). The groups were comparable for maternal age, parity, weight and supplemental iron intake, infant s birth weight, gestation and sex. The mean infant ferritin and Hb at 3 months were significantly higher in the delayed clamping group (118.4 microg/L and 99 g/L) than in the early clamping group (73 microg/L and 88 g/L). The mean decrease in Hb (g/L) at 3 months adjusted for co-variates was significantly less in the delayed clamping group compared to the early clamping group (-1.09, 95% CI-1.58 to -0.62, p >0.001). The odds for anemia (<100 g/L) at 3 months was 7.7 (95% CI 1.84-34.9) times higher in the early compared to the delayed clamping group. CONCLUSION: Iron stores and Hb in infancy can be improved in neonates born to anemic mothers by delaying cord clamping at birth.

Adult↗
PubMed1989

Mechanical performance of pin clamps in external fixators.

Insufficient holding strength on a pin within a clamp may result in the diminution of the overall fixation rigidity as well as pin movement at the pin-bone interface. In this study the holding strength of pin fixation clamps in two representative external fixators (Hoffmann and Orthofix) was evaluated by determination of the torque resistance of pins within a clamp. In the standard Hoffman clamp, the pin-clamping effect was satisfactory in the symmetric two-, three-, and four-pin configurations, whereas the standard Orthofix clamp provided higher holding strength in the symmetric two- and three-pin configurations. All other pin configurations in both clamps resulted in a high variation of pin torsional resistance, and sometimes one of the pins registered low or had no resistance to torsion. The results indicated that the holding power of the clamps was adequate only if certain guidelines were followed at the time of external fixator application. An instrumented torque wrench may be helpful to assess the pin-fastening strength within the clamp. This wrench should also be used to introduce appropriate and uniform tightening torques to the pin clamp screws. However, these results do not apply to those fixators in which each pin will be tightened individually.

Fracture Fixation↗
PubMedDate not supplied

Effect of sterilization on stiffness and dimensional stability of rubber-dam clamps.

Simulated clinical conditions were used to test the effect of sterilization on rubber-dam clamp stiffness and dimension. Sixty Hygienic and Ivory W7 clamps were either steam or dry heat sterilized and compared to controls. Stiffness and dimensional change between Ivory clamp groups was significant (p<.0001); the sterilized clamps showed less change than the controls. Hygienic groups showed a significant different between the control and dry heat groups (p<.05); the sterilized clamps showed less change than the controls. The change in stiffness and interjaw width for all Ivory clamps compared to all Hygienic clamps was significant (p<.0001). The Hygienic clamps changes less than the Ivory clamps. The results indicate that steam and dry heat sterilization do not affect retention of rubber-dam clamps.

Analysis of Variance↗
PubMed1998

Assessment of insulin sensitivity in older adults using the hyperglycemic clamp technique.

OBJECTIVE: The euglycemic glucose clamp technique is the gold standard for the measurement of insulin sensitivity in older adults, whereas the hyperglycemic glucose clamp technique is used to assess insulin release. The objective of this study was to evaluate the ability of the hyperglycemic glucose clamp technique to assess insulin sensitivity and insulin release in older people. RESEARCH DESIGN AND METHODS: Healthy older controls (n = 26, age 72 +/- 1) and older non-insulin-dependent diabetes mellitus (NIDDM) patients (n = 35, age 75 +/- 1) underwent a 2-hour hyperglycemic glucose clamp study (glucose 5.4 mM above basal) and a 3-hour euglycemic clamp study (insulin infusion rate 40 mU/m2/min). The average glucose infusion rate (last 30 minutes) of each clamp was divided by the average insulin value (last 30 minutes). This value was then divided by the average plasma glucose value to give glucose clearance per plasma insulin concentration. RESULTS: In control subjects (Eug: 0.80 +/- .05 mL/kg/min/pM; Hyper: 0.88 +/- .07 mL/kg/min/pM, P = .357) and NIDDM patients (Eug: 0.48 +/- .03 mL/kg/min/pM; Hyper: 0.42 +/- .03 mL/kg/min/pM, P = .162), glucose clearance values were similar whether calculated from the euglycemic or the hyperglycemic clamp. The correlation between glucose clearance values derived from the euglycemic and hyperglycemic clamp was excellent in normal controls (r = .76, P < .001) and patients with NIDDM (r = .71, P < .001). CONCLUSIONS: We conclude that the hyperglycemic glucose clamp technique can reliably assess both insulin release and insulin sensitivity in older people.

Aged↗
PubMed2003

Importance of obtaining independent measures of insulin secretion and insulin sensitivity during the same test: results with the Botnia clamp.

OBJECTIVE: To validate and apply a method for independent assessment of insulin secretion and insulin sensitivity (S(I)) during the same test; that is, an intravenous glucose tolerance test followed by a euglycemic-hyperinsulinemic clamp, also called the Botnia clamp. This test was then applied to nondiabetic subjects with (FH+) and without (FH-) a first-degree family history of diabetes. RESEARCH DESIGN AND METHODS: The Botnia clamp measures the first-phase insulin response (FPIR) to 0.3g/kg glucose i.v. and insulin sensitivity (M-value) from a 2-h euglycemic clamp begun 60 min after the glucose bolus. The M-value obtained during the Botnia clamp was compared with M-values obtained during a regular euglycemic clamp without prior glucose bolus. Repeated tests were performed in random order in subjects with normal and abnormal glucose tolerance. Finally, the test was applied to subjects with and without a family history of type 2 diabetes. RESULTS: S(I) and insulin secretion from this test showed a high degree of reproducibility, and the M-value obtained with the Botnia clamp correlated strongly with the M-value from a euglycemic clamp without prior glucose bolus (r = 0.953, P < 0.005). FH+ subjects showed decreased S(I) (P = 0.02), but similar FPIR, compared with FH- subjects. However, insulin secretion adjusted for the degree of insulin resistance was significantly impaired (P = 0.04). CONCLUSIONS: In conclusion, the Botnia clamp provides reliable and independent measures of S(I) and beta-cell function during the same test. As illustrated above, knowledge of the degree of S(I) is mandatory when presenting data on insulin secretion.

Diabetes Mellitus↗
PubMed1992

Experimental study of the protective effect of intermittent hepatic pedicle clamping in the rat.

The tolerance of the liver to ischaemia during intermittent clamping of the hepatic pedicle was compared with that during a continuous Pringle manoeuvre. Three groups of rats undergoing total durations of clamping of 60, 90 and 120 min were studied. A temporary peroperative portacaval shunt was used to exclude the effects of splanchnic venous stasis and allow independent study of the effects of hepatic ischaemia. In each group, three methods of portal clamping were evaluated: a continuous Pringle manoeuvre (n = 10), a 30-min intermittent clamping (n = 10) and a 15-min intermittent clamping (n = 10). The clamp release time between the periods of liver ischaemia was 5 min. Survival at day 7 and postoperative changes in liver function (transaminase enzymes, bilirubin, bromsulphthalein elimination, liver adenosine 5'-triphosphate levels) were recorded. Intermittent clamping of the pedicle was tolerated significantly better than continuous clamping. This method optimizes the ability of the liver to tolerate extended periods of ischaemia. For a given duration of ischaemia, no additional improvement could be produced by shortening the intermittent clamping period from 30 to 15 min. These data suggest that, when the Pringle manoeuvre is used, it should be applied intermittently rather than continuously.

Animals↗
PubMed2006

Selective portal clamping to minimize hepatic ischaemia-reperfusion damage and avoid accelerated outgrowth of experimental colorectal liver metastases.

BACKGROUND: Temporary vascular clamping during local ablation for colorectal liver metastases increases destruction volumes. However, it also causes ischaemia-reperfusion (IR) injury to the liver parenchyma and accelerates the outgrowth of microscopic tumour deposits. The aim of this study was to investigate the effects of selective portal clamping on hepatocellular damage and tumour growth. METHODS: Mice carrying pre-established hepatic colorectal micrometastases underwent either simultaneous clamping of both the portal vein and the hepatic artery or selective clamping of the portal vein to the median and left liver lobes for 45 min. Sham-operated mice served as controls. Hepatic injury and tumour growth were assessed over time. RESULTS: Standard inflow occlusion resulted in a rise in liver enzymes, a local inflammatory response and hepatocellular necrosis. The outgrowth of pre-established micrometastases was accelerated three- to fourfold in clamped compared with non-clamped liver lobes (27.4 versus 7.8 per cent, P < 0.010). Conversely, selective portal clamping induced minimal liver injury, tissue inflammation or hepatocellular necrosis, and completely stopped the accelerated outgrowth of micrometastases. CONCLUSION: Selective portal clamping does not induce liver tissue damage or accelerate micrometastasis outgrowth and may therefore be the preferable clamping method during local ablative treatment of hepatic metastases.

Animals↗
PubMed1980

Efficacy of the two-microelectrode voltage clamp technique in crayfish muscle.

Crayfish muscle fibres of different dimensions were voltage clamped and white noise current was injected into the fibres at various distances from the voltage clamp current electrode. The clamp current was measured and power spectral densities were calculated. This method revealed the efficacy of the voltage clamp in these fibres. In large fibres (l = 1.8-2.0 mm; diameter = 100-180 micrometer) a space clamp was achieved only for a band width delta f = 40 Hz. At a distance of 100 micrometer from the clamp electrodes delta f was 250-500 Hz. In fibres of medium size (l = 1.0-1.3 mm; diameter = 60-120 micrometer) delta f was about 80 Hz and about 800 Hz at a distance of 100 micrometer. In experiments with very small muscle fibres (l = 400-600 micrometer; diameter = 30-50 micrometer) delta f was more than 500 Hz. The improvement of the space clamp for the smaller muscle fibres resulted mainly from the reduced total membrane capacity, cm, of these fibres. The limitations of the space clamp could be derived from the impedance properties of the fibres. The band width of the space clamp correlated with the band width for which the square of the absolute impedance, /Zp/2, of the muscle fibre could be described by a simple RC-model. This correlation was demonstrated in a model circuit. Power density spectra of membrane current fluctuations were measured also. To optimize the resolution of these measurements the contribution of instrumental noise was minimized. The effects of instrumental noise are discussed.

Animals↗
PubMed1992

Chronic histologic changes after vascular clamping are not associated with altered vascular mechanics.

The mechanical properties of arteries, along with the histologic and scanning electron microscopy characteristics of the nonatherosclerotic canine arteries, were investigated six months after vascular clamping. Different vessel clamps were applied to 73 sites on the carotid and femoral arteries in five anesthetized dogs. Each clamp was applied for 30 minutes with (a) sufficient force to just occlude blood flow or (b) as tightly as the clamp could be placed. After six months the vessels were excised, filled with barium sulfate suspension, and pressurized in 25 mmHg steps up to 150 mmHg. High resolution contact radiographs were taken at each pressure. These were magnified 35x and measured. Scanning electron microscopy and conventional histology disclosed that the clamped sites exhibited serrated clamp "tracks" in the intima, intimal hyperplasia, and, in a few cases, fractured elastic lamellae. These histologic changes were seen more frequently in the femoral artery than in the carotid artery (p less than .01). The mechanical properties, as determined from radiographic measurements, demonstrated that, for all types of clamps, the luminal diameter, pressure-diameter relationship, and compliance of the clamped vessels were not significantly different from nonclamped control regions (ANOVA). These studies demonstrate that careful application of clamps to nonatherosclerotic arteries produces persistent morphologic changes, but these are not associated with altered mechanical properties of the vessel wall.

Animals↗
PubMed1994

The enhanced therapeutic efficacy of intra-arterial cis-diamminedichloroplatinum (II) chemotherapy in combination with aortic clamping on metastatic hepatic tumors in the rat.

The efficacy of intrahepatic cis-diamminedichloroplatinum (II), cisplatin, administered via the hepatic artery in combination with concomitant clamping of the abdominal aorta beneath the diaphragm against metastatic liver tumors in rats was evaluated. When 2.5 or 5 mg/kg of cisplatin was injected intra-arterially (i.a.) over 5 min, the antitumor activities in the rats with aortic clamping, evaluated by the number of tumor nodules and survival days after treatment, were found to be superior to those in the rats without aortic clamping. Side effects, evaluated in terms of glutamic oxaloacetic transaminase and glutamic pyruvic transaminase levels, changes in body weight, and the number of leukocytes, did not differ significantly among the rats with or without aortic clamping. The blood urea nitrogen levels observed in the rats with aortic clamping were lower than in those without aortic clamping. Immediately after the injection of cisplatin 5 mg/kg i.a., the platinum concentrations in the livers of rats with aortic clamping were approximately 2.1 times higher than in those without aortic clamping, and 1.4 times higher even 60 min after the injection. These increased platinum concentrations in the liver explain the enhanced antitumor activities of the rats given cisplatin with aortic clamping.

Animals↗
PubMed1981

Single electrode voltage clamp by iteration.

A technique for providing conditions of voltage clamp which differs considerably from other voltage clamp schemes has been developed. The feedback network which determines the current which will clamp the cell to the desired voltage does not operate in real time. Instead, the system uses a form of discontinuous feedback. The event to be clamped, which must be one which can be made to repeat itself without change, is elicited and allowed to run to completion without the intervention of feedback. During each repetition of the event, a current waveform is injected whose shape is based on the foregoing trials (iterations). Successive repetitions of this process develop a current waveform which ever more closely clamps the voltage to the desired value. Implementation involves a means of converting the intracellular voltage signal to digital form (a transient recorder), a means of processing the digitalized voltage signal (a digital computer), and a means of delivering the clamping current back to the preparation. The system has two advantages over other voltage clamp techniques. First, that the feedback loop is open in real time confers great stability. This advantage is exploited in the use of iterative voltage clamp in single electrode preparations. Secondly, iterative voltage clamp is essentially unlimited in the speed with which it can respond to transients. This would make the technique of interest even in preparations such as squid giant axon, where two electrodes are used and very fast responsiveness is desired.

Animals↗
PubMed1995

Use of TiNiCo shape-memory clamps in the surgical treatment of mandibular fractures.

PURPOSE: This study tested the clinical application of shape-memory clamps for fixation of mandibular fractures using transoral access. MATERIALS AND METHODS: Clamps made of Ti50Ni48.7Co1.3 alloy were used to fix mandible fractures. These clamps automatically recovered their programmed shape at body temperature. The clamps were used to treat all types of fractures occurring between the mandibular angles. Postoperative maxillomandibular fixation was not required. Clamps were removed after a period of at least 6 weeks, and tissue samples were taken for microscopic examination. RESULTS: Seventy-seven patients with mandibular fractures were treated using the shape-memory clamps. There were 19 women and 58 men, from 17 to 74 years old. Altogether 93 fractures were treated, involving 124 clamps. There were 56 cases of single fractures and 21 cases of multiple fractures. In 72 patients the treatment progressed satisfactorily; in five cases infections occurred. Histologic examination of tissue taken from 58 patients after removal of the clamps did not indicate any atypical tissue reactions or signs of disturbed cell maturation. CONCLUSIONS: The application of shape-memory clamps for surgical treatment of mandible fractures facilitates treatment while ensuring stable fixation of the bone fragments. No pathologic tissue reactions to the implants were observed in either animals or humans.

Adolescent↗
PubMed2006

Effect of pexelizumab in coronary artery bypass graft surgery with extended aortic cross-clamp time.

BACKGROUND: Prolonged cross-clamp time during cardiac surgery increases the risk of postoperative mortality and myocardial injury. This subanalysis from the pexelizumab for reduction of infarction and mortality in coronary artery bypass grafting surgery (PRIMO-CABG) trial, a phase III double-blind, placebo-controlled study of 3,099 patients undergoing on-pump coronary artery bypass graft surgery with or without valve surgery, assessed the impact of pexelizumab, an investigational C5 complement inhibitor, on postoperative outcomes after prolonged aortic cross-clamp time. METHODS: The composite endpoint of death or myocardial infarction through postoperative day 30 and death alone through days 30, 90, and 180 were examined in subpopulations of patients across different cross-clamp times. RESULTS: After prolonged cross-clamping (> or = 90 minutes), death, or myocardial infarction through day 30 and death through days 30, 90, and 180 were significantly increased in the intent-to-treat population and were even higher in patients with two or more prespecified risk factors, compared with all patients cross-clamped less than 90 minutes. Pexelizumab significantly reduced the incidence of death or myocardial infarction through day 30, and significantly reduced the incidence of mortality through day 180, in patients with two or more risk factors that required prolonged cross-clamp time. Pexelizumab also significantly reduced perioperative myocardial injury in all patients requiring prolonged cross-clamp time. CONCLUSIONS: In this retrospective, subgroup analysis, pexelizumab reduced postoperative morbidity and myocardial injury in patients with multiple risk factors who underwent prolonged cross-clamp time during coronary artery bypass surgery. The clinical benefit of pexelizumab may be related to the effect of complement inhibition in the presence of potential ischemic-reperfusion injury associated with prolonged aortic cross-clamp time.

Antibodies, Monoclonal↗