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PubMed1999

[Ischemia-reperfusion of the colon following clamping of the abdominal aorta].

Aortic cross-clamping is the cornerstone of abdominal aortic aneurysm surgery. The transient ischemia of the inferior hemisoma, and mainly of the large bowel, is then a current condition, usually well tolerated. At the time of vascular clamps removal, the ischemia-reperfusion syndrome may take place, and evolution toward multiple organ failure is an actual risk. The large bowel has a crucial role in the sequence of events causing ischemia-reperfusion syndrome, even when intestinal ischemia is not evident during aneurysmectomy. In this paper, current concepts of ischemia-reperfusion syndrome are reviewed, and the role of the colon after abdominal aortic cross-clamping for aneurysmectomy is focused. Principles of prevention of MOF from ischemia-reperfusion syndrome are pointed out.

Aortic Aneurysm, Abdominal↗
PubMed1998

[Influence of portal triad clamping on the intestine in pigs].

A pig model of liver ischemia and intestinal congestion was made by portal triad clamping (PTC) for 45 minutes to investigate the influence of PTC on intestine. The results were as follows: 1. The level of cathepsin D was increased significantly after PTC as compared with the value before clamping (P < 0.05); 2. The endotoxin and lactic acid were significantly increased after PTC comparing with those of pre-clamping (P < 0.05, P < 0.01) and the control group (P < 0.05, P < 0.01); 3. The intestinal mucosa had a significant damage (P < 0.05) after PTC. The results indicate that PTC can result in intestinal mucosal lesion and enterotoxin absorption. Therefore, the protection of intestinal functions is important in hepatic surgery and preoperative bowel preparation should be done.

Animals↗
PubMed2000

Iloprost protects the spinal cord during aortic cross-clamping in a canine model.

BACKGROUND: Surgical procedures on the thoracoabdominal part of the aorta make the spinal cord vulnerable to ischemia. Paraplegia is the most severe complication following thoracoabdominal operations. In this study, iloprost was used as an agent to decrease the severity of ischemia and reperfusion injury to the spinal cord during aortic occlusion and declamping. METHODS: Twelve adult mongrel dogs weighing 17+/-2 kg were used in this study. The animals were randomly assigned to either group I, which received saline solution (6 dogs), or group II, which received prostacyclin. Group I was referred to as the control group and group II as the iloprost group. After baseline measurements were completed, the aorta was cross-clamped for sixty minutes distal to the left subclavian artery. No pharmacologic agents were used to control blood pressure in group I. Proximal and distal mean arterial pressures (DMAP) were monitored continuously. DMAP were considered as diastolic pressure in preocclusion and reperfusion periods. Iloprost administration was started at a rate of 5 ng/kg/minute five minutes before the aortic occlusion. This dosage was increased to 25 ng/kg/minute during aortic occlusion. RESULTS: Mean proximal arterial pressure was 147+/-12 mmHg in the control group and 116+/-13 mmHg in the iloprost group at occlusion (p<0.01). Mean distal arterial pressure was 19+/-7 in the control group and 37+/-5 in the iloprost group during clamping (p<0.05). Functional outcome was evaluated according to Tarlov scores 24 hours after the study. Although none of the animals recovered completely from the control group, 4 animals from the iloprost group recovered (p<0.05). Following the neurologic assessment, animals were sacrificed and specimens were taken for the electron microscopic study. Electron microscopic changes documented that severe mitochondrial damage and vacuolisation occurred in the control group. However these changes were more subtle in the iloprost group. CONCLUSIONS: As a result of this study we concluded that iloprost infused before and during clamping of the thoracic aorta mitigates the spinal cord injury due to ischemia and reperfusion following unclamping.

Animals↗
PubMed1999

[Influence of triiodothyronine and insulin on liver adenine nucleotide levels in portal triad-clamping rats].

OBJECTIVE: To assess the influence of triiodothyronine(T3) and insulin on liver adenine nucleotide levels in portal triad-clamping rats. METHOD: A rat model of normothermic portal triad clamping was established to observe the influence of T3 and insulin on the contents of liver adenine nucleotides and survival rates. RESULT: The ATP levels and the 72 h-survival rate of T3 group were significantly higher than those of insulin group and saline group(P < 0.05). The blood glucose levels were obviously decreased and all the rats died within 6 hours postoperation in insulin group. CONCLUSIONS: T3 can improve hepatic energy metabolism after portal triad clamping and increase survival rate, whereas such effects were not found in insulin group.

Adenine Nucleotides↗
PubMedDate not supplied

Intermittent total pedicular clamping in hepatic resections in non-cirrhotic patients.

BACKGROUND/AIMS: Evaluation of intermittent total pedicular clamping in hepatic resections in non-cirrhotic patients. METHODOLOGY: A prospective study was made of 72 patients submitted to hepatic resections using intermittent total pedicular clamping. Patients were placed in 5 groups for analysis according to the duration of liver ischemia (each 20 minutes). Tolerance of liver ischemia was assessed by analysis of postoperative morbimortality and biochemical test. RESULTS: Five patients (6.9%) died during the postoperative period and sixteen patients (23.8%) developed specific complications, however, none of the variables analyzed in this study proved to be an independent risk factor for the development of postoperative morbimortality. The transaminases presented a statistically significant relationship with duration of ischemia (P < 0.002), while the late rise was influenced by postoperative mortality (P < 0.009). Prothrombin time was influenced by the duration of ischemia and by postoperative mortality (P = 0.014) but, on the other hand, the bilirubin levels only showed the influence of mortality (P < 0.002). CONCLUSIONS: Immediate postoperative liver function was better preserved in patients submitted to less than 80 minutes of clamping. The late rise of bilirubin and transaminases and the drop in prothrombin time could be considered indicators of a bad postoperative course.

Adolescent↗
PubMed2002

Aortic and mitral valve surgery on the beating heart is lowering cardiopulmonary bypass and aortic cross clamp time.

OBJECTIVE: The concept of cardiac surgery on the beating heart is acceptable rationale for the cardiac surgery in the next millenium. Beating heart (off-pump) coronary artery bypass grafting (CABG) techniques have led us to consider the possibility for performing the aortic and mitral valve surgery (mitral valve repairs and replacements - with or without CABG) on the beating heart with the technique of retrograde oxygenated coronary sinus perfusion. METHODS: We used the technique of retrograde oxygenated blood coronary sinus perfusion in 78 patients (Group All) - (36 patients were with extremely low ejection fraction (Group X) - 62% of whom were in New York Heart Association (NYHA) class 4 and 34% of whom were in NYHA class 3). The procedures for the patients were: aortic, mitral and tricuspid valve surgery, in combination with CABG in ischemic patients. CABG was done in all the cases off-pump. In addition, we performed a case match study for 37 patients with good ejection fraction (51.65 +/- 11.88) (Beating Heart Group) operated on the beating heart with most appropriate group of patients (No. 37) operated in our institutions on arrested heart (ejection fraction 51.07 +/- 12.93) (Arrested Heart Group). The case match selection criteria were: gender, left ventricular ejection fraction, atrial fibrillation, hypertension, pulmonary hypertension, and diabetes. The selected beating heart group and selected arrested heart groups were without statistically significant differences for the mentioned criteria. RESULTS: There were statistically significant differences between Beating Heart Group and Arrested Heart Group in the duration of Cardiopulmonary Bypass Time (69.35 +/- 13.52 min. versus 93.59 +/- 28.54 min.), p<0.001, and statistically significant differences in Aortic Cross Clamp Time (46.5 +/- 8.95 min. versus 61.5 +/- 18.34 min.), p<0.001. The values for Creatinin Kinase (CK) and LDH were not statistically different, however the absolute values for Beating Heart Group were lower. There was no statistical difference in complication rate for both the groups for: sternal infection, bleeding, death, atrial fibrillation, AV block and neurological complications. The total early mortality for all the patients was 5.1% (4 out of 78) - for the group X 8.3 % (3 of 36 patients). Two were in-hospital deaths. One patient with triple-vessel disease and acute mitral insufficiency on intra aortic balloon pump (IABP) had been operated on 6 days after acute myocardial infarction (AMI). The cause of the death was systemic meticillin resistant staphylococus aureus (MRSA) infection - (eight days prior to our operation, arthrodesis of the talocrural joint was performed by an orthopedic surgeon). The other death was a female patient who was operated on after previous multiple cerebrovascular infarctions (CVI) (cause of the death was CVI). In addition, one patient died one month after the operation because of prosthetic valve endocarditis (PVE) on aortic and mitral valves (silver-coated silzone aortic and mitral valves were implanted because of chronic latent asymptomatic tibial osteitis). None of these deaths were cardiac related. CONCLUSIONS: We conclude that beating heart valve surgery (any combination) with or without CABG significantly lower the cardiopulmonary bypass and aortic cross clamp time. In addition, the advantages of beating-heart surgery are 1) the perfused myocardial muscle, 2) the heart is not doing any work, 3) no reperfusion injury, 4) the possibility for ablation of atrial fibrillation on the beating heart, and 5) testing of the mitral valve repair is done in real physiologic conditions in the state of left ventricle beating tonus. The procedure could be the procedure of choice for the valve operation or combined operations (valve operation and CABG) in high-risk patients with low ejection fractions. There is no doubt that at present day in cardiac surgery exist at least two major factors for mortality and morbidity after cardiac surgery, which are operation - related, namely cardiopulmonary bypass time and its duration and aortic cross clamp time (ischemic time of myocardium). In the last few years a number of different techniques emerged in the field of cardiac surgery, which were directed toward better results in the selected high risk patients or to minimize the deleterious effects of cardiopulmonary bypass (CPB) on the overall postoperative performance [Calafiore 1996, Tasdemir 1998]. Due to the fact, that the cardiac muscle should be protected at most during the cardiac arrest, retrograde blood cardioplegia was successfully introduced [Buckberg 1990], and more - the warm cardioplegia is being used recently [Kawasuji 1997]. The natural status of the human heart is the beating status, so it is reasonable to try to perform the operations on the beating heart. This has been done recently with the MID - CAB and OP - CAB (off-pump CABG) operations [Tasdemir 1998]. The retrograde warm blood cardioplegia has therefore led us to the premise, that with retrograde oxygenated blood perfusion it would be possible to achieve the operations on the beating heart even in the open heart surgery, such as aortic and/or mitral valve surgery. All will agree that the most damaging effect of the cardioplegia is the reperfusion injury [Allen 1997], and it is obvious that with the technique of retrograde continuous oxygenated blood perfusion this effect will be canceled. In this article, we would like to show the how-to technique for the operations on the beating heart in the case of operations on the aortic valve replacement (AVR) with mitral valve repair (MVR) or replacement MVR and with/without concomitant coronary artery bypass (CABG) surgery. The tricuspid valve repair (PTV) is normally done on the beating heart and there it is realized what problems or technical difficulties may arise during procedures on the mitral valve: the walls of the ventricles are not flattened and the exposure of the mitral valve is challenging task. Furthermore, the free walls of the ventricles with interventricular septum are in the state of the tonus, so every force applied to better expose the aortic or mitral valve is not acceptable

Aortic Valve↗
PubMed2002

[A clinical study on clamp technique of intraocular lens on anterior capsule in cases with big rupture of posterior capsule of lens].

OBJECTIVE: To investigate the long-term results of the clamp technique of the posterior chamber intraocular lens (IOL) on the anterior capsule of lens in cases with big rupture of posterior capsule of lens. METHODS: The clamp technique of the posterior chamber IOL on the anterior capsule of lens were performed on 48 eyes of 48 cases with big rupture of the posterior capsule of lens following extracapsular cataract extraction for senile, traumatic, complicated and diabetic cataract. After 3-60 months follow-up, the vision acuity, position of IOL, capsular opacity and post-operative complications were investigated. RESULTS: The visual acuity of 39 eyes (81.3%) was >/= 0.5. The position of all IOL was in the optical center. The complications, such as after-cataract, retinal detachment, secondary glaucoma and persistent uveitis were not found. CONCLUSION: The clamp technique of the posterior chamber IOL on the anterior capsule of lens is convenient, safe and effectual in cases with big rupture of posterior capsule of lens.

Adult↗
PubMed1978

Membrane currents in a calcium type muscle membrane under voltage clamp.

Four ionic current components were identified in the total membrane current recorded under voltage clamp conditions from the muscle membrane of the crayfish (Astacus fluviatilis). The early inward current component is dependent on the presence of Ca2+ ions, disappears in Ca2+ free solutions and is insensitive to variaton of external Na+ ions and to tetrodotoxin. The outward current consists of at least three components, an early, a late and a slow outward current. The outward currents are sensitive to TEA and their reversal potentials differ. The early potassium current may be separated in a proportion of fibres by a hump from the later potassium current. An insufficient space clamp as a cause of the hump was excluded by comparing the size of the clamped membrane area with the distribution of large membrane clefts in the fibre. The early outward current is critically dependent on the presence of Ca2+ ions and is relatively more sensitive to TEA ions and to conditioning depolarisation than the late outward current.

Action Potentials↗
PubMedDate not supplied

[Suprarenal aortic cross-clamping and renal function].

Renal failure occurs in 1-13% of abdominal aortic reconstructions. In our survey of 81 abdominal aortic aneurysms, out of 100 abdominal aortic operations, suprarenal cross-clamping was necessary in 4 cases, with 1 transient postoperative dialysis, followed by a fully restored renal function in 19th postoperative day. Among the cases with infrarenal aortic cross-clamping, one patient died owing to colonic infarction, another patient presented progressive and persistent renal damage. From our experience, literature results and knowledge about renal physiopathology, it must be stressed that during and after abdominal aortic operations not only the manouvres of supra or infrarenal aortic clamping, but also concomitant cardiac diseases, the share of body fluids, and consequent hydroelectrolytic changes could affect the renal function. All these factors, and not only the technical aspects, should be considered with the aim of doing a correct prevention of the postoperative renal failure.

Aged↗
PubMed2005

[Brain protection with mild hypothermia during carotid artery clamping].

A 71-year-old man was scheduled for removal of a Kirchner wire malpositioned in the mediastinum, which had been placed for fixing the fractured right clavicle five months before. Anesthesia was induced and maintained with propofol, fentanyl and vecuronium. The wire was found to be penetrating the brachiocephalic artery after sternotomy. An emergency angiography performed in the operating room showed that Willis arterial circle was sufficiently developed for clamping the brachiocephalic artery. The wire was removed under clamping the brachiocephalic artery for 9 minutes, but massive bleeding from the left common carotid artery continued, then the left common carotid artery was clamped and injured region was resected and reconstructed for 68 minutes. The body temperature was reduced to 32.5-33 degree with a cooling water mattress for brain protection and prostaglandin E1 was infused for vasodilation during hypothermia. Monitoring with somatosensory evoked potential was added during anesthesia. The surgery was performed uneventfully and the patient showed no neurological sequelae postoperatively.

Aged↗
PubMed2006

Non-programmed clamping of superior vena cava. The anesthesiologist's Achilles' heel.

This case presentation focuses on the hemodynamic alterations due to acute clamping of superior vena cava (SVC) during a right pneumonectomy for lung cancer and on the alternatives for drug administration. In a 71-yr-old female patient without clinical manifestations of SVC syndrome, this large vein was clamped for 22 minutes for patch placement after sudden and unpredictable hemorrhage. The patient became acutely cyanotic and edematous in the face and upper extremities, arterial blood pressure dropped and the venous pressure in the right internal jugular vein was elevated. Drugs for managing the patient were given endobronchially and via an established right atrium line. Postoperatively, no neurologic deficit was noted. This case demonstrates the difficulties for managing patients without superior vena cava syndrome in which acute, non-programmed intra-operative SVC clamping is performed, as this is followed by systemic and brain hemodynamic deteriorations that may lead to bad outcome.

Aged↗
PubMedDate not supplied

[Coronary revascularization surgery without cross-clamping, advantages and outcomes].

The Coronary revascularization surgery has been the best option to treatment of ischemic heart disease. However, as a result of the advent of hemodynamic procedures, the complexity of the patients subject to surgery, increase importantly. For this cause the surgeons has modified their techniques and has arisen the off-pump coronary revascularization surgery. This technique cause a low inflammatory response and accordingly low organic damage to avoid the extracorporeal circulation and the "Pump exit"; nevertheless in many cases are incomplete, more complex, uncomfortable and not practicable in all patients. For this reason has appeared a procedure to allow a join between the advantages of without aortic cross-clamping and the security of the circulatory assistance to patient: The Coronary revascularization surgery without cross-clamping with circulatory assistance,and heart-beating. To determine the results of the Coronary revascularization surgery without aortic cross-clamping with circulatory assistance and heart-beating we studied 64 patients with ischemic heart disease of March of 2002 to May of 2005. In comparison with conventional surgery, the bleeding, mediastinitis, perioperative infarct to heart and cerebrovascular accident was not significant (p = 0.12-0.34) however the mortality was more low (p < 0.05) in this group (7.40%) in comparison with conventional surgery (8.79%).

Female↗
PubMed1991

[A clamp for suturing of duodenal stump].

An original clamp was used in suturing a duodenal stump after gastric resection in 77 patients. The complex relief of the blades of the clamp holds the duodenum reliably during application of the sutures and ensures their air-tightness. The trauma inflicted to the duodenum in this case is minimal. During resection of the stomach in 37 patients the author used the clamp in closure of the lesser curvature. Incompetence of the duodenal stump was not encountered.

Constriction↗
PubMed1991

Myocardial temperature management during aortic clamping for cardiac surgery. Protection, preoccupation, and perspective.

The temperature of the heart and the duration of aortic clamping are the two aspects of myocardial protection that receive the greatest amount of attention during many cardiac operations. Preoccupation with profound cardiac cooling has given rise to the development of multiple devices to keep the heart as cold as possible. This report is written to put into perspective the roles of hypothermia and aortic clamping in the overall strategy of myocardial protection. I also wish to (1) suggest that intraoperative myocardial damage is determined more by "how the heart is protected" than by "how long the aorta is clamped or how cold the heart is made," (2) question whether the benefits of deep cardiac hypothermia are sufficient to offset the monetary costs and morbidity that may result from its use, and (3) suggest that using all the measures currently available to prevent, avoid, and reverse ischemic and reperfusion damage is preferable to preoccupation with profound cardiac cooling.

Aorta↗
PubMed1991

Late arterial erosion of a Crutchfield vascular clamp presenting with transient ischemic attacks: review of treatment options.

Crutchfield clamps were once widely used for proximal carotid artery ligation in the treatment of intracranial aneurysms and cavernous sinus fistulae. Consequently, there are a number of patients being followed who were treated with this device 10 to 15 years ago. The most important complication of this treatment modality in both the early and late postoperative period is thromboembolic phenomenon presenting as transient ischemic attacks, or a frank stroke. Because of the residual patient population with this device still in place, interval reports regarding the occurrence and treatment of late complications are important. We report a patient who underwent Crutchfield clamp application for control of a cavernous sinus fistula and had done well for 20 years when he developed transient ischemic attacks (TIA). Arteriography revealed a severe stenotic lesion (greater than 90%) in the common carotid artery with a patent internal carotid artery and no evidence of the previous fistula and an ulcerated plaque. At surgery, the pressure plate of the clamp had achieved an intraluminal position. The stenotic area was resected and an end to end anastomosis performed with complete resolution of symptoms after 18 months of follow-up. In this report we review the literature for complications of this device and discuss treatment options.

Arteriovenous Fistula↗
PubMed1991

[Cardioplegic arrest and intermittent aortic clamping: comparison in coronary artery bypass graft].

427 randomized patients undergoing coronary artery bypass graft (CABG) were divided into two groups. In Group A (269 patients), myocardial protection was achieved using cardioplegic solution (Bretschneider). Group B (158 patients) was operated with intermittent aortic cross-clamping. Between both groups there was no significant difference in early postoperative mortality rates, incidence of postoperative low output syndrome, perioperative myocardial infarctions, length of ICU-stay, length of intubation, incidence of arrhythmia, and inotropic requirements. The ratio of reperfusion time divided by aortic cross-clamping time (R/C-ratio) in Group B (1.06 + 1.17) was larger than in Group A (0.49 + 0.17), which could explain this result. In Group A significantly larger incidence of postoperative arrhythmia was recognized, if reperfusion time was shorter than 20 minutes. Also in Group A, longer postoperative intubation was required with R/C-ratio under 0.60. In Group B longer intubation was needed postoperatively with aortic cross-clamping time longer than 30 minutes, reperfusion time shorter than 30 minutes, or R/C-ratio under 0.80. In conclusion, reperfusion should be continued at least for 20 minutes and if possible, for the length equivalent to R/C-ratio over 0.60 in CABG with presently widely used cardioplegic arrest.

Adult↗
PubMed1991

The effect of ibuprofen on cardiac performance during abdominal aortic cross-clamping.

Decreased cardiac output and increased plasma thromboxane have been observed during aortic cross-clamping under general anesthesia. Amelioration of these changes has been reported by preoperative administration of cyclooxygenase inhibitors, but heterogeneity in patients' intravascular volume status has confounded analysis of the drugs' effects in previous studies. We studied hemodynamic conditions in 24 volume-loaded (pulmonary capillary wedge pressure greater than 10 mm Hg) patients undergoing abdominal aortic aneurysm repair under general plus epidural anesthesia, after preoperative double-blind administration of either ibuprofen 800 mg (n = 12) or placebo (n = 12). The hemodynamic response to aortic cross-clamping was similar in both groups. Pulse and mean arterial pressure remained unchanged; cardiac index decreased after aortic cross-clamping from 2.4 +/- 0.1 (mean +/- standard error of the mean [SEM]) to 2.1 +/- 0.1 1/min/m2 in the ibuprofen group and from 2.5 +/- 0.1 to 2.3 +/- 0.2 1/min/m2 in the placebo group (p less than 0.01 versus preclamp values in both groups, multivariate analysis of variance [MANOVA]), but improved after declamping. Both left and right ventricular stroke work indexes followed a similar pattern. Plasma 6-keto prostaglandin Fl alpha (6-k-PGF1 alpha) increased transiently from a baseline level of 304 +/- 44 to 2083 +/- 698 pg/ml plasma in mixed venous blood 30 minutes after incision in the placebo group (p less than 0.05), but no other significant change in plasma 6-keto prostaglandin Fl alpha or in thromboxane B2 occurred in either group at any other time.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Blood flow velocity in the middle cerebral artery during carotid cross-clamping: loss of regulatory response to carbon dioxide partial pressure. A transcranial Doppler intraoperative study.

The CO2 reactivity of blood flow velocity in the Middle Cerebral Artery (MCA) was explored by Doppler ultrasound, in nine patients, at the time of common carotid artery cross-clamping during vascular surgery, in order to detect if a regulatory response apply during operative occlusion of common carotid artery. Transcranial Doppler was used to monitor ipsilateral MCA blood velocity during carotid surgery. MCA velocity, arterial blood pressure and pCO2 (arterial or end-tidal) were measured, during carotid cross clamping, before and after an increase in pCO2 was induced by changing respiratory rate and volumes. No relevant changes in MCA flow velocities were detected in patients with stable arterial blood pressure. In those patients showing an increase in blood pressure during the surgical procedure the MCA velocity increased accordingly. It is suggested that the cross-clamping of common carotid artery is a critical condition in which no regulatory response can be elicited: blood flow velocity tends to parallel the perfusion pressure and also CO2 reactivity is lost.

Aged↗