Splanchnic blood flow response to intraaortic balloon pump assist of hemorrhagic shock

Hemorrhagic shock results in marked changes in splanchnic arterial blood flow. We studied the effects of intraaortic balloon pump assist (IABP) upon splanchnic blood flow during sustained hemorrhagic shock and following volume resuscitation. Hemorrhagic shock was induced (mean blood pressure = 30 mm Hg) for 120 min in 20 dogs. Controls (n = 11) underwent resuscitation with shed blood and lactated Ringers solution only. In the study group (n = 9), IABP was begun after 60 min of hemorrhagic shock and continued throughout a 90-min period after resuscitation. Hemodynamic parameters were assessed and splanchnic blood flow was estimated (radioactive microsphere technique) at baseline, through 120 min of sustained hypotension, and during the resuscitation period. Splanchnic blood flow was significantly reduced in both the control and the IABP groups during the period of hemorrhagic shock. Interestingly, the IABP group was found to have a return to preshock splanchnic viscera perfusion without the hyperemic reperfusion phenomenon seen in control animals resuscitated with shed blood and Ringers lactate alone. IABP assist of hemorrhagic shock appears to improve vasomotor control of splanchnic blood flow in this experimental preparation of shock. This may result in less reperfusion injury to the splanchnic viscera during the resuscitation of severe hemorrhagic shock.     

Femoral artery infection complicating intraaortic balloon pumping

Infection of the femoral artery (endarteritis) complicating intraaortic balloon pumping has not been reported. Most reports of complications with this pump have not emphasized wound infection. Whether the balloon is inserted by open or percutaneous technique, infection remains a problem. During the past 7 years, 32 of 50 patients (64 percent) who had intraaortic balloon pump insertion survived balloon removal. In four patients, wound infection of the groin developed with involvement of the femoral artery. Sepsis was due to P. aeruginosa in three patients and E. cloacae in one. All patients required variable degrees of resection of the infected femoral artery wall. One had successful arterial reconstruction with vein patch angioplasty alone after debridement of the vessel wall. In a second patient, resection of the common femoral artery with interposition of a saphenous vein that had been reconstructed to enhance its diameter to that of the femoral artery was accomplished. Dehiscence of a vein patch angioplasty occurred in the remaining two patients with resultant hemorrhage. Further resection of the femoral artery was required with femoro-femoral saphenous vein grafting in one patient and iliofemoral vein grafting in another. Tissue coverage of the reconstructed vessel was best accomplished using a tensor fascis lata myocutaneous flap. All patients survived the infection without amputation.     

Femoral artery pseudoaneurysm by intraaortic balloon pumping

Femoral artery pseudoaneurysm is one of multiple vascular complications with intra aortic balloon pumping (IABP). In a series of 815 cases, the incidence of pseudoaneurysm formation was 0.61 percent. Six patients with this complication who underwent successful surgical repair were reviewed. Three cases in our series were obviously due to the unsuitable technique of balloon removal. Especially a patient who underwent IABP insertion after exposure of the femoral artery should undergo open removal of the balloon with reconstruction of the femoral artery. In conclusion, femoral artery pseudoaneurysms are expected to diminish by the appropriate technique of balloon removal.     

Axillary artery insertion of an intraaortic balloon pump

We describe a technique for insertion of an intraaortic balloon pump through the axillary artery. This approach is useful in patients requiring intraaortic balloon pump support before cardiac transplantation in that it dramatically increases patient mobility while awaiting a donor heart.     

The impact of in-situ balloon occlusion of the renal artery and hypothermic perfusion on renal blood flow

Summary Unilateral renal blood flow was evaluated in-situ in 13 dogs by cineangiodensitometry and microsphere distribution studies before and after intermittent balloon occlusion with and without hypothermic perfusion of one kidney. The contralateral kidney served as control. No significant difference in renal blood flow and vascular resistance was noted before, and 5, 30 and 60 minutes after unilateral intra-arterial manipulation. Compartmental flow distribution studies in 5 dogs revealed no evidence of alteration of intra-renal haemodynamics. In a clinical pilot study, unilateral renal blood flow measured by cineangiodensitometry showed no change of clinical significance 5 and 60 minutes after intraluminal balloon occlusion of the renal artery for 60 seconds.     

Augmentation and redistribution of myocardial blood flow during acute ischemia by intraaortic balloon pumping

Regional coronary blood flow (CBF) in the acutely ischemic, normotensive ventricle was evaluated using radionuclide-labeled microspheres. Intraaortic balloon pumping (IABP) significantly increased CBF to myocardium made ischemic by either total or partial coronary artery occlusion. Both subendocardial and myocardial CBF in the ischemic area were increased by IABP, associated with a slight but not significant decrease in CBF to normally perfused areas of myocardium. The heart in this setting appears to autoregulate local CBF in response to IABP.     

Paraplegia following intraaortic balloon assistance.

In a patient receiving intraaortic balloon counterpulsation following myocardial revascularization, paraplegia developed two days post-operatively. Postmortem examination demonstrated a dissecting hematoma of the thoracic aorta and spinal cord infarction. The neurological deficit is thought to be due to embarrassment of spinal cord blood supply, and mechanisms of injury are discussed.     

Endothelium-derived nitric oxide enhances the effect of intraaortic balloon pumping on diastolic coronary flow.

BACKGROUND: High shear rate with pulsation is one of the major stimuli for the release of endothelium-derived nitric oxide leading to coronary arteriolar dilation. Intraaortic balloon pumping mechanically enhances shear rate and diastolic-to-systolic flow oscillation. We aimed to evaluate whether or not coronary blood flow augmentation during intraaortic balloon pumping is mediated by coronary arteriolar dilation through endothelium-derived nitric oxide release. METHODS: Using a charge-coupled device intravital videomicroscope, we observed epicardial coronary arterioles (40 to 220 microm in diameter) in anesthetized open-chest dogs (n = 10) during 2:1 mode of intraaortic balloon pumping. Endothelium-derived nitric oxide-mediated vasodilatory effects of intraaortic balloon pumping were evaluated by comparing end-diastolic arteriolar diameters between the coupled beats of on and off intraaortic balloon pumping before and after intracoronary endothelium-derived nitric oxide synthesis inhibition with Nomega-nitro-L-arginine (L-NNA, 2 micromol/min) administration. RESULTS: Intraaortic balloon pumping increased coronary arteriolar diameters and coronary blood flow by 11.4%+/-1.8% (p < 0.0001) and 33.4%+/-4.1% (p < 0.001), respectively. Vasodilation was greater in small arterioles (<110 microm; 15.4%+/-2.2%) than in large arterioles (> or =110 microm; 4.2%+/-1.2%, p < 0.0001). L-NNA attenuated the intraaortic balloon pumping-induced vasodilation and augmentation of coronary blood flow to 4.6%+/-1.0% (p < 0.001) and to 20.8%+/-2.1%, (p < 0.05), respectively. Attenuation of vasodilatory effect by L-NNA was observed mainly in small arterioles (from 15.4%+/-2.2% to 5.9%+/-1.2%). CONCLUSIONS: Intraaortic balloon pumping augmented coronary blood flow by dilating coronary arterioles in diastole, more significantly in small arterioles than in large arterioles. Endothelium-derived nitric oxide inhibition markedly attenuated these effects. We conclude that, in a canine model, endothelium-derived nitric oxide contributes to mechanical enhancement of the coronary blood flow with diastolic arteriolar vasodilation during intraaortic balloon pumping.     

Percutaneous treatment of acute iliac artery injury after intraaortic balloon counterpulsation

We report on a novel approach to correcting iliac artery occlusions caused by aortic counterpulsation. Two patients who had leg ischemia after retrieval of an intraaortic balloon pump underwent angiograms that showed occlusion of the right external iliac artery because of dissection (one case) or thrombosis (one case). Percutaneous self-expandable stents were implanted in the occluded vessels, and they fully restored normal iliac patency with no complications and satisfactory midterm follow-up results. We conclude that iliac artery occlusion induced by aortic counterpulsation can be safely treated by implanting self-expandable stents in cases of acute iatrogenic dissection. (J Vasc Surg 1996;24:279-83.)     

Elective intraaortic balloon counterpulsation in high-risk off-pump coronary artery bypass grafting

The beneficial effects of intraaortic balloon pump (IABP) in CABG with cardiopulmonary bypass (CPB) have been reported. However, the benefits of insertion of IABP electively in high-risk off-pump coronary artery bypass grafting (OPCAB) have not been established. Six hundred and twenty-five patients who underwent OPCAB form the study group. High-risk patients fulfilling two or more of the following: left main stem stenosis >70%, unstable angina, and poor left ventricular function, who had elective insertion of IABP preoperatively by the open technique (group I; n = 20) were compared with a similar high-risk group that did not (group II; n = 25). There were no significant differences in risk factors between the two groups (Euroscore 5.68). The mean number of grafts was similar. Postoperatively, there were no significant differences in the need for inotropes, duration of ventilation, arrhythmias, cerebrovascular, gastrointestinal, and infective complications (p = NS). There were no IABP-related complications. Acute renal failure requiring hemofiltration was higher in group II (n = 5; p < 0.05). Four patients (16%) in group II required postoperative IABP. Although intensive care stay was longer in group I (27.6 +/- 15.3 vs. 18.6 +/- 9.1 hours; p < 0.05), patients in group I were discharged earlier from hospital. There was no difference in mortality between the two groups (n = 1 in each group). In high-risk patients undergoing OPCAB, routine preoperative insertion of IABP electively reduces the incidence of acute renal failure. In addition it avoids the need for emergency insertion postoperatively and may result in earlier discharge.     

Elective intraaortic balloon counterpulsation for high-risk off-pump coronary artery bypass operations

BACKGROUND: Dislocations of the heart required for exposure and construction of distal anastomoses often produce hemodynamic instability when performing coronary artery revascularization without using cardiopulmonary perfusion (OPCAB). We report our early experience with elective intraaortic balloon counterpulsation (IABP) to enable and facilitate selected high-risk patients to undergo OPCAB. METHODS: Sixteen high-risk patients undergoing multivessel OPCAB using elective IABP are reported. The patients were believed to be at increased risk because of the presence of severe proximal multivessel coronary artery obstruction, ventricular dysfunction, recent acute myocardial infarction, cardiomegaly-cardiomyopathy, and documented cerebral vascular disease. The presence of significant comorbid disease also made the avoidance of cardiopulmonary bypass desirable, if at all possible, in all patients. RESULTS: The IABP appeared to facilitate the intraoperative management of our series of patients. This was evidenced by improved hemodynamic stability and virtual elimination of the need for inotropic support during the dislocations of the heart needed for exposure and construction of distal anastomoses. There were no complications related to use of IABP. There was one death. CONCLUSIONS: We believe this strategy to use IABP selectively can allow surgeons to safely extend the benefits of OPCAB procedures to high-risk patients and avoid dangerous hemodynamic instability that otherwise, often occurs.     

Origins of intraaortic balloon pumping

In 1968, the Journal of the American Medical Association published a paper on the "Initial clinical experience with intraaortic balloon pumping in cardiogenic shock," which gave the results of the first clinical use of the procedure developed in our laboratory. For more than 2 years, our group was the only one using intraaortic balloon pumping clinically. Later, intraaortic balloon pumping was used by others, and despite poor clinical salvage, the hemodynamic benefit was demonstrated convincingly. At the present time, approximately 70,000 balloon pump procedures are performed annually.     

Removal of intraaortic balloon without vascular complications.

A technique for inserting and removing the intraaortic balloon pump without vascular complications is descirbed. Prevention of clot formation at the graft-arterial junction, preservation of collateral circulation by insertion in the common femoral artery, removal of potentially infected graft material, and enlargement of the common femoral artery by patch angioplasty are important factors.     

Influence of biopump with and without intraaortic balloon on the coronary and carotid flow

BACKGROUND: The objective of this study was to evaluate the influence of biopump used for left ventricular assistance on the coronary and carotid flows in dogs with normal heart. The efficacy of the simultaneous use of an intraaortic balloon pump to compensate the possible deleterious effects of the circulatory assistance with continuous flow was also analyzed. METHODS: Fifteen dogs were studied. The hemodynamic evaluation included serial measurements of the classic parameters. Carotid and coronary blood flows were obtained by electromagnetic transducers. RESULTS: The hemodynamic evaluation did not show significant statistical changes. The use of circulatory-isolated assistance with biopump shows reduction (24.6% +/- 6.1%) in coronary flow, in relation to the control situation and the concomitant use of biopump and intraaortic balloon pump showed similar coronary flow. Regarding carotid flow, a similar trend was observed in relation to the positive influence of the pulsatile flow with an intraaortic balloon pump without statistical significance (p = 0.0582). CONCLUSIONS: The biopump reduces the coronary flow in dogs. The use of intraaortic balloon pump with the biopump increases the coronary flow significantly, reaching similar values to those observed without the circulatory assistance.     

New sequential synchronized driving system of intraaortic balloon pumping and left ventricular assist device: influence on endocardial viability ratio and renal blood flow in their combination

Intraaortic balloon pumping (IABP) and left ventricular assist devices (LVAD) have shown remarkable progress individually, but how to combine them is still unknown. A new sequential synchronized driving system was developed to control concomitant use of IABP and LVAD, and then its hemodynamic effectiveness was evaluated in swine, especially on endocardial viability ratio (EVR) and renal blood flow. This system (pulsatile bypass pump-delay divide system, PBP-DDS) made it possible to change the driving phase of IABP and LVAD easily. In 12 swine, IABP and LVAD were set up, and these devices were driven in the following 5 modes with the PBP-DDS: mode I, IABP alone; mode II, LVAD alone; mode III, IABP + LVAD (same timing); mode IV, IABP (early diastole) + LVAD (late diastole); and mode V, LVAD (early diastole) + IABP (late diastole). EVR was increased more markedly by combined use of both IABP and LVAD (modes III, IV, and V) than by individual drive, but there was no significant difference among these modes. On the other hand, renal blood flow was decreased so dramatically by the same timing optimal counterpulsation method of mode III that it was thought to be harmful for renal function. But, the delay divide combination method of modes IV and V resulted in no change in the renal circulation. So, it was concluded that this delay divide combination mode appeared to be a more promising support to both failed heart and renal circulation.     

Vascular complications of intraaortic balloon counterpulsation

Between February 1973 and December 1986, 4,787 patients underwent open heart surgery at Samuel Merritt Hospital. Retrospective analysis revealed 395 (8 percent) consecutive patients who required hemodynamic support with the intraaortic balloon pump. Thirty percent of the patients had preoperative placement, 56 percent needed the balloon in order to wean from cardiopulmonary bypass, and 14 percent required placement in the postoperative period. The intraaortic balloon pump was instituted with multiple techniques and insertion sites. Three hundred eighty-three balloon catheters (96 percent) were inserted through the groin by surgical cutdown or a percutaneous approach. The remaining devices were inserted through the aortic arch. A 12 F. catheter was utilized in 239 patients (61 percent) and a smaller 10.5 F. catheter was placed in 156 patients (39 percent). The hospital mortality rate was 47 percent. Seventy-two of the 395 patients (24 percent) sustained vascular complications related to balloon use. Major complications occurred in 43 patients. Twenty-nine patients sustained minor complications that resolved spontaneously with balloon removal. Risk factors evaluated included patient gender, New York Heart Association class, catheter size, method of introduction, duration of counterpulsation, and presence of symptomatic peripheral vascular disease. Since percutaneous placement was associated with a significant decrease in complications, we concluded that use of the smaller 10.5 F. catheter placed percutaneously is the safest means of employing the intraaortic balloon pump. A monitoring line is placed percutaneously through the femoral artery in high-risk patients before operation. This allows easier access for intraaortic balloon pump placement in hypotensive patients. The presence of a clinical history of peripheral vascular disease was also a highly significant risk factor for vascular complications. Other risk factors increasing the likelihood of vascular compromise included catheter size and duration of counterpulsation.     

Reinsertion predictors of intraaortic balloon pumps

The reinsertion rate of intraaortic balloon pumps (IABP) has not been clearly reported. We evaluated the use of left-ventricular ejection fraction (LVEF), fractional shortening (FS), and cardiac index (CI) values to asses cardiac performance as weaning criteria for IABP in a prospective study performed in 100 patients who required IABP. Patients were randomly divided into 2 groups of 50 patients. In group 1, classical hemodynamic criteria were considered as weaning criteria of IABP. In this group, IABPs were removed when measurements of general hemodynamic criteria were established to be in normal ranges. In group 2, LVEF, FS, and CI values reflecting cardiac performance were used to monitor patients under IABP support, and IABPs were removed when LVEF, FS, and CI values reached >30%, >20%, and >2.4 L/min per m2, respectively. Reinsertion of IABP was necessary in 13 patients in group 1 and in 9 patients in group 2 (P = .48). Vascular complications were the main cause of reinsertion of IABP in 7 and 9 patients in group 1 and group 2, respectively (P = .59). Nine patients died in group 1 and 2 in group 2 (P = .025). In group 1, death due to myocardial dysfunction occurred in 8 of 13 patients (62%) who had required reinsertion of IABP; 6 of these patients required reinsertion of IABP because of hemodynamic deterioration, whereas no patients in group 2 required reinsertion of IABP because of hemodynamic deterioration (P = .027). LVEF, FS, and CI values higher than 30% (P = .008), 20% (P = .005), and 2.4 L/min per m2 (P = .013), respectively, showed good outcomes in regard to avoiding reinsertion of IABP, indicating that these measurements were significant predictors for reinsertion of IABP.