Visceral arterial compromise during intra-aortic balloon counterpulsation therapy

Complications associated with intra-aortic balloon pump treatment in critically ill patients: A systematic review

BACKGROUND

In recent decades, intra-aortic balloon pump (IABP) technology has made significant progress (sheathless insertion technique, different balloon diameters, percutaneous technique and fibre optic IABP) in reducing complications and increasing patient support. Nonetheless, IABP-related complications are still frequent and are associated with a poor prognosis.

AIM

The aim of this systematic review was to identify complications associated with IABP treatment in critically ill patients with a compromised cardiac function.

STUDY DESIGN

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines based on searches in CINAHL (EBSCO), Medline and Embase (Ovid) from January 2012 to April 2023. Quantitative studies were included if they reported as their primary outcome(s) complications of IABP in adult patients because of cardiovascular conditions and were published in English, Norwegian, Swedish or Danish. Study selection, methodological quality assessment and data extraction were performed independently by two authors. The results were synthesized narratively.

RESULTS

A total of nine studies were included in the review, most of which were retrospective (eight of nine). Bleeding was the most frequently occurring complication, followed by limb ischaemia, stroke, infection, IABP malfunction, haematoma and other vascular complications. In addition, a correlation between IABP duration and vascular complications was found in three out of nine studies. Lastly, the incidence rate of stroke was higher in patients with axillary IABP than in those with femoral IABP.

CONCLUSIONS

This systematic review revealed that bleeding and limb ischaemia were the two most frequent complications associated with IABP therapy. We identified a correlation between (a) IABP support time and the development of vascular complications and (b) stroke and implantation of IABP catheter in the axillary artery. Further studies are needed to explore these findings directly.

RELEVANCE TO CLINICAL PRACTICE

Increasing critical care nurses' knowledge regarding complications related to IABP support could lead to early identification, potentially lowering the incidence rate of complications.

Role of Mechanical Circulatory Support in Complex High-Risk and Indicated Percutaneous Coronary Intervention: Current Indications, Device Options, and Potential Complications

Improved expertise and technological advancements have enabled the safe and effective performance of complex and high-risk-indicated percutaneous coronary intervention (CHIP) in patients previously considered inoperable or high-risk. Mechanical circulatory support (MCS) devices play a crucial role in stabilizing hemodynamics during percutaneous coronary intervention (PCI) -related ischemia, thereby reducing the risk of major adverse events and achieving a more complete revascularization. However, the use of MCS devices in protected PCI is not without risks, including peri-procedural myocardial infarction (MI), bleeding, and access-related complications. Despite numerous observational studies, there is a significant lack of randomized clinical trials comparing different MCS devices in various CHIP scenarios and evaluating their long-term safety and efficacy profiles. This review aims to summarize the current evidence regarding the benefits of MCS devices during CHIPs, offer a practical guide for selecting appropriate devices based on clinical scenarios, and highlight the unanswered questions that future trials need to address.

Impact of right ventricular dysfunction on outcomes in patients requiring intra-aortic balloon pump placement: A retrospective nationwide analysis (2016-2020)

Right ventricular dysfunction (RVD) continues to be a significant contributor to both mortality and morbidity, posing a significant challenge in the management of patients undergoing evaluation for mechanical circulatory support (MCS). Currently, there is a paucity of data regarding outcomes in this subset of patients. We analyzed the National Inpatient Sample database (NIS) to identify adult hospitalizations who underwent intra-aortic balloon pump (IABP) placement with or without co-existence of RVD. Multivariate logistic regression, and linear regression analyses were used to compare outcomes, and adjust for possible confounders. Out of 126,985 hospitalizations who underwent IABP placement, 1,475 (1.2%) had RVD. Patients with RVD who received an IABP had higher adjusted odds of inpatient mortality (Adjusted odds ratio [aOR]: 2.33, 95% confidence interval [CI]: 1.7-3.2, p<0.001) than those without co-existing RVD. Hospitalized patients who underwent IABP placement with RVD had higher adjusted odds of worse hospitalization outcomes in general. Conducting additional prospective studies and clinical trials with an emphasis on further subcategorization of patients with RVD is crucial for determining optimal management strategies for these patients.

Radiology of Intra-Aortic Balloon Pump Catheters

Radiographs play an important role in ascertaining appropriate placement of the intra-aortic balloon pump catheter. This imaging essay highlights correct and incorrect positioning of these catheters, with emphasis on the variability of radiopaque markers used with different catheter models and on axillary versus femoral catheter placement routes. Keywords: Conventional Radiography, CT, Percutaneous, Cardiac, Vascular, Aorta, Anatomy, Cardiac Assist Devices, Catheters © RSNA, 2022.

Aortic flow below and visceral circulation during aortic counterpulsation: Evaluation of an in vitro model

INTRODUCTION

This study aimed to test a computer-driven cardiovascular model for the evaluation of the visceral flow during intra-aortic balloon pump (IABP) assistance.

METHODS

The model includes a systemic and pulmonary circulation as well as a heart contraction model. The straight polyurethane tube aorta had a single visceral while four windkessel components mimicked resistance compliance of the brachiocephalic, renal and sub-mesenteric, pulmonary, and systemic circulation. Twelve flow probes were placed in the circuit to measure pressures and flows with the IABP on and off.

RESULTS

With the balloon off, the meantime to reach the steady state was 48 ± 16 s; with the balloon on, this figure was 178 ± 20 s. The stability of pressure and flow signals was obtained after 72 ± 11 min. The number of cycles of stability of the system was 93 [86-103]. Measurements were reliable either with samples of 10 or 20 beats. Bland Altman method demonstrated the reliability of measurements. Finally, all measurements were comparable to published in vivo data.

CONCLUSION

The presented mock circulation was reliable and gave values with high accuracy both at baseline and during mechanical assistance. This system allows evaluation of the mesenteric flow during IABP, under different clinical/hemodynamic conditions. Nonetheless, its translational potential needs to be further evaluated.

Comparative Outcome Analysis of N-Butyl Cyanoacrylate Embolization of the False Lumen Versus Thoracic Endovascular Aortic Repair in Aortic Dissection

PURPOSE

To evaluate the feasibility, safety, and effectiveness of N-butyl cyanoacrylate (NBCA) embolization for the treatment of aortic dissection.

MATERIALS AND METHODS

In this single-center retrospective study conducted from February 2003 to June 2019, NBCA embolization of an aortic false lumen was attempted in 12 patients (median age, 59 y; range, 41-68 y) and thoracic endovascular aortic repair (TEVAR) was performed in 53 patients (median age, 59 y; range, 37-70 y) for aortic dissection with one or more indications of persisting pain, malperfusion, rupture or impending rupture, maximal aortic diameter ≥ 55 mm, and/or rapid aortic enlargement. The main exclusion criterion for embolization was the presence of fast blood flow in the aortic false lumen on aortography. The efficacy of NBCA embolization and TEVAR was compared by evaluating technical and clinical outcomes, repeat intervention-free survival (RFS), and overall survival (OS).

RESULTS

Technical success was achieved in 11 of the 12 patients treated with NBCA embolization (91.7%), and clinical success was achieved in 9 of these 11 (81.8%). No significant difference was found between embolization and TEVAR in clinical success rates (embolization, 81.8%; TEVAR, 84.9%; P = .409) or procedure-related complications (embolization, 1 patient [8.3%]; TEVAR, 4 patients [7.5%]; P = .701). In addition, embolization showed comparable 5-y RFS (embolization, 82.5% ± 9.3; TEVAR, 85.5% ± 4.8; P = .641) and 5-y OS (embolization, 100%; TEVAR, 95.4% ± 3.2; P = .744) rates to TEVAR.

CONCLUSIONS

NBCA embolization of the false lumen in aortic dissection seems to be a safe and effective treatment modality for the closure of false lumen in selected patients.

Risk Factors Associated with In-Hospital Mortality for Patients with Acute Abdomen After Cardiac Surgery

OBJECTIVES

Management of acute abdomen (AA) differs due to the heterogeneity of underlying pathophysiology. Complications of AA and its overall outcome after cardiac surgery are known to be associated with poor results. The aim of this retrospective analysis was to evaluate risk factors for AA in patients undergoing cardiac surgery.

METHODS

Between December 2011 and December 2014, a total of 131 patients with AA after cardiac surgery were identified and retrospectively analyzed using our institutional database. Statistical analysis of risk factors concerning in-hospital mortality of mentioned patient cohort was performed using IBM SPSS Statistics.

RESULTS

Overall in-hospital mortality was 54.2% (71/131). Analyzing in-hospital non-survivors (NS) versus in-hospital survivors (S) peripheral artery disease (28.2% vs. 11.7%; p = 0.03), the need for assist device therapy (33.8% vs. 16.7%; p = 0.03) and the requirement of hemodialysis (67.6% vs. 23.3%; p < 0.01) were significantly higher in NS. Furthermore, lactic acid values at onset of symptoms were shown to be significantly higher in NS (5.7 ± 5.7 mmol/L vs. 2.8 ± 2.9 mmol/L; p < 0.01). Assured diagnosis of mesenterial ischemia was strongly associated with worse outcome (odds ratio 10.800, 95% confidence interval 2.003-58.224; p = 0.006).

CONCLUSION

In conclusion, in critically ill patients after performed cardiac surgery peripheral vascular disease, need for supportive hemodynamic assist device systems and occurrence of renal failure are risk factors associated with worsen outcome. Additionally, rise of lactic acid could potentially be associated with onset of intestinal malperfusion and should be taken into account in therapeutic decisions preventing fatal mesenterial ischemia.

Preoperative Intra-Aortic Balloon Pumps in Cardiac Surgery: A Propensity Score Analysis

INTRODUCTION

The role of intra-aortic balloon pumps (IABP) in high-risk patients undergoing coronary artery bypass graft (CABG) surgery remains controversial. We report the 5-year experience from a new Australian centre.

METHODS

We retrospectively analysed 690 patients undergoing urgent isolated CABG surgery at a Western Australian tertiary centre from February 2015 to May 2020. De-identified data was obtained from the Australia & New Zealand Society of Cardiothoracic Surgeons database. Patients were stratified according to preoperative IABP use. A propensity score was created for the probability of IABP use and a propensity adjusted analysis was performed using logistic regression. The primary outcome was 30-day mortality. Secondary outcomes were postoperative inhospital outcomes.

RESULTS

Preoperative IABP was used in 78 patients (11.3%). After propensity score adjustment, in a subgroup of patients with reduced ejection fraction or left main disease, 30-day mortality (7.0% vs 2.0%, OR 6.03, 95% CI 1.89-19.28, p=0.002) was significantly higher in the IABP group. Red blood cell transfusions (19.7% vs 12.6%, OR 1.86, 95% CI 1.02-3.35, p=0.039), prolonged inotrope use (78.9% vs 50.9%, OR 6.11, 95% CI 2.77-13.48, p<0.001), prolonged invasive ventilation (28.2% vs 3.4%, OR 20.2, 95% CI 8.24-49.74, p<0.001), mesenteric ischaemia (2.8% vs 0%, OR 4.52, 95% CI 1.15-17.77, p=0.031) and multisystem organ failure (1.3% vs 0.7%, OR 25.68, 95% CI 2.55-258.34, p=0.006) were significantly higher in the IABP group.

CONCLUSION

In patients undergoing isolated CABG surgery, preoperative IABP use was associated with increased 30-day mortality and adverse outcomes. Large randomised controlled trials are required to confirm our findings.

Intra-aortic balloon pump: Looking at the other side

Intra‐aortic balloon pump has been the most commonly employed cardiac assist device in the past, although, in recent years, its use in cardiogenic shock has been questioned. The pathophysiology of the proximal part of the balloon has been well studied, whereas, hemodynamics and flow below the distal portion of the balloon have not been fully understood yet. The distal flow contains a three‐wave flow pattern during diastolic balloon expansion: a flow reduction in early diastole, a backflow in mid‐diastole followed by a tele‐diastolic flow. More research on this topic is warranted to better understand the physics of the distal part of the balloon and its interaction with the three components of the local regulatory system: intrinsic (local metabolic and myogenic), extrinsic (autonomic nervous system), and humoral (local or circulating vasoactive substances). These new insights will be a guide for new balloon designs that will allow enhanced performance and improved outcomes.

Patient Selection for Protected Percutaneous Coronary Intervention: Who Benefits the Most?

The evolution of percutaneous coronary intervention (PCI) enables a complete revascularization of complex coronary lesions. However, simultaneously, patients are presenting nowadays with higher rates of comorbidities, which may lead to a lower physiologic tolerance for complex PCI. To avoid hemodynamic instability during PCI and achieve safe complete revascularization, protected PCI using mechanical circulatory support devices has been developed. However, which patients would benefit from the protected PCI is still in debate. Hence, this review provides practical approaches for the selection of patients by outlining current clinical data assessing utility of protected PCI in high-risk patients.

Complications associated with mechanical circulatory support

There has been a significant increase in the utilisation of mechanical circulatory support (MCS) devices for the management of cardiogenic shock over recent years, with new devices being developed and introduced with the aim of improving outcomes for this group of patients. MCS devices may be used as a bridge to recovery or transplantation or intended as a destination therapy. Although these devices are not without their complications, good outcomes are achieved, but not without risk of significant complications. In this article, the complications of MCS devices have been reviewed, including the intra-aortic balloon pump (IABP), Impella, TandemHeart, extracorporeal membrane oxygenation (ECMO) and ventricular assist devices (VAD)—temporary and durable.

Superior mesenteric flow pattern during counterpulsation: is simply a shorter balloon the solution for visceral hypoperfusion?

OBJECTIVES

We studied the flow pattern in the superior mesenteric artery (SMA) during intra-aortic balloon pump support, comparing 2 intra-aortic balloons of 2 different lengths.

METHODS

Sixteen Landrace pigs (mean weight 84.0 kg ± 6.0) were used in this study. The animals were randomly assigned to 2 groups: group 1 received an 8-Fr, 40-ml standard balloon; group 2 received an 8-Fr, 40-ml short balloon. SMA flow was measured during early, mid- and telediastole.

RESULTS

The standard balloon led to a reduction in SMA flow in early diastole (P < 0.001), a negative flow in mid-diastole (P < 0.001) and a reincrease in telediastole (P < 0.001). In contrast, in early diastole a significant reduction was observed with the short balloon (P < 0.001), followed by another drop in mid-diastole (P < 0.001), without reaching negative values and by a telediastolic increase (P < 0.001). SMA flows were comparable between balloons during early diastole (P = 0.66), whereas they were higher with the short balloon during mid (P < 0.001) and telediastole (P = 0.02). Overall, the diastolic area was significantly larger when the short balloon was used (P < 0.001). Finally, during counterpulsation, mesenteric resistances increased significantly (P < 0.001), although, with the short balloon, they were lower than with the standard balloon (P = 0.01).

CONCLUSIONS

Despite better overall mean mesenteric diastolic flow, the short balloon leads to early- and mid-diastolic flow reduction, although to a lesser extent than the standard intra-aortic balloon pump balloon. Our data are a call for improvement in the design of the short balloon.

Ultrasound-guided insertion of intra-aortic balloon counterpulsation in intensive care: description of the technique

Intra-aortic balloon counterpulsation (IAoBC) is a mechanical circulatory support device that has been used for more than 50 years, mainly for cardiogenic shock. Although its effect on mortality is controversial, IAoBC is still used in a wide variety of pre- and postoperative clinical settings in cardiac surgery centers. IAoBC has a complication rate of approximately 30%, mostly associated with problems during insertion and malpositioning. Thus, an insertion technique based on the use of ultrasound at the patient's bedside in the intensive care unit (ICU) is proposed.

Concomitant abdominal exploration with durable left ventricular assist device implantation

A 45-year-old male presented in decompensated heart failure from nonischemic cardiomyopathy and was implanted with a right transaxillary intra-aortic balloon pump. He was listed for heart transplantation but after 9 days, he developed abdominal pain with evidence of embolization on computed tomography scan despite a well-positioned balloon pump. He underwent concomitant abdominal exploration with small bowel resection and durable left ventricular assist device implantation. He recovered well and was discharged home. This case highlights the challenges of decision-making in the current era where intra-aortic balloon pumps are being utilized more frequently as a bridge to heart transplantation.

Utilization of Percutaneous Mechanical Circulatory Support Devices in Cardiogenic Shock Complicating Acute Myocardial Infarction and High-Risk Percutaneous Coronary Interventions

Given the tremendous progress in interventional cardiology over the last decade, a growing number of older patients, who have more comorbidities and more complex coronary artery disease, are being considered for technically challenging and high-risk percutaneous coronary interventions (PCI). The success of performing such complex PCI is increasingly dependent on the availability and improvement of mechanical circulatory support (MCS) devices, which aim to provide hemodynamic support and left ventricular (LV) unloading to enable safe and successful coronary revascularization. MCS as an adjunct to high-risk PCI may, therefore, be an important component for improvement in clinical outcomes. MCS devices in this setting can be used for two main clinical conditions: patients who present with cardiogenic shock complicating acute myocardial infarction (AMI) and those undergoing technically complex and high-risk PCI without having overt cardiogenic shock. The current article reviews the advancement in the use of various devices in both AMI complicated by cardiogenic shock and complex high-risk PCI, highlights the available hemodynamic and clinical data associated with the use of MCS devices, and presents suggestive management strategies focusing on appropriate patient selection and optimal timing and support to potentially increase the clinical benefit from utilizing these devices during PCI in this high-risk group of patients.

Superior mesenteric and renal flow patterns during intra-aortic counterpulsation

NEW FINDINGS

What is the central question of this study? Visceral ischaemia is one of the most feared complications during use of an intra-aortic balloon pump. Using an animal model, we measured the flows at the abdominal level directly and examined flow patterns to enable investigation of flow patterns during the use of the intra-aortic balloon pump. What is the main finding and its importance? We show that there is a significant balloon-related reduction in superior mesenteric flow in both early and mid-diastole.

ABSTRACT

A number of previous studies have shown that blood flow in the visceral arteries is altered during intra-aortic balloon pump (IABP) treatment. We used a porcine model to analyse the pattern of blood flow into the visceral arteries during IABP use. For this purpose, we measured the superior mesenteric, right renal and left renal flows before and during IABP support, using surgically placed flowmeters surrounding these visceral arteries. The superior mesenteric flow significantly decreased in early diastole (P < 0.001) and in mid-diastole (P = 0.003 versus early diastole), whereas in late diastole it increased again (P < 0.001 versus mid-diastole). During systole, the flow was not significantly increased compared with late diastole (P = 0.51), but it was significantly lower than at baseline (both P < 0.001). Flows did not differ between right and left kidneys. Perfusion of either kidney did not change significantly in early diastole (P > 0.05), whereas it decreased significantly in mid-diastole (P < 0.001), rising dramatically in late diastole (P < 0.001) and with an additional slight increase in systole (P = 0.054). This study provides important insights into abdominal flows during intra-aortic pump counterpulsation. Furthermore, it supports the need to rethink the balloon design to avoid visceral ischaemia during circulatory assistance.

Detection of patients at high risk for nonocclusive mesenteric ischemia after cardiovascular surgery

Objectives

Nonocclusive mesenteric ischemia (NOMI) is a rare but life-threatening complication after cardiovascular surgery. Early diagnosis and treatment is essential for a chance to cure. The aim of this study is to identify the independent risk factors for NOMI based on the evaluation of 12 cases of NOMI after cardiovascular surgery.

Methods

We retrospectively analyzed 12 patients with NOMI and 674 other patients without NOMI who underwent cardiovascular surgery in our hospital. We reviewed the clinical data on NOMI patients, including their characteristics and the clinical course. In addition, we performed a statistical comparison of each factor from both NOMI and non-NOMI groups to identify the independent risk factors for NOMI.

Results

The median duration between the cardiac surgery and the diagnosis of NOMI was 14.0 (10.3–20.3) days. The in-hospital mortality of NOMI patients was 75.0%. Age (p < 0.05), peripheral arterial disease (p < 0.001), postoperative hemodialysis (p < 0.001), intraaortic balloon pump (p < 0.05), norepinephrine (NOE) > 0.10γ (p < 0.0001), percutaneous cardiopulmonary support (p < 0.001), sepsis (p < 0.05), loss of sinus rhythm (p < 0.05), prolonged ventilation (p < 0.0001), and resternotomy for bleeding (p < 0.05) showed significant differences between NOMI and non-NOMI groups. In the multivariate logistic regression model, prolonged ventilation [odds ratio (OR) = 18.1, p < 0.001] and NOE > 0.10 μg/kg/min (OR = 130.0, p < 0.0001) were detected as independent risk factors for NOMI.

Conclusions

We have identified the risk factors for NOMI based on the evaluation of the 12 cases of NOMI after cardiovascular surgery. This result may be useful in predicting NOMI, which is considered difficult in clinical practice. For the patient with suspected of NOMI who has these risk factors, early CT scan and surgical exploration should be performed without delay.

Evaluation of risk factors for a fulminant Clostridium difficile infection after cardiac surgery: a single-center, retrospective cohort study

Background

Clostridium difficile (CD) is the most common pathogen causing nosocomial diarrhea. The clinical presentation ranges from mild diarrhea to severe complications, including pseudomembranous colitis, toxic megacolon, sepsis, and multi-organ failure. When the disease takes a fulminant course, death ensues rapidly in severe and complex cases. Preventive screening or current prophylactic therapies are not useful. Therefore, this study was conducted to detect risk factors for a fulminant CD infection (CDI) in patients undergoing cardiac surgery.

Methods

Between April 1999 and April 2011, a total of 41,466 patients underwent cardiac surgery at our institution. A review of our hospital database revealed 1256 patients (3.0%) with post-operative diarrheal disease who tested positive for CD; these patients comprised the cohort of this observational study. A fulminant CDI occurred in 153 of these patients (12.2%), which was diagnosed on the basis of gastrointestinal complications, e.g. pseudomembranous colitis, and/or the need for post-cardiac surgery laparotomy. Demographic, peri-operative, and survival data were analyzed, and predictors of a fulminant CDI were assessed by binary logistic regression analysis.

Results

The 30-day mortality was 6.1% (n = 77) for the entire cohort, with significantly higher mortality among patients with a fulminant CDI (21.6% vs. 4.0%, p <  0.001). Overall mortality (27.7%, n = 348) was also higher for patients with a fulminant course of the disease (63.4% vs. 22.8%, p <  0.001), and a laparotomy was required in 36.6% (n = 56) of the fulminant cases. Independent predictors of a fulminant CDI were: diabetes mellitus type 2 (OR 1.74, CI 1.15–2.63, p = 0.008), pre-operative ventilation (OR 3.52, CI 1.32–9.35, p = 0.012), utilization of more than 8 units of red blood cell concentrates (OR 1.95, CI 1.01–3.76, p = 0.046) or of more than 5 fresh-frozen plasma units (OR 3.38, CI 2.06–5.54, p <  0.001), and a cross-clamp time > 130 min (OR 1.93, CI 1.12–3.33, p = 0.017).

Conclusions

We identified several independent risk factors for the development of a fulminant CDI after cardiac surgery. Close monitoring of high-risk patients is important in order to establish an early onset of therapy and thus to prevent a CDI from developing a fulminant course after cardiac surgery.

Intra-aortic balloon pump experience: a single center study comparing with and without sheath insertion

Introduction: The mechanical circulation support used in treatment of low cardiac output at most is the intra-aortic balloon pump (IABP). Its usage fields are the complications occurring due to ischemic heart disease, disrupted left ventricle function, and the low cardiac output syndrome occurring during coronary artery by-pass surgery.

Methods: During 28 years from 1985 to 2013, IABP support has been implemented to 3135 patients in our cardiac surgery operating theater and intensive care unit. The mean age of the patients was 61.4 ± 13.2 years (16-82). 2506 patients (80%) were the ones whom the cardiac surgery has been implemented. IABP support has been provided for 629 (20%) patients for medical treatment. We utilized IABP most frequently in coronary artery patients (70%). The first choice for placing the balloon catheter is the femoral artery in 3093 cases (98.7%).

Results: The most frequently observed balloon complication was the lower extremity ischemia in 383 cases (12.2%).The leg ischemia was statistically significantly more frequent in patients with sheath (P=0.004). The extremity ischemia has developed in 4 of 12 patients with balloon placed from upper extremity. The local bleeding and balloon rupture were more frequent in patients whom the balloon has been placed without sheath. The mortality due to IABP has occurred in only 5 patients.

Conclusion: Despite increase in IABP usage frequency rapidly, the complications due to catheter are still seen. We believe that the leg ischemia that is the most frequently seen complication can be prevented via IABP use without sheath.

Ambulatory Intra Aortic Balloon Pump in Advanced Heart Failure

Cardiac transplantation is the gold standard treatment for patients with advanced congestive heart failure that is refractory to maximal medical therapy. However, donor heart availability remains the major limiting factor, resulting in a large number of patients waiting long periods of time before transplantation. As a result, mechanical circulatory support devices have been increasingly used as a 'bridge' in order to sustain organ function and stabilise haemodynamics while patients remain on the transplant waiting list or undergo left ventricular assist device surgery. Intra aortic balloon pumps (IABP) are commonly used for temporary circulatory support in patients with advanced heart failure. IABP is traditionally placed percutaneously through the transfemoral artery approach. The major limitation with this approach is ambulatory restriction that can promote deconditioning, particularly in situations of prolonged circulatory support. A subclavian/axillary artery approach IABP insertion allows patients to be ambulatory during the pre-transplant period. In this review, we aim to summarise the physiology of IABP, the evidence for its use in advanced CHF and the efficacy and safety of subclavian artery IABP insertion.

Vascular complications following intra-aortic balloon pump implantation: an updated review

Background:

The use of the intra-aortic balloon pump (IABP) as a support device remains controversial due to the fact that a number of studies have shown no benefit in end mortality whilst using this device. One of the reasons for this could be the increase in vascular complications when using the pump. Therefore, the aim of the present review was to assess the current literature available with regards to IABP vascular complications during the clinical situation.

Methods:

A literature search was performed, searching for IABP complications in adult human studies between 1990 and 2016.

Results:

A total of 20 reports were identified as fitting the criteria of this study. The majority of vascular complications were limb ischemia, bleeding or mesenteric ischemia. The overall incidence of vascular complications ranged from 0.94% to 31.1%. Diabetes, peripheral vascular disease and hypertension, as well as smoking were all identified as risk factors for complications following IABP. Furthermore, studies supported the use of sheathless balloon insertion to reduce the risk of complications.

Conclusion:

Major vascular complications, including limb and mesenteric ischemia as well as bleeding and hemorrhage, have been associated with IABP. However, the incidence of these complications was generally low. Further studies are still required to truly understand the risk/benefit associated with the use of IABP.

A New 35-mm Short Intra-aortic Balloon Catheter: A Suitable Option Also for Non-Small-Sized Patients?

OBJECTIVE

Visceral ischemia can be a potentially life-threatening complication of intra-aortic balloon pump (IABP) support. A shorter IABP catheter might lead to a reduction of visceral complications. In this animal study, we evaluate the effects of a 35-mL short catheter in comparison with a 40-mL standard-sized catheter.

METHODS

Eighteen healthy swine underwent 120-minute ligation of the left anterior descending coronary artery followed by 6 hours of reperfusion being supported by either a short IABP catheter (short group) (n = 6) or a long IABP catheter (long group) (n = 6) or with no assistance (controls) (n = 6). Hemodynamics, visceral and coronary flows, as well as biochemical markers were evaluated throughout the different phases of the protocol.

RESULTS

Mesenteric flows increased significantly at reperfusion (P < 0.001 both) remaining constant afterward (all, P > 0.05) in the short group, while remaining significantly lower in the long group at the start of reperfusion, remaining constantly lower than the short group and controls (P < 0.001 vs short, P < 0.003 vs controls). In both long and short groups, catheters improved renal flows at reperfusion (P < 0.001 both) without any further variation (P > 0.05). In the short group, the flows were higher during the whole of reperfusion (all, P < 0.05). Intra-aortic balloon pump support improved hemodynamic indices and coronary blood flows during reperfusion to a similar extent in both the small and the long group (P > 0.05).

CONCLUSIONS

The short IABP catheter proved to be as effective as the standard-sized catheter in supporting hemodynamics and coronary circulation. Furthermore, it even improves visceral flows in comparison with conventional IABP catheters.

Influence of IABP-Induced Abdominal Occlusions on Aortic Hemodynamics: A Patient-Specific Computational Evaluation

Intraaortic balloon pump (IABP) is used as temporary mechanical assistance in case of cardiovascular diseases, even if different hemodynamic problems and, thus, clinical complications may happen, such as the decrease of visceral perfusion. A computational fluid dynamic (CFD) study was carried out to investigate the effects of different IABP-induced abdominal occlusions on patient-specific aortic flow. Two possible sizes (25 and 34 cm) and two locations (2 and 3 cm) of the balloon were compared, modeling four abdominal occlusions and numerically reproducing IAB inflation/deflation behavior. The results highlighted that the perfusion in renal, mesenteric, and iliac arteries decreases when the abdominal occlusion increases with balloon inflation. The study illustrates also how the balloon size affects the flow in aorta vessels in both locations, and that the positioning is of little relevance for the 34 cm balloon, whereas it influences the aortic flow very much in case of 25 cm IAB. This analysis demonstrates how the IAB-induced occlusion may vary the abdominal circulation; therefore, the correct size and positioning are emphasized for patient's outcome.

Is visceral flow during intra-aortic balloon pumping size or volume dependent?

AIM

We evaluated the influence of intra-aortic balloon size and volume on mesenteric and renal flows.

METHODS

Thirty healthy swine underwent 120-minute ligation of the left anterior descending coronary artery followed by 6 hours of reperfusion. Then, they were randomly assigned to the following five groups of animals, with six animals in each group: no intra-aortic balloon pump (IABP), a short 35-mL IABP, a short 40-mL IABP, a long 35-mL IABP and a long 40-mL IABP. Superior mesenteric artery (SMA) and renal flows were measured at baseline (t₀), at 2-hour ischemia (t₁) and every hour thereafter until 6 hours of reperfusion (from t_R1 to t_R6).

RESULTS

SMA flows increased significantly at t_R1 only in the two short IABP groups (p<0.001) and balloon volume did not appear to affect flows which, at any experimental time-point, were comparable using 35 mL or 40 mL balloons (p>0.05). Renal flows appeared to be influenced by balloon length, but not by volume. Indeed, flows in the renal arteries rose during IABP treatment; the increase was significantly higher in the short balloon groups and throughout the whole reperfusion (all, p<0.001).

CONCLUSIONS

Changes in visceral perfusion during IABP assistance were significantly related to balloon length, but not to its volume. This could be relevant for the evolution of balloon engineering design in order to reduce the incidence of mesenteric ischemia following IABP. Further research is necessary to confirm these findings.

IABP: history-evolution-pathophysiology-indications: what we need to know

Treatment with the intraaortic balloon pump (IABP) is the most common form of mechanical support for the failing heart. Augmentation of diastolic pressure during balloon inflation contributes to the coronary circulation and the presystolic deflation of the balloon reduces the resistance to systolic output. Consequently, the myocardial work is reduced. The overall effect of the IABP therapy is an increase in the myocardial oxygen supply/demand ratio and thus in endocardial viability.

This is an overall synopsis of what we need to know regarding IABP. Furthermore, this review article attempts to systematically delineate the pathophysiology linked with the hemodynamic consequences of IABP therapy. The authors also look at the future of the use of the balloon pump and conclude that the positive multi-systemic hemodynamic regulation during IABP treatment should further justify its use.

2015 SCAI/ACC/HFSA/STS Clinical Expert Consensus Statement on the Use of Percutaneous Mechanical Circulatory Support Devices in Cardiovascular Care (Endorsed by the American Heart Association, the Cardiological Society of India, and Sociedad Latino Americana de Cardiologia Intervencion; Affirmation of Value by the Canadian Association of Interventional Cardiology-Association Canadienne de Cardiologie d'intervention)

Although historically the intra-aortic balloon pump has been the only mechanical circulatory support device available to clinicians, a number of new devices have become commercially available and have entered clinical practice. These include axial flow pumps, such as Impella(®); left atrial to femoral artery bypass pumps, specifically the TandemHeart; and new devices for institution of extracorporeal membrane oxygenation. These devices differ significantly in their hemodynamic effects, insertion, monitoring, and clinical applicability. This document reviews the physiologic impact on the circulation of these devices and their use in specific clinical situations. These situations include patients undergoing high-risk percutaneous coronary intervention, those presenting with cardiogenic shock, and acute decompensated heart failure. Specialized uses for right-sided support and in pediatric populations are discussed and the clinical utility of mechanical circulatory support devices is reviewed, as are the American College of Cardiology/American Heart Association clinical practice guidelines.

Comparing short versus standard-length balloon for intra-aortic counterpulsation: results from a porcine model of myocardial ischaemia-reperfusion

OBJECTIVES

We compare a short and a standard-size balloon with same filling volumes to verify the differences in terms of visceral flow, coronary circulation and haemodynamic performance during aortic counterpulsation in an animal model of myocardial ischaemia-reperfusion injury.

METHODS

Eighteen healthy pigs underwent 120-min ligation of the left anterior descending coronary artery followed by 6 h of reperfusion, and they were randomly assigned to have intra-aortic balloon counterpulsation (IABP) with a 40-ml short-balloon (n = 6) or a 40-ml standard-length balloon (n = 6), or to undergo no IABP implantation (controls, n = 6). Haemodynamics and visceral and coronary flows were measured at baseline (t0), at 2 h of ischaemia (t1) and every hour thereafter until 6 h of reperfusion (from tR1 to tR6), respectively.

RESULTS

Mesenteric flows increased significantly at tR1 only in the short-balloon group (P < 0.001) and it was constantly higher than in the standard-balloon group regardless of mean arterial pressure, systemic vascular resistance and cardiac output (CO; all, P < 0.001). Renal blood flows were significantly increased during IABP treatment with values constantly and significantly higher in short balloons at any following experimental step (all, P < 0.05). IABP improved CO and coronary blood flow, and reduced afterload, myocardial resistances and myocardial oxygen consumption without differences between the short and the standard-length balloon (all, P > 0.05).

CONCLUSIONS

The short balloon prevents visceral ischaemia and, compared with the standard-size balloon, it does not lose IABP beneficial cardiac and coronary-related effects. Further studies are warranted to confirm our findings.

Ischemic Colitis Caused by Intra-Aortic Balloon Pump Counterpulsation

Intra-aortic balloon pump counterpulsation (IABP) has been shown to prolong life in critically ill cardiac patients. However, complications including distal emboli, balloon rupture, bleeding, limb loss, and bowel ischemia continue to be associated with them. We present a case of a 56-year-old male who suffered bowel ischemia as a result of a malpositioned IABP. While the benefit of such devices in critically ill patients is not disputed, patients as well as clinicians should be aware of the potential side effects and patients undergoing IABP placement should be monitored for complications.

Intra-Aortic Balloon Pump Malposition Reduces Visceral Artery Perfusion in an Acute Animal Model

Visceral artery perfusion can be potentially affected by intra-aortic balloon pump (IABP) catheters. We utilized an animal model to quantify the acute impact of a low balloon position on mesenteric artery perfusion. In six pigs (78 ± 7 kg), a 30-cc IABP was placed in the descending aorta in a transfemoral procedure. The celiac artery (CA) and the cranial mesenteric artery (CMA) were surgically dissected. Transit time blood flow was measured for (i) baseline, (ii) 1:1 augmentation with the balloon proximal to the visceral arteries, and (iii) 1:1 augmentation with the balloon covering the visceral arteries. Blood flow in the CMA and CA was reduced by 17 and 24%, respectively, when the balloon compromised visceral arteries compared with a position above the visceral arteries (flow in mL/min: CMA: (i) 1281 ± 512, (ii) 1389 ± 287, (iii) 1064 ± 276, P < 0.05 for 3 vs. 1 and 3 vs. 2; CA: (i) 885 ± 370, (ii) 819 ± 297, (iii) 673 ± 315; P < 0.05 for 3 vs. 1). The covering of visceral arteries by an IABP balloon causes a significant reduction of visceral artery perfusion; thus, the positioning of this device during implantation is critical for obtaining a satisfactory outcome.

Long-term prognosis and a prediction model for acute bowel ischaemia following cardiac surgery

OBJECTIVES

Bowel ischaemia following cardiac surgery is associated with a high postoperative mortality. No scoring system exists as yet to predict this complication following surgery. In addition, the long-term survival is not known. We sought to evaluate in-hospital outcomes and long-term outcomes in bowel ischaemia following cardiac surgery. We also sought to devise a simple risk prediction model for this catastrophic entity.

METHODS

This was a retrospective study of data entered prospectively into our cardiac surgical database between July 1999 and May 2014. We compared the short- and long-term outcomes of patients who developed bowel ischaemia following cardiac surgery with those who did not develop bowel ischaemia using propensity-matched analysis. We developed a prediction model for bowel ischaemia from logistic regression.

RESULTS

In total, 13 853 patients underwent cardiac surgery. Of these, 85 had confirmed bowel ischaemia following surgery. The in-hospital mortality rate for those with bowel ischaemia was 60%, while in those without bowel ischaemia, the mortality rate was 3% (P < 0.0001). In those bowel ischaemia patients who had a laparotomy for corrective surgery, the in-hospital mortality was significantly less compared with those who did not have a laparotomy (39.2 vs 91.2%, P < 0.0001). The long-term survival for bowel ischaemia at 2, 6 and 10 years was 35% (±5), 31% (±5) and 26% (+/6), respectively. Multivariable analysis revealed that advanced age at surgery, peripheral vascular disease, intra-aortic balloon pump usage, NYHA IV and postoperative atrial fibrillation were the significant (P < 0.005) determinants of developing postoperative bowel ischaemia. We developed a model to predict bowel ischaemia and validated it within our population (c-index = 0.781).

CONCLUSIONS

We have shown that whilst bowel ischaemia carries a higher short-term mortality, the long-term mortality is not significantly greater for those few who survive to discharge. We have developed a simple prediction model to identify those at high risk of developing bowel ischaemia following cardiac surgery in order to optimize perioperative strategies in future.

Intraaortic counterpulsation during cardiopulmonary bypass impairs distal organ perfusion

BACKGROUND

Recent studies have focused on the use of fixed-rate intraaortic balloon pumping (IABP) during cardiopulmonary bypass (CPB) to achieve pulsatile flow. Because application of an IABP catheter may represent a functional obstruction within the descending aorta, we explored the effect of IABP-pulsed CPB-perfusion with special attention to perfusion above and below the IABP balloon.

METHODS

Sixteen animals received an IABP catheter that remained turned off position (NP group, n = 8) or was switched to an automatic mode of 80 beats/min during CPB (PP group, n = 8). Flow-data and pressure-data were obtained above and below the IABP balloon. Tissue perfusion was evaluated by microspheres.

RESULTS

IABP-pulsed CPB-perfusion, as assessed at 30 minutes on CPB, increased proximal mean aortic pressure (p < 0.05) and carotid artery blood flow (p < 0.001), but decreased distal mean aortic pressure (p < 0.001). The decrease of distal mean aortic pressure in the PP group was associated with a 75 % decrease (p < 0.001) of renal tissue perfusion. During nonpulsed perfusion the respective variables remained essentially unchanged compared with pre-CPB levels.

CONCLUSIONS

Using IABP as a surrogate to achieve pulsatile perfusion during CPB contributes significantly to lowered aortic pressure in the distal portion of aorta and impaired tissue perfusion of the kidneys. The results are focusing on effects that may contribute to organ dysfunction and acute kidney injury. Consequently, assessment of perfusion pressure distal to the balloon should be addressed whenever IABP is used during CPB.

Acute bowel ischemia after heart operations

Acute bowel ischemia is a perioperative complication that is frequently unrecognized as a cause of death after cardiac surgical procedures, with an in-hospital mortality of 50% to 100%. In recent years, controversy regarding the most appropriate approach to resolve clinical or laboratory suspicion and the limited therapeutic options have led to very little improvement in patient prognosis. This article reviews the related literature examining the actual prevalence, pathophysiologic mechanisms, predisposing factors, diagnostic tests, and therapeutic approaches providing a glance at new promising tools in diagnostic workup.

PASSIVE COUNTERPULSATION: BIOMECHANICAL RATIONALE AND CLINICAL VALIDATION

Intra-aortic balloon counterpulsation (IABP) is the leading technique for cardiovascular support in most critical conditions. The beneficial effects of the procedure are widely known, but some drawbacks remain unsolved: high cost and controversial effect in presence of cardiac arrhythmia, both related to the control of intra-aortic balloon inflation and deflation. This paper describes the clinical validation of a completely passive solution (PIABP), which substitutes the time-controlled pumping system by a simple pressure-controlled reservoir. The test was performed on 10 patients, switching from IABP to PIABP and changing the reservoir pressure to obtain an optimal effect in terms of mean aortic pressure increase as an estimate of cardiac output. For each patient the reservoir pressure was increased in 10 mmHg steps and the aortic pressure was recorded together with electrocardiogram.

The PIABP showed a positive effect in all the patients, with a significant increase of the mean aortic pressure (+6.5%, p < 0.05) and of the mean pressure of the aortic pulse diastolic phase (+7%, p < 0.05). The change of heart rate between basal and optimal effect condition was not significant. Also an unexpected, significant increase of aortic maximal pressure (8%, p < 0.05) was found.

The proposed passive solution cannot be a substitute of the active one in all the situation, but may be useful in border line conditions, where the IABP is no more necessary but a ventricular support is still desirable.

Acute mesenteric ischemia after cardiac surgery: an analysis of 52 patients

OBJECTIVE

Acute mesenteric ischemia (AMI) is a rare but serious complication after cardiac surgery. The aim of this retrospective study was to evaluate the incidence, outcome, and perioperative risk factors of AMI in the patients undergoing elective cardiac surgery.

METHODS

From January 2005 to May 2013, all patients who underwent cardiac surgery were screened for participation, and patients with registered gastrointestinal complications were retrospectively reviewed. Univariate analyses were performed.

RESULTS

The study included 6013 patients, of which 52 (0.86%) patients suffered from AMI, 35 (67%) of whom died. The control group (150 patients) was randomly chosen from among cases undergoing cardiopulmonary bypass (CPB). Preoperative parameters including age (P = 0.03), renal insufficiency (P = 0.004), peripheral vascular disease (P = 0.04), preoperative inotropic support (P < 0.001), poor left ventricular ejection fraction (P = 0.002), cardiogenic shock (P = 0.003), and preoperative intra-aortic balloon pump (IABP) support (P = 0.05) revealed significantly higher levels in the AMI group. Among intra- and postoperative parameters, CPB time (P < 0.001), dialysis (P = 0.04), inotropic support (P = 0.007), prolonged ventilator time (P < 0.001), and IABP support (P = 0.007) appeared significantly higher in the AMI group than the control group.

CONCLUSIONS

Prompt diagnosis and early treatment should be initiated as early as possible in any patient suspected of AMI, leading to dramatic reduction in the mortality rate.

Nutrition intervention in the critically ill cardiothoracic patient

Despite acute myocardial infarction and cardiac surgery accounting for 2 of the most common reasons patients are admitted to the intensive care unit, little attention and investigation have been directed specifically for these patients. This patient population therefore deserves special attention as they are often malnourished but require emergent interventions, making nutrition intervention challenging. This article reviews current medical interventions implemented in critically ill cardiothoracic patients and discusses evidence-based nutrition therapy, including enteral and parenteral feeding, glycemic control, and antioxidant provision.

Intra aortic balloon pump: literature review of risk factors related to complications of the intraaortic balloon pump

The increasing use of the intra aortic balloon pump is attributed to the relatively easy percutaneous insertion and the low threshold of use over the past few years, especially in elderly patients with multi-vessel diseases and an affected ejection fraction.Unfortunately, the clinical assessment of the complications associated to the use of this supporting device, underestimates the frequency of such complications.This report has looked at the current literature and attempt to identify incremental risk factors related to the development of adverse effects during support with an intaaortic balloon pump.The paper concludes that in contrary to early reports, newer studies have shown that complications following intraaortic balloon pump treatment, is decreasing. Moreover the literature suggests that the thrombosis and infective complications are relevant to the duration of the pump treatment, while the ischemic problems of the limbs are mostly linked to the atherosclerotic status of the common femoral artery.