Increasing role of cardiac surgeons in managing cardiac perforations during ever-expanding percutaneous interventions: a mini-review

Abstract

Iatrogenic cardiac injury is a catastrophic event and its management should be emergent. Cardiac surgeons need to be aware of basics related to the catheter-based intervention techniques and their outcomes. This mini-review discusses cardiac perforations and role of surgical team during catheter-based interventions.

Introduction

With the exponential improvement in the catheter-based techniques, utility for percutaneous interventions (PCI) is expanding rapidly. This mini-review discusses perforations during the interventions, and surgical management of these catastrophic complications.

Catheter-based ablation

Although, over the years, incidence of catastrophic complications is down-trending with the rise in number of cases in low- or medium-volume centres, there are regular reports of cardiac perforation requiring surgical involvement.

Atrial ablation

The most susceptible areas for traumatic perforation are the left atrial (LA) wall (appendage, mitral isthmus and posterior roof), right ventricle apex and distal coronary sinus [1]. The incidence of the cardiac perforation is low (0.52%); and in majority of the cases, aetiologies are mechanical trauma of thin walls of the LA myocardium (e.g. LA appendage, LA roof) and inadvertent pericardial entry during the transeptal puncture, and in “steam pops” during radiofrequency (RF) energy delivery [2]. The predictors of cardiac perforations are non-use of intracardiac echocardiogram (ICE), female sex, obesity and absence of previous cardiac surgery [2].

Bohnen et al. reported overall rate of cardiac perforation of 1.3% and it varies with the type of lesion set used, for example supraventricular tachycardia (SVT) lesion set had the lowest rate (1%), atrial fibrillation (AF) (1.8%) and ventricular tachycardia (VT) with structural heart disease (1.4%) [3]. Redo-ablation, linear LA ablation and use of RF power > 45 W are procedure-specific factors for causing tamponade.

Friedman et al. described results comparing AF ablation done in hospitals with or without cardiothoracic surgery (CTS) services on-site [4]. In the overall cohort, 30-day mortality was higher in patients ablated at a hospital without surgical backup (0.89% vs. 0.43%; P value 0.01), but all other outcomes were not significantly different. In propensity-matched analysis, there was no significant association between the presence or absence of on-site surgical unit and cardiac perforation, re-hospitalization or death. Diagnosis of the cardiac perforation typically occurred during the index hospitalization in 75.6% of the cases. Requirement of cardiac surgery and death after cardiac perforation were uncommon, with rates of 1.08% and 3.4%, respectively.

Cardoso et al. performed meta-analysis of pulmonary vein isolation (PVI) cases and they found that more cases developed tamponade and required surgical intervention after RF ablation compared to the cryo-ablation [5]. Reasons were point to point energy delivery, higher energy requirement and a longer procedure time with the former.

Ventricular ablation

Ventricular perforations need more surgical interventions and the reasons are higher systolic pressures and dissection of blood through the muscle fibres leading to multiple bleeding points. Predictors of higher complication rates are age > 70 years, female gender, obesity, serum creatinine > 1.5 mg/dl, previous coronary artery bypass grafting (CABG) surgery, congestive cardiac failure (CCF), poor left ventricular functions, longer procedure time, higher anticoagulation level and left-sided lesions [6].

Cardiac perforation and tamponade during VT ablation have been reported in around 1% patients and half of these cases need surgical repair [7]. Serious complications are higher in the structural heart disease cases compared to the idiopathic VT group (6–10% vs. 3% respectively) because of the longer procedure time and multiple ablations [8].

VT ablation requires higher energy and continuous catheter irrigation, which end up in excessive intra-myocardial heating and eventually causing steam pop. Steam pop leads to severe damage in the surrounding tissues and causes extensive tissue scars. Chances of steam pop increase significantly with larger impedance fall and higher requirement of energy doses.

Coronary artery injury

Iatrogenic coronary perforations (0.19–0.71%) and dissection (< 0.1%) are getting rare nowadays but once complication happens it needs urgent surgical attention, and even then 30-day mortality is very high (20.8%) [9]. Pre-operative cardiogenic shock and acute coronary occlusion during PCI were reported as high-risk variables for the outcome (hazard ratio 2.6, P – 0.002). Patient characteristics like female gender, old age, calcified coronary arteries, right coronary intervention, connective tissue disorders, aortic root calcification, chronic total occlusion (CTO) and anatomic variations are pronounced high-risk factors for the complication [10]. The commonest indications for emergent surgery were coronary artery dissection, followed by occlusion and perforation of the coronary artery.

Covered stents, coils, microspheres, proximal balloon inflation, thrombin injection, fat embolization, autologous blood clots and urgent cardiac surgery are different techniques described to tackle coronary perforations.

These cases are loaded with oral dual antiplatelet drugs and sometimes have intravenous infusion of antiplatelet agents. In these situations, off-pump coronary artery bypass grafting (OPCABG) can be an effective method to negate these factors [11].

Valvular interventions

Mitral valvuloplasty is reported with complications ranging between 1 and 10%, and 1% of the cases need urgent surgery [12]. Mechanism of the injury can be trans-septal perforation, left ventricular perforation with balloon dilatation, creation of large iatrogenic atrial septal defect (ASD) and small LA perforated during guidewire insertion. During these emergencies, most of the time, patients are not completely investigated and this further escalates the risk.

Aortic valve interventions and vascular access injuries

With the growing experience and referral of sicker cases for trans-catheter aortic valve implantation (TAVI), intervention lists are venturing through trans-apical, trans-ascending aorta approaches. In the PARTNER trial (Placement of Aortic Transcatheter Valves), 15.3% of patients had major and 11.9% had minor vascular complications within 30 days, including severe dissections (62.8%), perforations (31.3%) and large access-site haematoma (22.9%) [13]. Mechanism of the perforations could be acute aortic valve rupture with guidewire, left ventricular perforation, aortic root dissection, coronary ostia dissection and acute myocardial infarction.

Congenital interventions

Patent foramen of ovale (PFO) and atrial septal defect closure

Transcatheter PFO and ASD closure is a safe procedure; however, surgical intervention might be needed for the device thrombosis (0.6%), device embolization (0.07%), device fracture and serious bleeding from vascular complications (≤ 0.5%) [14]. Cardiac erosions (atrial roof or aorta) are the most feared and life-threatening complications of ASD closure using devices (0.3%).

Surgical interventions

Surgical teams are getting increasingly involved with interventional colleagues during these procedures, which include both planned assistance and emergency bailouts. Immediate sternotomy and surgical subxiphoid pericardial drainage are well-established surgical measures and left ventricular assist devices (LVAD) and veno-arterial extracorporeal membrane oxygenation (VA-ECMO) are new frontiers in this field [15].

VT ablation

Acute decompensation during VT ablation can be caused by VT storm, anaesthetic drugs and implantable cardioverter-defibrillator shocks. Institution of the ECMO during VT ablation provides extra time to ablate complete complex lesions by stabilizing haemodynamic condition and it also permits administration of antiarrhythmic medications with significant negative inotropic effects, without causing hypotension [16]. But use of mechanical circulatory support might increase complexity of the procedure and may be cumbersome to be performed without a hybrid theatre. Provaznik et al. have reported a retrospective series, where 44 cases were included and the most common chamber involved was the right ventricle, followed by the left ventricle (59% and 18% respectively) [17]. Surgical repair was required in 61.4% of the cases and overall mortality was 25% in a busy tertiary cardiac centre. On sub-group analysis, mortality was significantly higher in the left ventricular perforation patients compared to the right ventricular perforation cases (75% vs. 11.5% respectively). Mortality increased to 42% if cardiac tamponade remained persistent because of either delayed diagnosis or significant pericardial collection. Ventricular perforations require median sternotomy and then further assessment in most of the cases. They have advocated avoiding tamponade and maintaining good systemic perfusion as important factors to avoid poor outcomes.

AF ablation

Mostly, these tamponades are successfully managed with pericardiocentesis and surgical intervention is required in 16–50% of cases, depending on the type of electrophysiology (EP) procedure and patient characteristics [3, 4]. PVI has low complication rates and it is further reduced by use of the balloon catheters. In most of the cases, LA roof perforations were referred for surgical intervention, and the rest were managed with pericardiocentesis only.

Coronary perforation

Ellis classification is used by various authors in the past to describe coronary artery perforations and it describes perforations as types I (extraluminal crater), II (myocardial or pericardial blushing) and III (contrast streaming or cavity spilling) [17]. Ellis types 1 and 2 can be managed by interventional methods, such as over-stenting for localized coronary artery dissection, coronary artery balloon occlusion and pericardiocentesis. CABG is best recommended in type III Ellis perforation, although the use of covered stents represented an alternative and quicker treatment.

Lemmert et al. reported cardiac tamponade in 50.7% of cases following coronary perforation, 12.7% of cases needed urgent cardiac surgery to relieve the tamponade and 5.3% of patients required bailout coronary artery bypass surgery [10]. The left main and the left anterior descending (LAD) coronary arteries, being responsible for blood supply to the majority of the myocardial territory in most patients, were the most frequently injured vessels (47.7%) in their study.

Valvular intervention

Following balloon valvuloplasty, acute severe mitral regurgitation requiring mitral valve replacement was noticed in 1.79% patients in a recent report. On univariate analysis, female sex, age ≥ 40 years, eccentric valve calcification and Wilkin’s score ≥ 10 were more frequent in patients who developed acute mitral regurgitation (MR). Cardiac tamponade occurred in 1.23% of cases [12]. Mechanisms of the injury are non-use of echocardiography, during inter-atrial septal perforation, dilatation of the valve, device dislodgement and embolization.

The Mitraclip (Abbott Vascular, Menlo Park, CA), PASCAL (Edwards Lifesciences, Irvine, CA, USA), is the most often used device and various reports have documented rare complications ranging from tamponade, acute severe regurgitation, coronary compression and device dislodgement and requiring urgent surgery [18].

The Mayo Clinic reported vascular complications with balloon aortic valvuloplasty (BAV) in around 7.6% of patients, with 2% requiring urgent surgery, because of valvular complications. BAV is considered for the sicker cases and most often in bailout situations and that might be the reason for overall higher complications [19].

Miscellaneous cases

Other less invasive procedures like permanent pacemaker lead implantation, ECMO insertion, pericardiocentesis and transcutaneous pacing lead placement can also lead to cardiac chamber trauma and need surgical repair.

Role of hybrid theatres

Hybrid theatres (HTs) are still not available in every cardiac hospital because of financial or other logistical constraints. During the day, when cardiac theatres are busy, attending emergency in the catheter suite can be an issue and may lead to compromise in patient care. Having HT in the unit can avoid such delays and might reduce risk of haemodynamic instability during the waiting for the surgeons to arrive and shifting the patient to the operating room. The real issue is the full utility of HT, as reports suggest only 20% cases are done as “combined procedures” and the rest of the time HT is occupied by a single speciality. The total investment in building a HT is 120% times higher than regular operating theatre, and if utilization is not enough, then cost recovery may take years [20]. HT can be very well utilized for combined ablations, hybrid coronary artery revascularization, TAVI, congenital heart diseases and other miscellaneous interventions.

Conclusion

Complex interventions should not be undertaken by cardiologists unless they have a functioning heart team approach and the cardiac surgeon is included in the decision making. Team approach will not only reduce procedural risks but also avoid expensive interventions and drainage of the resources. Ideally, such interventions ought to be done in hybrid theatres. It is also important for surgeons to learn wire skills to better manage these life-threatening complications. Improvements in the risk assessment and mitigation of the complications during invasive procedures can be achieved by the team approach, consensual decision making and prompt action.

Funding

Author received no funding.

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The author declares that he has no conflict of interest.

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