Abdominal Emergency After Subcutaneous ICD Implantation.

We describe a previously unreported and potentially fatal complication of colonic perforation following the implantation of a subcutaneous implantable cardioverter-defibrillator in a young patient with nonischemic cardiomyopathy. We discuss the importance of technique and postprocedural evaluation for subdiaphragmatic complications. This description emphasizes presenting complaints, early recognition, and management strategies. (Level of Difficulty: Beginner.).

History of Presentation

A 47-year-old man presented for routine implantation of a subcutaneous implantable cardioverter-defibrillator (SICD) for primary prevention of sudden cardiac death in the setting of nonischemic cardiomyopathy with left ventricular ejection fraction of <35%. Given his relatively young age and lack of perceived cardiac pacing indication in the near future, a subcutaneous device was selected following shared decision-making discussions with the patient. After electrocardiographic screening for the device, the SICD implantation was performed under general anesthesia. The procedure was uneventful, and device evaluation including defibrillation threshold testing revealed no abnormalities. The initial postprocedural course was unremarkable, and the patient had no clinical complaints. The external appearance of the device and lead course were unremarkable. Routine follow-up radiographs were obtained the following morning, demonstrating normal device positioning with an ominous suggestion of free intraperitoneal air (Figure 1). Additional studies were undertaken for further assessment.

Figure 1

Postprocedural Chest X-Ray

The antero-posterior projection chest x-ray obtained the morning following device implantation demonstrating the presence of subdiaphragmatic air. The subcutaneous pacemaker is visualized on the left side.

Learning Objectives

To understand the causes, clinical presentation, differential diagnosis, and management of intra-abdominal complications following SICD implantation.

To be aware of the rare but serious complication of intraperitoneal introduction of the SICD lead if meticulous surgical technique is not adhered to.

To emphasize the timely recognition of subtle clinical signs of a potentially fatal complication of bowel perforation following SICD implant and consider routine postoperative radiographic imaging.

Past Medical History

The patient had a history of type 2 diabetes mellitus, mixed hyperlipidemia, and hypertension and was diagnosed with nonischemic cardiomyopathy with recent coronary angiogram revealing no obstructive coronary disease and left ventricular ejection fraction of 30%-35%. The patient’s family history was notable for one second-degree relative experiencing sudden death at a young age.

Differential Diagnosis

Diagnostic considerations included previously reported known complications such as pneumothorax or pneumomediastinum with subdiaphragmatic communication. Given the location of free air, bowel perforation was an important differential consideration.

Investigations

Repeat device interrogation revealed no abnormalities. Laboratory work results, including chemistry and complete blood count, were unremarkable, without interval development of leukocytosis or anemia. An upright abdominal x-ray was obtained and confirmed free intraperitoneal air inferior to the diaphragm (Figure 2). Serial clinical examination was performed, without interval development of abdominal pain or other symptoms. General surgery was consulted for evaluation and a computed tomography scan was ordered to assess the precise source of the free air and the course of the SICD lead. The computed tomography scan elucidated a moderate amount of pneumoperitoneum in the upper abdomen with associated fat stranding and a trace amount of fluid in the region of the distal transverse colon. The SICD lead was visualized entering the upper abdomen and transecting the distal transverse colon before re-entering the subcutaneous tissue of the inferior anterior thorax (Figure 3).

Figure 2

Postprocedural Upright Abdominal X-Ray

The upright abdominal x-ray obtained verifying the presence of subdiaphragmatic air. The subcutaneous implantable cardioverter-defibrillator lead can be observed traversing an area with colonic bowel gas patterns.

Figure 3

Postprocedural Abdomen Computed Tomography

Abdomen and pelvis computed tomography revealed the course of the subcutaneous implantable cardioverter-defibrillator transecting the left distal transverse colon before re-entering the inferior anterior thorax.

Management

The patient was subsequently taken for emergent exploratory laparotomy with complete device removal. The lead was found to be transecting across a segment of the distal transverse colon. Along with lead removal, bowel repair with omental patching was performed. He was managed perioperatively with antibiotics.

Discussion

Implantation of SICD devices has been recognized as a preferred management strategy in patient populations with challenging vascular access and decreased anticipated need for bradycardia or antitachycardia pacing. The SICD devices can eliminate the vascular complications associated with traditional transvenous ICDs and have fewer risks of infection. Also associated are lower rates of lead failure because of the lack of constant motion of the lead associated with a beating heart in traditional ICD systems. However, these devices are not free from their own unique risks, which include infection, inappropriate shocks, and system migration. In previously reported worldwide registry data and prospective clinical outcomes of SICD implantation, there have been several reported complications related to the implantation site, including pneumothorax, pleural effusion, hematoma, and even lead introduction in the intraperitoneal space.3, 4, 5 There have previously been reports of risk of bowel perforation with other peridiaphragmatic cardiac procedures, such as left ventricular assist device implantation, and transvenous ICD. However, this has not been described as a complication of SICD. To our knowledge, this is the first reported case of bowel perforation as a rare but potentially fatal complication of SICD implantation. The anatomic proximity of the intra-abdominal organs and the inferior chest wall subcutaneous space should be kept in mind while using the trocar to create a tunnel for the SICD lead. After introducing the trocar through the skin incision of the lateral chest wall in the subcutaneous space, the tip of the trocar needs to be directed outward against the skin while advancing it through toward the anterior chest wall incision. This is particularly important for patients with obesity for whom the abdominal contents may be protuberant and lie between the lateral and anterior chest wall incisions. Attention to proper technique ensures that the tunnel maintains its subcutaneous course without diving deeper into the chest wall or abdomen cavity, as happened in our case. The other notable finding of our case was the lack of significant clinical features associated with bowel perforation. The perforation was detected as an incidental finding of free air under the diaphragm in a routine postoperative chest x-ray done to assess the lead position. The lack of impressive clinical findings is likely attributable to the early detection of the complication, fasting state of the patient before the procedure, and sterile nature of the perforation. As in this case, the symptoms of bowel perforation in this setting may be clinically indistinguishable from expected postprocedural pain, and a high index of suspicion may be required to diagnose this complication if anticipated. Nonetheless, the development of acute abdominal findings and fatal sepsis are imminent after the perforation, and surgical intervention is indicated emergently, as was done in our case.

Follow-Up

The patient had an uncomplicated postoperative course and was discharged on postoperative day 3. He was evaluated at follow-up with no residual symptoms and plans for implantation of a single-chamber transvenous ICD. Repeat SICD implantation was considered; however, given postsurgical changes, fibrosis in subcutaneous tissues posing increased risk for infection, and patient preference, this option was not pursued.

Conclusions

We describe a rare and previously unreported complication of bowel perforation following SICD implantation. Operators should be aware of this potential complication and adhere to meticulous surgical technique to ensure the tunneling is restricted to the subcutaneous space. Furthermore, when evaluating patients postprocedurally, if the diagnosis of intra-abdominal perforation is anticipated, imaging should be undertaken immediately because early clinical signs may be subtle.

Funding Support and Author Disclosures

The authors have reported that they have no relationships relevant to the contents of this paper to disclose.