In this report, we describe an alternative approach for a case that was unsuitable for pacemaker implantation via the vena cava route.

A 64-year-old male patient who presented to the emergency room with complaints of pre-syncope and dizziness was diagnosed with atrial fibrillation and advanced atrioventricular block (Figure 1). Due to his hemodynamic instability, a temporary pacemaker was implanted via the right femoral vein. The patient suffered from chronic kidney failure and had been undergoing hemodialysis three times a week for a year. He had recently undergone a coronary angiogram, which showed insignificant circumflex stenosis. During intensive care follow-up, the patient was observed to be pacemaker-dependent, so a permanent pacemaker implantation was planned. His echocardiogram revealed depressed left ventricular systolic function with an ejection fraction of 35%. Physicians decided to implant a biventricular pacemaker due to a wide QRS complex on electrocardiogram and low EF. The patient had episodes of atrial fibrillation during intensive care follow-up, so to decrease the number of leads, we decided to implant only two leads (RV and LV).

The patient had a right subclavian hemodialysis catheter due to his chronic kidney disease, so left-sided venography was performed, revealing total obstruction of the left subclavian vein (Figure 2). Initially, we attempted to cross a wire and perform balloon dilatation to provide an open lumen for lead crossing. Unfortunately, this was not successful. With the absence of superior venous access to the heart, we considered other options. An iliac approach, although not previously described under these circumstances, is potentially a preferable alternative to thoracotomy for epicardial pacing.

Under deep sedation and in a supine position, an incision was made a few centimeters above the inguinal ligament. Dissection was performed, and the external iliac vein was identified by the cardiovascular surgeon (Figure 3). A temporary pacemaker lead, inserted via the right femoral vein, was used to locate the iliac vein. Next, the external iliac vein was punctured using a 16-gauge needle, and a wire was inserted. Over this wire, a peel-away delivery system (Selectra Extended Hook-55, Biotronik, Berlin, Germany) was introduced. The delivery system was advanced into the right ventricle over the guiding wire, and a long lead (CapsureFix Novus 5076-85 cm, Medtronic, Minneapolis, USA) was screwed into the apical position. Although previous case reports have described creating an alpha loop to manage apical position stability, the inadequate length of the lead in our case prevented us from creating a proper loop.¹ As a result, despite satisfactory measurements, the right ventricle lead remained tense. A second puncture was performed, and another delivery system was introduced into the coronary sinus. A long left ventricle lead (Attain Ability Plus 4296-88 cm, Medtronic, Minneapolis, USA) was then inserted into a stable and appropriate branch (Figure 4). After threshold testing (R wave sensing for RV lead: 12 mV and LV lead: 14 mV; threshold/impedence for RV lead: 0.7 mV/510 ohms and LV lead: 0.4 mV/470 ohms), the delivery systems were removed, and lead sleeves were anchored to the iliac area. A significant stenosis in the posterolateral branch of the coronary sinus prevented lead access over the wire, leaving no other option than to use anterior interventricular vein. Consequently, programming did not positively affect the QRS width. A subcutaneous pocket for the pulse generator (Enitra 8 HF-T, Biotronik, Berlin, Germany) was created in the medial area near the puncture site, just above the fascia of the oblique muscle wall in the lower right quadrant of the abdomen, due to the limited extracorporeal lead length (Figure 5)(Video 1). The wound was closed after irrigation with an antibiotic solution. The patient was immobilized for one day and discharged on the 7th day. At the 6-month follow-up, the patient was well, with good pacemaker performance as assessed by Holter monitoring and repeated pacemaker interrogation.

In the current literature, there are a limited number of case series reporting the use of the transiliac route. As far as we know, our case is the first reported biventricular pacemaker implantation via the iliac vein route.

The transiliac vein approach has been proposed as an alternative technique for pacemaker implantation when the pulse generator cannot be placed in the anterior chest wall due to factors such as thin subcutaneous tissue in the pectoral region, cosmetic reasons, superior vena cava obstruction, or previous epicardial lead failure.²³ Typically, epicardial electrodes are implanted through a subxiphoid approach for patients with superior vena cava obstruction. However, the subxiphoid approach can be challenging after cardiac reoperation due to adhesions.⁴ We did not have the opportunity to attempt subclavian/axillary venoplasty due to the absence of an experienced interventional radiologist. Epicardial lead implantation was not preferred due to hemodynamic instability and co-existing diseases that increased operative risks. In these situations, the transiliac vein approach is often easier to perform than epicardial lead implantation via thoracotomy. The major complication associated with the transiliac vein approach is lead dislodgment. Hess and colleagues⁵ reported a dislodgment rate of 0.8% using the subclavian vein approach, while Ellestad and Frenc⁶ reported a dislodgment rate of 7% for ventricular leads from the iliac vein. This issue should be considered when opting for the transiliac vein approach.

In this context, leadless pacing presents an innovative approach in cardiac electrophysiology by eliminating the need for traditional leads used in pacemaker systems. This method is particularly beneficial in scenarios where venous access is not feasible, such as in patients with complex vascular anatomy, venous obstructions, or those at high risk for lead-related complications. Leadless pacemakers are small, self-contained devices implanted directly into the heart muscle, usually in the right ventricle. Unlike traditional pacemakers that require leads to connect the device to the heart, leadless pacemakers are entirely self-contained. This technology offers several advantages, including avoidance of vascular complications, reduction in lead related complications, and being a minimally invasive procedure. However, there are some limitations to this technique, such as single-chamber limitation, extraction and replacement challenges, and cost considerations.

In our case, we aimed to perform a CRT (cardiac resynchronization therapy), which is not an option for leadless pacemakers. Current leadless pacemakers are primarily designed for single-chamber pacing. Additionally, cost considerations were also a decisive factor in our case due to the high cost of leadless pacemakers.

Other potential problems with the transiliac approach include lead fracture, thrombophlebitis, thromboembolism, and infection. While the transiliac approach for pacing is a viable alternative in specific cases, it carries associated risks, notably a higher incidence of deep vein thrombosis and the subsequent risk of pulmonary embolism. These complications arise due to the nature of the iliac vein’s location and its susceptibility to thrombosis. The mechanical presence of the pacing catheter can lead to endothelial injury, promoting thrombus formation. Once a thrombus forms in the iliac vein, it can dislodge and travel to the pulmonary arteries, causing a potentially life-threatening pulmonary embolism. This risk is compounded in patients with pre-existing conditions that predispose them to clot formation, such as our patient who had atrial fibrillation. To mitigate this risk, anticoagulation therapy is crucial for these patients. Administering anticoagulation therapy during and after the procedure can help reduce the risk of thrombus formation. However, this needs to be balanced against the risk of bleeding, especially in patients with contraindications for anticoagulation.

In our case, the patient was experiencing episodes of atrial fibrillation, so we used anticoagulation therapy with low molecular weight heparin (LMWH) due to its relatively short half-life. The last dose of LMWH was administered 12 hours before the procedure and continued afterward. Upon discharge, we started the patient on warfarin (Coumadin) to maintain anticoagulation, given that he was also a hemodialysis patient.

Although the transiliac approach could lead to thromboembolism, it is uncertain whether the complication rates are higher than those associated with the superior vena cava approach.

In conclusion, the transiliac implantation approach is a method to consider in cases where the regular superior vena cava approach is unsuitable or where there is a high risk for thoracotomy. We suggest that it is critical to use leads of appropriate length that suit the patient’s height and to utilize auxiliary catheters to maintain stable implantation. Selecting an advantageous region for the incision and creating the pocket are also important when connecting leads to the pulse generator, due to the limited extracorporeal lead length and the narrow space for manual work.

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