Early Experiences with the SJ4 Connector System

The authors provide a brief case study describing their use of a new in-line connector, which reduces defibrillation connections from three to one as well as minimizes the number of set screws.

Background

   A 50-year-old male with a history of nonischemic cardiomyopathy (NICMP), asthma and longstanding hypertension with an ejection fraction (EF) of 20%, on optimal pharmacological therapy, was admitted electively for ICD implantation for primary prevention of sudden cardiac death. He was a tall, frail-looking gentleman, with a height of 72 inches and weight of 150 lbs.    When the patient arrived in the EP lab, it was apparent that his thin body habitus and lack of subcutaneous tissue would make device implantation technically challenging. Thinner patients run a higher risk of device erosion, especially in the bulky header area, from the loss of the subcutaneous fat layer. This layer acts as a cushion between the device and skin. Sub-pectoral implantation was an option in this patient, but his cachexia and loss of muscle mass magnified the risks of that approach, including damage to neurovascular bundles, loculated hematomas and chronic pain.    As previously discussed, the patient’s body habitus was a primary focus — our concerns centered on the bulkiness of a traditional ICD with its standard header. Therefore, we chose St. Jude Medical’s new SJ4 connector system, which would make for a less bulky header with its single lead connection, and would substantially reduce the volume occupied by the entire defibrillation system, thus permitting a traditional pre-pectoral approach.    The SJ4 connector system (St. Jude Medical, St. Paul, MN) features a single connection between the device and the defibrillation lead, and a single set screw (used to tighten and secure the lead to the device). Previous defibrillator lead designs required three separate connections and four set screws. The reduced number of lead connections lessens the bulk of the lead at the implant site, which helps reduce the risk of lead-to-can abrasions and subsequent skin erosion.

Case Presentation

   We were able to obtain dual axillary venous access following a venogram using the Seldinger technique. We chose to use a 7 French sheath to place the ventricular lead, a St. Jude Medical Durata^TM 7121 (one of the thinnest available defibrillation leads), to minimize the risk of back bleeding and air embolism. The leads were successfully placed in the right atrial appendage and right ventricular apex with excellent sensing and pacing parameters.    Other benefits discovered during the procedure were the speed and simplicity of a single connection and set screw of the SJ4 device. This contrasted sharply with the industry standard of three separate connections when using a dual coil ventricular lead with a minimum of four set screws. While uncommon, incorrect header connections have been made in the past, resulting in further unnecessary surgical procedures for the patient as well as wasted health care resources. Furthermore, the reduced bulk of the device header, as well as the use of a shorter Durata 7121 lead and less lead “wrap” reduced the potential for twiddler's syndrome.    The reduction in device pocket volume allowed us to place the device in the pre-pectoral plane and successfully close the subcutaneous tissues and skin in layers despite the patient’s habitus, resulting in a much better looking pocket, without the bulkiness we typically see in thin patients with implanted defibrillators.    At one-month follow-up, the patient presented without complaints related to his device. In addition, the surgical incision had healed nicely.

Conclusion

   By choosing the SJ4 system for this case, we were able to utilize a traditional pre-pectoral approach in this cachectic patient and thus avoid sub-pectoral implant and its attendant risks. A decrease in device pocket volume may improve patient comfort, be more cosmetically appealing, as well as reduce the potential for twiddler's syndrome.    Other groups of patients that might benefit from a smaller header include female patients concerned about the resultant cosmetics associated with ICD implants, the pediatric population, and other patients in whom pectoral “real estate” is limited.    The simplicity of the lead to connector placement with the in-line set screw as opposed to the presently available standard, with as many as 5 or 6 set screws in some devices, makes for easier and safer connection. In addition, since the Durata lead at 7 French is the smallest diameter high-voltage impedance lead available, this can prove important in patients with difficult access, and narrowed and tortuous vessels; it can also reduce the incidence of back bleeding and air embolism. The smaller-sized silicone back-filled lead may also prove easier to extract in the future, should the need arise. We feel the SJ4 in-line header makes lead connections fast, simple and accurate. Disclosures: Dr. Rhine has no conflicts of interest to report. Dr. Hart reports that he is a consultant with St. Jude Medical. Editor’s Note: This article underwent peer review by one or more members of EP Lab Digest’s editorial board.