gms | German Medical Science

Background: After disappointing results of the renal denervation therapy (SYMPLICITY HTN-3 trial), baroreflex activation therapy remains one of the promising therapeutical approaches for patients with drug- resistant malignant arterial hypertension. Since 2012, a minimally invasive system for barostimulation was introduced to the clinical practice. The aim of this study was to assess the influence of surgical and anesthetic technique on procedural course and to evaluate mid term results of barostimulation in hypertension management.

Materials and methods: Second- generation device (Barostim neo^TM) was implanted in 28 consecutive patients with refractory hypertension between Nov 2013 and Aug 2015 by the same surgeon at our institution. Stimulation lead was positioned unilaterally to one of the specified sites at carotid sinus and pulse generator was implanted ipsilateral in pectoral region. To prevent interference of psychical excitation and blood pressure regulation, general anesthesia is necessary for mapping of the carotid sinus. Anesthetic concept evolved during the study period: first 22 patients received general anesthesia, but due to experiences of pharmacological interference with electric sympathicolysis (mapping of the carotid sinus) last 8 patients received a combination of a very shallow general anesthesia and ultrasound-guided peripheral cervical plexus blockade (C3/C4). Barostim device was activated 4 weeks after procedure. Regular follow-up with 24-hours blood pressure measurements were scheduled at regular intervals. Procedural and follow-up data were retrospectively evaluated and statistically analyzed.

Results: Mean patient age was 60 ± 10 years with male gender in 64%. Drug- resistant hypertension was present in every patient in spite of 4 – 10 (median 6) antihypertonics. Typical risk profile included history of diabetes mellitus (44%), coronary arterial disease (40%), and mean BMI was 30 ± 2.

All leads and devices were implanted successfully. After excluding the effect of learning curve, major influence of anesthetic technique to the surgery course was shown. In patients with cervical plexus block, mapping of carotid sinus and search of optimal location for stimulation lead was easier, resulting in shorter surgery duration: mean of 88 minutes in solely general anesthesia compared with 55 minutes in anesthesia with cervical plexus blockade (p = 0.02). There were no major complications. The only procedural complication was one minor bleeding at the device pocket side, which was treated conservatively. Follow-up was completed in 22 patients (range 1-18 months, median 6 months) and showed clinically significant response to the therapy in 16 patients (73%). One patient suffered from discomfort at the stimulation site and wished deactivation of the device.

Conclusion: Implantation of second- generation baroreceptor stimulator is a safe and high effective therapeutical approach in patients with drug- resistant arterial hypertension. Special anesthetic techniques can facilitate implantation procedure.