Objective: Hypertension is the leading attributable cause of cardiovascular mortality worldwide. Patients with hypertension have multiple comorbidities including high rates of concomitant renal disease. Current pharmacological approaches are inadequate in the treatment of resistant hypertension. Renal sympathetic denervation (RDN) has been shown to effectively treat resistant hypertension. The traditional use of iodinated contrast in RDN is contraindicated in patients with significant renal insufficiency. In patients with renal impairment, carbon dioxide (CO2) can be used as an alternative contrast material for RDN. This article describes the technical aspects of RDN using CO2 angiography. Methods: Our centre is experienced in the innovative RDN procedure using CO2 angiography. We describe the protocol for CO2 angiography for RDN using a home-made CO2 delivery system and the Symplicity™ (Minneapolis MN 55432 USA) catheter (Medtronic) device. Results: CO2 angiography is an excellent alternative to iodinated contrast for RDN procedures. Conclusion: CO2 angiography for RDN is a safe and effective alternative to iodinated contrast. RDN using CO2 angiography is an easy and feasible procedure that can be used in patients with renal insufficiency or iodinated contrast allergies. Advances in knowledge: There is a paucity of descriptive reports for CO2 angiography for RDN and we provide details of the optimal protocol for the procedure. In particular, we describe the use of a Symplicity Spyral™ catheter (Medtronic), which has not been reported to date for use in this procedure.

Background:The "All-on-4" technique using 4 implants that has gained popularity in full arch edentulism cases in recent years was presented as a modern technique in implant-denture rehabilitation by Malo in Lisbon, Portugal, for the first time in 2003 and the all-on-four concept that began to be used in atrophic full arch mandibular and in the maxilla in 2005 has emerged.Aim: evaluation of dental implant stability in relation to All-on-4 concept.