Outflow cannula position for left ventricular assist device: A propensity score-matched study.

OBJECTIVE: The clinical consequences of alternative outflow cannula positioning in patients undergoing left ventricular assist device implantation are unknown. We evaluated clinical outcomes in patients who underwent implantation with the outflow cannula implanted from the right side into the ascending aorta versus the left side of the pericardium. METHODS: Fifty consecutive patients with terminal left heart failure underwent implantation using the Medtronic Heartware Ventricular Assist Device at Toronto General Hospital. Patients were divided between left and right outflow cannula positioning during implantation where anastomosis occurred in the ascending aorta. Propensity score matching using exact matching on the following pre-specified covariates: Interagency Registry for Mechanically Assisted Circulatory Support score, previous cardiac surgery, and preoperative inotrope use. RESULTS: Fifty consecutive patients (25 left implantation and 25 right implantation) were included in the unmatched cohort and 45 patients (25 left implantation and 20 right implantation) were included in the matched cohort. No significant differences in baseline demographics. Pump thrombosis occurred in 10% (n = 2) receiving right-sided implantation and 8% (n = 2) with left implantation (p = 1.00). Postoperative stroke occurred in 10% (2/20) with right implantation and 16% (4/25) with left implantation (p = .88). No difference in 1-year mortality between right 20% (5/25) and left 25% (5/20) implantation (p = .97). CONCLUSION: No observed difference in mortality when adjusting for competing risk of heart transplantation. There was also no difference in stroke, pump thrombosis, driveline infection. Larger studies are required to confirm these findings. These preliminary data support the use of left-sided anastomoses to facilitate subsequent re-entry during heart transplantation.

Preprocedural ultrasound versus landmark techniques for spinal anesthesia performed by novice residents in elderly: a randomized controlled trial.

BACKGROUND: Spinal anesthesia using the midline approach might be technically difficult in geriatric population. We hypothesized that pre-procedural ultrasound (US)-guided paramedian technique and pre-procedural US-guided midline technique would result in a different spinal anesthesia success rate at first attempt when compared with the conventional landmark-guided midline technique in elderly patients. METHODS: In this prospective, randomized, controlled study, one hundred-eighty consenting patients scheduled for elective surgery were randomized into the conventional surface landmark-guided midline technique (group LM), the pre-procedural US-guided paramedian technique (group UP), or the pre-procedural US-guided midline technique (group UM) with 60 patients in each group. All spinal anesthesia were performed by a novice resident. RESULTS: The successful dural puncture rate on first attempt (primary outcome) was higher in groups LM and UM (77 and 73% respectively) than in group UP (42%; P < 0.001). The median number of attempts was lower in groups LM and UM (1 [1] and 1 [1-1.75] respectively) than in group UP (2 [1, 2]; P < 0.001). The median number of passes was lower in groups LM and UM (2 [0.25-3] and 2 [0-4]; respectively) than in group UP (4 [2-7.75]; P < 0.001). The time taken to perform the spinal anesthesia was not different between groups LM and UM (87.24 ± 79.51 s and 116.32 ± 98.12 s, respectively) but shorter than in group UP (154.58 ± 91.51 s; P < 0.001). CONCLUSIONS: A pre-procedural US scan did not improve the ease of midline and paramedian spinal anesthesia as compared to the conventional landmark midline technique when performed by junior residents in elderly population. TRIAL REGISTRATION: Retrospectively registered at Clinicaltrials.gov, registration number NCT02658058, date of registration: January 18, 2016.