Sugammadex Reversal of a Large Subcutaneous Depot of Rocuronium in a Dialysis Patient: A Case Report.

Sugammadex is a modified gamma cyclodextrin that encapsulates rocuronium. We report the successful use of sugammadex in the management of an elderly man with end-stage renal failure who sustained an infiltration of subcutaneous rocuronium during rapid sequence induction of general anesthesia. Given the erratic absorption of subcutaneous rocuronium from the tissue, sugammadex was chosen to reverse the neuromuscular block at the end of the procedure. This report demonstrates the efficacy of sugammadex to reverse neuromuscular block in elderly patients with poor renal function. Moreover, the duration of action for sugammadex was sufficient to neutralize the ongoing absorption of subcutaneous rocuronium.

In vivo evaluation of a MR-guided 980nm laser interstitial thermal therapy system for ablations in porcine liver.

PURPOSE: To evaluate the use of a 980-nm diode laser for magnetic resonance-guided laser interstitial thermal therapy (MR-guided LITT) ablations in liver tissue in an in vivo porcine model. MATERIALS AND METHODS: MR-guided guided LITT was performed on nine juvenile pigs placed under general anesthesia. Target ablation sites were selected in the left and right lobes of the liver. Laser applicators were placed in the liver using intermittent MR guidance. Up to four separate ablations were performed in each animal using a 15 or 30 W laser generator using one or two applicators. During the ablations, continuous MR-based temperature mapping (MR-thermal mapping), using a proton resonance frequency technique, was performed to monitor the size of the ablation in real-time. Extent of thermal tissue damage was continuously estimated based on Arrhenius model. Two-minute ablations were performed at each site. MR-thermal mapping of ablations within the posteroinferior liver were accomplished with continuous breathing at low tidal volume. In the mid right lobe of the liver, due to motion artefacts, MR-thermometry was performed intermittently during breath hold periods. In the left lobe of the liver, ablations were performed with ventilation using positive end expiratory pressure (PEEP) of 10 cm of water. Upon completion, MR imaging with gadolinium contrast was performed to assess the extent of treatment. Thermal lesions were subsequently measured using both, MR-thermal dose and MR gadolinium images, for comparison. Following the animal euthanasia, the liver was harvested and subjected to formalin fixation and paraffin embedding for histological examination. RESULTS: Between one and four focal liver ablations (total 24 ablations) were successfully performed in nine animals with either a 15 or 30 W laser generator. For the 15-W laser generator, the average single applicator ablation size was (2.0 ± 0.5) × (2.6 ± 0.4) cm(2) , as measured by magnetic resonance (MR) thermometry, or (1.7 ± 0.4) × (2.2 ± 0.6) cm(2) , as measured with gadolinium contrast, with the difference being not statistically significant. For the 30-W laser generator, the average single applicator ablation size was (2.4 ± 0.3) × (3.3 ± 0.5) cm(2) by MR thermometry and (2.1 ± 0.4) × (2.9 ± 0.3) cm(2) by gadolinium enhancement, with no statistically significant difference. Simultaneously activating two applicators with the 15 W generator demonstrated ablation sizes of (3.7 ± 0.9) × (3.2 ± 0.1) cm(2) using MR thermometry and (2.3 ± 0.6) × (2.4 ± 0.3) cm(2) with gadolinium contrast, while using two applicators in the 30-W laser generator, yielded (4.5 ± 0.6) × (3.9 ± 0.2) cm(2) using MR thermometry and (4.4 ± 1.1) × (3.6 ± 0.5) cm(2) with gadolinium contrast enhancement. CONCLUSION: In our experience, we found that liver ablations performed with a MR-guided 980-nm diode LITT system through the saline cooled catheter applicator could be performed throughout the liver. Additionally, liver ablations were safe and produced a clinically applicable ablation zone. These results suggest the 980-nm diode laser MR-guided LITT system could be effective in treatments of hepatic tumors.

Feasibility of 3.0T magnetic resonance imaging-guided laser ablation of a cadaveric prostate.

OBJECTIVES: To demonstrate the feasibility of 3.0T magnetic resonance imaging (MRI)-guided laser ablation of the prostate. METHODS: MRI-guided laser ablations in the intact prostate gland were performed in 5 cadavers. The cadavers were brought into the MRI suite and placed in a supine headfirst position. A needle guide grid was placed against the perineum, and MRI was performed to co-localize the grid with the prostate imaging data set. Using the guidance grid and 14-gauge Abbocath catheters, the laser applicators were placed in the prostate with intermittent MRI guidance. After confirmation of the position of the laser applicators, 2-minute ablations were performed with continuous MRI temperature feedback. Using the relative change in temperature and the Arrhenius model of thermal tissue ablation, the ablation margins were calculated. RESULTS: Laser ablation was successfully performed in all 5 cadaveric prostates using 15- and 30-W laser generators. Thermal mapping in the axial, sagittal, and coronal planes was performed with calculated ablation margins projected back onto the magnitude MR images. Deviations of the needles from the template projections ranged from 1.0 to 4.1 mm (average 2.1) at insertion depths of 75.5-116.5 mm (average 98.2). In the 2 cadavers for which histologic correlation was available, the extent of the ablation zone corresponded to the temperature mapping findings and the ablation transition zones were identifiable on hematoxylin-eosin staining. CONCLUSIONS: Transperineal laser ablation of the prostate gland is possible using 3.0T MRI guidance and thermal mapping and offers the potential for precise image-guided focal targeting of prostate cancer.