High intensity focused ultrasound cyclocoagulation in dogs with primary glaucoma: a preliminary study

Treatment of canine and feline sarcoma using MR-guided focused ultrasound system

PURPOSE

In recent years, veterinary medicine has enhanced its applications beyond traditional approaches, progressively incorporating the Focused Ultrasound (FUS) technology. This study investigated the ability of FUS to precisely ablate naturally occurring canine and feline soft tissue sarcomas (STS).

METHODS

Six dogs and four cats with superficial tumours were enrolled in the study. The tumours were treated with a Magnetic Resonance guided FUS (MRgFUS) robotic system featuring a single element spherically focused transducer of 2.6 MHz. The tumours were then removed by surgery and sent for hematoxylin and eosin (H&E) staining.

RESULTS

The MRgFUS system was capable of inflicting well-defined overlapping lesions in the tumours. The anatomical sites of the treated tumours were the neck, leg, face, back and belly. Coagulative necrosis was evidenced by histopathology assessment in 80% of cases.

CONCLUSION

Therefore, this technology can be a therapeutic solution for veterinary cancer and a model for advancing the knowledge on human STS.

A High Intensity Focused Ultrasound System for Veterinary Oncology Applications

Background

Magnetic resonance-guided focused ultrasound surgery is an incisionless energy-based thermal method that is used for ablating tumors in the veterinary clinic.

Aims and Objectives

In this article we describe a prototype of a veterinary system compatible with magnetic resonance imaging intended for small-to-medium-sized companion animals that was developed and tested in vivo in adult rabbits.

Methods

Real-time monitoring of the ablation during the experiment was possible with MR thermometry. Experiments involved thermal monitoring of sonications applied in the thigh of the rabbits. A 38-mm diameter transducer operating at 2.6 MHz was used with a 60-mm-focal length. The robotic system employed 3 linear axes and one angular axis. For this study, only X and Y axis were enabled. Due to the target size limitations, motion in Z and Θ was not needed. The functionality of the positioning device was evaluated by means of MR thermometry, demonstrating sufficient heating and accurate motion in both axes of operation.

Results

The postmortem findings confirm the ability of the system to induce thermal ablations in vivo in the absence of adverse effects.

Conclusions

The device is a reliable and affordable solution for companion animal hospitals, offering and additional tool for the veterinary oncology society.

Efficacy and safety of high-dose ultrasound cyclo-plasty procedure in refractory glaucoma

AIM

To evaluate the efficacy and safety of high-dose ultrasound cyclo-plasty (UCP) for the treatment of refractory glaucoma in Chinese patients.

METHODS

In this 6-month retrospective study, 37 eyes of 37 patients suffering from severe glaucoma with uncontrolled intraocular pressure (IOP) of ≥21 mm Hg underwent 8-s ultrasonic cyclocoagulation with ten active piezoelectric elements. A complete ophthalmic examination was performed before and at 1d, 1, 3, 6mo after UCP. Therapeutic success was defined as IOP reduction from baseline ≥20% and IOP ≥5 mm Hg without adding new glaucoma medication compare to baseline at the 6-month follow-up visit. In addition to mean IOP at each follow-up visit, medications used and complications were also detected and compared to baseline.

RESULTS

After UCP procedure, the mean IOP was significantly reduced (P<0.01) from the preoperative 44.1±11.9 mm Hg to postoperative 26.7±11.8 mm Hg at 3mo, and 30.4±14.5 mm Hg at 6mo. The overall mean IOP reductions achieved at 3 and 6mo were 39% and 31% compared to baseline IOP. Sixty-one percent of patients responded well to UCP treatment with a mean IOP reduction of 48% at 3mo and 42% at 6mo. Ocular pain in most of patients were alleviated. No serious intraoperative or postoperative complications occurred.

CONCLUSION

High-dose UCP treatment is an effective and safe procedure to reduce IOP in Chinese patients with severe glaucoma.