Complications of HIFU Ablation

Abstract

Any surgical procedure has potential complications. Abdominal and laparoscopic surgery may have heavy bleeding at operation, infection, poor wound healing, pelvic adhesion, ureter or bladder injury, bowel injury, and many others. HIFU ablation involves no wound, no bleeding, and is a type of noninvasive treatment. Complications are extremely low. However, organs and tissues close to the uterus include the bowel, bladder, nerves, and sacral bone, as well as the skin of the lower abdomen, may be within the acoustic pathway during the HIFU ablation procedure. Therefore, there is a potential for thermal injuries to these organs or tissues within the pathway, causing bowel perforation, bladder injury, nerve injury, bone damage, or skin burn. However, these are infrequent complications of HIFU treatment. As reported in the literature, skin burn incidence is about 0.2–0.5% [1], and the nerve injury, though reported in the early stage of HIFU ablation development, is now even much lower. Up to 99% of HIFU induced adverse events were mild and not requiring any special treatment [2]. From the literature, the severity of adverse effects was reported according to the SIR classification system for complications by outcome: (a) Class A: no therapy, no consequence; (b) Class B: nominal therapy, no consequence; (c) Class C: require therapy, minor hospitalization (<48 h); (d) Class D: required major therapy, unplanned increase in level of care, prolonged hospitalization (>48 h); (e) Class E: permanent adverse sequelae; (f) Class F: death. Class A and B were considered minor complications in this classification system; Class C, Class D, Class E, and Class F were considered major complications [3]. Although there were case reports of major adverse effects, including skin burn, bowel injury, acute renal failure, deep vein thrombosis, pubic symphysis injury, in the early literature. From a multicenter study with large data analysis, the complication rate during and after the HIFU ablation is mild in Class A and Class B. The complications were also much lower than laparoscopic surgery and conventional open surgery [4]. The major adverse events in Class C and D categories were only 0.38% [2].