# Preoperative Botulinum Toxin for Complex Diaphragmatic Paralysis: A Case Series

## TL;DR

This case series explores the use of preoperative botulinum toxin in complex diaphragmatic paralysis, showing safety and improved outcomes.

## Contribution

The novel application of preoperative botulinum toxin Type A in managing complex diaphragmatic paralysis is presented.

## Key findings

- Preoperative botulinum toxin Type A was safe with no postoperative complications or abdominal compartment syndrome.
- Patients showed significant improvement in respiratory function and quality of life six months postoperatively.
- Two patients remained asymptomatic with no recurrence at twelve months.

## Abstract

The management of giant diaphragmatic paralysis remains a significant surgical challenge, frequently associated with high rates of recurrence and the risk of developing abdominal compartment syndrome. While the use of Botulinum Toxin Type A (BTX- A) as an adjuvant therapy has been established in complex ventral hernia repair, its application in diaphragmatic paralysis is novel and sparsely documented. This study aims to present our institutional experience with BTX-A as a prehabilitation strategy in patients with complex diaphragmatic paralysis and to evaluate short- and long-term outcomes.

Three patients with complex diaphragmatic paralysis underwent preoperative administration as part of a prehabilitation protocol prior to surgical repair. Loss of domain (LD) was calculated using the Sabbagh formula. According to Sabbagh, LD is defined as the ratio of herniated volume to total peritoneal volume (LD = HV/TPV), with a loss >20% being considered significant. All patients received a standardized BTX-A administration protocol consisting of ultrasound-guided injection of 500 units of botulinum toxin type A, administered at six sites following the technique described by Smoot, with three injection points on each side targeting the internal oblique muscle 4 weeks before surgery.

Preoperative administration of Botulinum Toxin Type A (BTX-A) was safe in all three patients, with no postoperative complications or development of abdominal compartment syndrome, which was monitored through continuous intra-abdominal pressure measurements during the hospital stay (short-term outcomes). Six months postoperatively, all patients demonstrated significant improvement in respiratory function, assessed by standard pulmonary function tests, and reported improved quality of life, including relief from dyspnoea and enhanced daily functioning. At twelve months, two patients remained asymptomatic, with no clinical or radiological evidence of recurrence (long-term outcomes). Overall, preoperative BTX-A was associated with both short-term safety and sustained long-term functional benefits in this series.

Preoperative BTX-A appears to be safe and well-tolerated in complex diaphragmatic paralysis. The results suggest that BTX-A may reduce complications, improve functional outcomes, enhance respiratory function, and increase quality of life, with effects maintained for at least 1 year in most patients.