Botulinum toxin in preparation of oral cavity for microsurgical reconstruction

The effect of botulinum neurotoxin A on soft-tissue complications in intraoral reconstructions

BACKGROUND

Intraoral reconstruction has become more common in recent years. Patients may suffer from complications because of hypersalivation. This issue can be overcome with an aid aimed at reducing saliva production. In this study, patients who underwent flap reconstruction were examined. The aim was to compare the complication rates between those who were administered with botulinum neurotoxin type A (BTXA) to the salivary glands before the reconstruction and those who were not.

METHODS

Patients who underwent flap reconstruction between January 2015 and January 2021 were included in the study. The patients were divided into 2 groups. BTXA was applied to the parotid and submandibular glands in the 1st group at least 8 days before the operation to reduce the salivary secretion. BTXA application was not applied to the patients in the 2nd group before the operation.

RESULTS

A total of 35 patients were included in the study. There were 19 patients in group 1 and 16 patients in group 2. The tumor type in both groups was squamous cell carcinoma. For patients in the 1st group, salivary secretion decreased in an average of 3.84 days. In the statistical analysis, no significant difference was found between the groups in terms of age, comorbidity, smoking-complication development, and comorbidity-complication development. When infection was excluded, there was a significant difference in the development of complications between the groups.

CONCLUSIONS

BTXA application before the operation is beneficial to minimize complications in patients who plan to undergo elective intraoral reconstruction.

Non-Surgical Strategies for Assisting Closure of Pharyngocutaneous Fistula after Total Laryngectomy: A Systematic Review of the Literature

Background: Pharyngocutaneous fistula (PCF) is a frequent complication after total laryngectomy, with an incidence of up to 65%. Many conservative or invasive approaches are available and the choice among them is usually made on a case-by-case basis. The aim of the present review is to critically summarize the available evidence of the effectiveness of the non-surgical management of PCF. Methods: A systematic review and a meta-analysis of the literature were conducted, according to the PRISMA guidelines. Studies investigating botulinum toxin therapy, scopolamine transdermal patch, hyperbaric oxygen therapy (HBOT), and negative pressure wound therapy (NPWT) were assessed. Complete fistula closure after the initiation of non-surgical treatment was the main outcome. Results: After the application of selection criteria, a total of seven articles and 27 patients were included in the present review. All the eligible studies were descriptive case series, while only one article used a standard group as a comparison. The mean age was 63.3 and 14 patients (51.9%) had previously received RT. The reported comorbidities were diabetes, ischemic heart disease, hypertension, dyslipidemia, COPD, and atrial fibrillation. With a mean healing time of 25.0 days, the overall success rate was 92.6%. Conclusions: Non-surgical treatment of PCF is only based on the experience of small series. Although success rates seem promising, the absence of properly designed comparative studies does not allow us, at present, to identify ideal candidates for these non-invasive management strategies for PCF.

Botulinum toxin A for oral cavity cancer patients: in microsurgical patients BTX injections in major salivary glands temporarily reduce salivary production and the risk of local complications related to saliva stagnation

In patients suffering from oral cavity cancer surgical treatment is complex because it is necessary to remove carcinoma and lymph node metastasis (through a radical unilateral or bilateral neck dissection) and to reconstruct the affected area by means of free flaps. The saliva stagnation in the post-operative period is a risk factor with regard to local complications. Minor complications related to saliva stagnation (such as tissue maceration and wound dehiscence) could become major complications compromising the surgery or the reconstructive outcome. In fact the formation of oro-cutaneous fistula may cause infection, failure of the free flap, or the patient’s death with carotid blow-out syndrome. Botulinum injections in the major salivary glands, four days before surgery, temporarily reduces salivation during the healing stage and thus could reduce the incidence of saliva-related complications. Forty three patients with oral cancer were treated with botulinum toxin A. The saliva quantitative measurement and the sialoscintigraphy were performed before and after infiltrations of botulinum toxin in the major salivary glands. In all cases there was a considerable, but temporary, reduction of salivary secretion. A lower rate of local complications was observed in the post-operative period. The salivary production returned to normal within two months, with minimal side effects and discomfort for the patients. The temporary inhibition of salivary secretion in the post-operative period could enable a reduction in saliva-related local complications, in the incidence of oro-cutaneous fistulas, and improve the outcome of the surgery as well as the quality of residual life in these patients.

GDNF overexpression fails to provoke muscle recovery from botulinum toxin poisoning: a preliminary study

Glial cell line-derived neurotrophic factor (GDNF) has potent axonal growth and survival effects on motoneurons. This study used transgenic Myo-GDNF mice to assess the effects of targeted GDNF overexpression on functional recovery after botulinum toxin type A (BTxA) chemodenervation. BTxA (0.1 U) was injected into the tibialis anterior (TA) muscle of wild-type CF1 and transgenic Myo-GDNF mice. On days 1, 7, 14, and 21 after injection, evoked muscle force production and muscle mass were measured (n = 6, for each group at each time point). Greater maximal tetanic force and calculated specific force were evoked in Myo-GDNF animals when compared with control CF1 animals at days 1, 7, and 21. However, the differences were not statistically significant. Similarly, modest reductions in muscle atrophy in the Myo-GDNF group at all time points were not statistically significant. Targeted overexpression of GDNF in the muscles of Myo-GDNF mice did not improve motor recovery in the first 21 days after BTxA chemodenervation.