Topical Vancomycin Effective in Reducing Surgical site Infecitons after Cranial Surgeries

A recent study conducted by researchers based in NIMHANS and AIIMS, and published in Neurology India suggests that topical vancomycin used in cranial neurosurgery procedures is quite effective in reducing post-op surgical site infections (SSIs) , including cases where implants like VP shunts have been placed.

World Health Organization (WHO) has recommended several steps to prevent surgical site infections (SSI) after cranial surgery, which include patient preparation before surgery, handwashing, and surgical site preparation. Despite these, the rate of SSI continues to be still high (1–9%) and it has become the most preventable healthcare-associated infection. A recent study involving 5,463 patients observed that the rate of SSI after common neurosurgical interventions was 1.94%, with the highest rate after vascular (3.4%) and CSF diversion procedures (3%).

A few studies have advised the application of systemic antibiotics for the prevention of SSI, especially in cases of shunts or drain, while other studies disagree stating it does not have an effect in reducing SSIs but also may be harmful as it enhances the possibility of growth of resistant microbes and clostridium difficile.

Topical vancomycin has emerged as an effective approach and several studies have shown that it has good efficacy in preventing SSI following spinal and orthopedic surgical procedures. This is due to its broad spectrum of action which covers almost all gram-positive cocci (Methicillin resistant staphylococcus aureus (MRSA), Methicillin sensitive staphylococcus aureus (MSSA), and Streptococci) which are the usual causes for cranial wound infection. Also, it has limited systemic absorption, thus, maintaining good local wound concentration without the risk of systemic toxicity.

S. aureus has been reported to be present in as many as 48.6% SSI, out of which 56% are resistant to beta-lactams. MRSA has been emerging as an increasingly common pathogen in postoperative infections, and thus, prompts the use of more selective antibiotics for prophylaxis such as vancomycin. In non-spinal neurosurgery, several risk factors have been identified as independently responsible for the increased risk of infections: male gender, age more than 60 years, smoking, lengthier preoperative hospital stay, surgery duration of more than 3 h, emergency surgery or re-exploration surgery, contaminated surgery, the use of implants, and CSF leakage Also, skin flora such as S. aureus, Cutibacterium acnes, and coagulase-negative staphylococcus further increase the applicability of vancomycin in-infection prevention bundles. 

The authors of this study evaluated the role of topical vancomycin in the form of an intrawound powder as a safe and effective modality based on available literature. Their analysisshowed  that only 1.6%  of the patients in the vancomycin group got SSIs as compared to 5.28% in the control group. Systemic vancomycin does not appear to be as beneficial; although studies are limited, available data suggest it to be no more beneficial compared to standard prophylaxis.This is in addition to its safety profile when administered locally as there have been low to non-existent levels of vancomycin detected in the serum. They found that topical vancomycin was useful in decreasing the risk of infections with a pooled risk ratio of 0.29. 

The applicability of topical vancomycin is especially enhanced due to its use in surgeries with deep brain stimulation as the implant infection mandates explanation of the implants. In DBS or IPG placement the pooled risk ratio was 0.24. This finding is understandable as intravenous levels of antibiotics given systematically have no bearing due to the avascular nature of the implants. Moreover, the use of topical vancomycin in pediatric cases is particularly beneficial as local administration reduces the systemic side effects. The pooled risk ratio of infection in the vancomycin group in pediatric patients was 0.09.

Topical vancomycin antibiotics prophylaxis is being currently utilized in various surgical specialties. It is warranted for operational sites where SSIs carry significant morbidity and mortality concerns. Data from neurosurgery has consistently demonstrated that antibiotic prophylaxis with vancomycin in cases where there is MRSA colonization in the anterior nares reduces the risk of SSIs. S. aureus is a skin commensal and colonizer of anterior nares in more than a third of the hospitalized patients and colonization before surgery is associated with an increased risk of postop S. aureus infections. As the most common organism causing SSIs are S. aureus, the efficacy of vancomycin found in our systematic review is understandable.

The authors agree that there are concerns regarding the breeding of antibiotic-resistant S. aureus with the widespread use of prophylactic topical vancomycin. However recent studies have shown that the application of topical vancomycin in spinal surgeries is not related to the growth of vancomycin-resistant bacteria. However, an increased incidence of infections caused by gram-negative bacteria was seen.  The retrieved studies reported no complications commonly associated with vancomycin, such as renal failure, skin rash, red man syndrome, anaphylaxis, seromas, or other local or systematic side effects. Even when the studies directly compared the adverse effects among two randomized groups, there were no differences in the cerebrospinal fluid (CSF) leakage, seroma formation, pseudo-meningocele, bone flap resorption, or seizures.

It can be concluded that the limited systemic absorption of vancomycin and broad-spectrum has led to its widespread applicability in the prevention of SSI in all types of cranial neurosurgery. Cases with implantable pulse generators, cranioplasty, and cerebrospinal fluid (CSF) diversion procedures have all demonstrated their unequivocal effectiveness.

Reference:

Deora H, Nagesh M, Garg K, Singh M, Chandra SP, Kale SS. Topical Vancomycin for Prevention of Surgical Site Infection in Cranial Surgeries: Results of an Updated Systematic Review, Meta-Analysis and Meta-Regression. Neurol India 2023;71:875-83

DOI: 10.4103/0028-3886.388107