Third Project in Lab: Salvage Procedures in Neuromodulation (pt. 1)

Meli N.
Apr 7, 2022
4 min read

In my April Signature posts, I will detail the third project that I worked on in the lab. To understand this study, you first must know a little more about the risks of neuromodulation.

From my previous descriptions of studies, you should have a general idea of what neuromodulation is. For example, spinal cord stimulation (SCS), is a type of neuromodulation. Other types of neuromodulation involve deep brain stimulation (DBS) and intrathecal (IT) pumps. SCS and IT pumps are effective ways to treat chronic pain while DBS is used to treat symptoms of Parkinson's disease.

DBS, SCS, and IT pumps are all treatment options that involve the implantation of a device, resulting in the chance of infection. Infection is one of the most serious complications of neuromodulation. Infection rates in SCS range from 0-10% of procedures, infection rates in DBS range from 1-9% of procedures, and infection rates in IT pumps range from 3-15% of procedures.

Although these treatment options yield high success rates in treatment, infection is a serious risk. Surgical site infection (SSI) can decrease the benefits of the procedure and increase patient morbidity. External factors such as diabetes, obesity, and tobacco use have been proven not to contribute to SSIs. A significant amount of SSIs result in complete device explantation: a waste of materials and waste of a procedure. Thus, new methods of treating and preventing SSIs are essential to be explored.

It would be ideal to avoid infection and prevent complications by improving surgical techniques and preventative measures. The US Centers for Disease Control has previously published guidelines for preventing SSIs. However, these are not applicable to every case and must be adjusted according to each specific patient case.

Preventative Measures in SCS

One study created and utilized an infection prevention bundle (IPB) that included pre-op questionnaire and counseling, pre-op checklist, body decolonization, pre-op weight-based antibiotics, strict draping and surgical techniques, post-op weight-based antibiotics, and post-op wound care education. This study found that post-IPB infections for SCS were 0% in both 90 day and 1 year surveillance periods, and therefore concluded that the use of the IPB was effective in decreasing SCS infection.
Studies have found that removing nonessential people in the operating room was related to a decrease in infection.
Prevention strategies for SCS infection have also been inferred from other surgical disciplines. For example, the use of a microbial envelope (commonly used to prevent cardiac device infection) has been explored in reducing SCS infection.
One study found that the use of strict asepsis, double layer hydrocolloid dressing during the trial, prophylactic antibiotics, operator experience, and patient education resulted in reduced SCS infection rates. However, other studies question antibiotic prophylaxis’ effectiveness.
Another study found that the use of sterile occlusive dressing has been related to lower infection rates.
It can be beneficial to utilize no-touch surgical techniques when handling equipment during device implantation

Preventative Measures in DBS

The previously mentioned study that utilized the IPB (pre-op questionnaire and counseling, pre-op checklist, body decolonization, pre-op weight-based antibiotics, strict draping and surgical techniques, post-op weight-based antibiotics, and post-op wound care education) also studied its effects on DBS infection rates.The study found that post-IPB infections for DBS were 0% in a 90 day surveillance period and 0.3% in a 1 year surveillance period, thus concluding that the use of IPB was effective in decreasing DBS infection rates in addition to SCS infection rates.
Another study found that the use of intraoperative vancomycin powder resulted in a DBS infection rate of 1.3%, which is also significantly smaller than the typical infection rate (1-9%).
Other infection prevention techniques for DBS involve patient understanding of risk factors and multi-staged surgical plans
It can be beneficial to utilize no-touch surgical techniques when handling equipment during device implantation

Preventative Measures in IT Pumps

The study that investigated the effectiveness of the IPB (pre-op questionnaire and counseling, pre-op checklist, body decolonization, pre-op weight-based antibiotics, strict draping and surgical techniques, post-op weight-based antibiotics, and post-op wound care education) in reducing infection in SCS and DBS also studied its effect on IT pump infection. The study found that the infection rate for IT pumps implanted with the IPB was 0.8% for a 90 day surveillance period and 1.6% for a 1 year surveillance period, reinforcing the claim that the IPB developed was successful in lowering infection rates for IT pumps (in addition to DBS and SCS).
Some modern pumps have retentive filters in an attempt to prevent infection, but these filters do not hold up against heavy loads of bacteria.
Another method to prevent infection involved reducing opportunities to introduce contaminants by refilling IT pumps as aseptically and infrequently as possible.
It can be beneficial to utilize no-touch surgical techniques when handling equipment during device implantation