Management of Intrathecal Pump Site Infection in a Patient with Metastatic Breast Cancer without the Removal of the System, a Case Report-Juniper Publishers
Juniper Publishers-Journal of Anesthesia
Abstract
Background: Intrathecal delivery of pain 
medication with an implantable infusion pump is being increasingly used 
for management of intractable pain in cancer patients. Infection of an 
intrathecal pump system is a rare but dangerous complication and usually
 leads to the removal of the whole system.
Case-Presentation: The author presents the 
case of a 69 year old woman who was diagnosed with metastatic breast 
cancer at presentation in 2009. She was treated systematically with 
chemotherapy and radiotherapy and underwent intrathecal pump 
implantation for targeted opioid delivery. Seven months after the 
implant, and a in a location of previous radiotherapy, she developed an 
infection at the site of the catheter insertion with exposure of the 
catheter itself. Clinically she presented with signs of local infection,
 high white blood cell count and back pain.She was treated with 
extensive surgical debridement of her back wound, removal the exposed 
intrathecal pump catheter and was started on intravenous ertapenem and 
later transitioned to levofloxacin and rifampicin for the duration of 3 
months.
Conclusion: The author reports a case of 
infection following implantation of intrathecal pump in a cancer patient
 can be treated with intravenous antibiotics without the removal of the 
intrathecal pump system.
Keywords: Methecillin sensitive staphylococcus aureus; Surgical site infection; Bacteroides stercoris, Peptostreptococcus prevotiiAbbreviations: CNS: Central Nervous System; MSSA: Methecillin Sensitive Staphylococcus Aureus; SSI: Surgical Site Infection
Introduction
Intrathecal pump system implies that the medication 
is administered directly into the central nervous system, which 
potentially reduces the side effects. Previous studies comparing the 
efficacy of intrathecal pump in association with medical management 
alone showed that at 4 weeks follow-up, 84.5% of patients in the 
intrathecal treatment group had clinical success vs. 70.8% in the 
conventional medical management group. The follow-up study revealed 
significant improvement in 6 months survival and also reductions in 
fatigue. [1,2]
There are numerous possible complications documented 
after implantation of intrathecal pumps including: post puncture 
headache, dislocation or leakage of the catheter, complication regarding
 medication inside the pump and infection of the system. The data on the
 incidence and management of infections of intrathecal delivery system 
in cancer patient population is rather sparse. In analogy with the 
protocols for the management of infections of cardiovascular devices, 
intrathecal pump system infections can be classified as: pocket site 
infections including soft tissue infection around the device and the 
segment of the leads (i.e., not the transvenous segment), deeper 
infections that are associated with hematogenous spread and spinal cord 
infections [3].
Other types of classification include: Primary site 
infection, in which the pump and its pocket is the site of infection, 
and secondary infection due to bacteremia from a different source.
Intrathecal pump system infection diagnosis is 
confirmed by identification or culture of microorganisms (mostly 
bacteria) on sample from a suspect surgical site or implant area. 
Clinical signs of soft tissue infection can include local tenderness, 
fever, erythema, wound exudate, wound dehiscence and or skin erosion at 
the site. A rare but potentially fatal complication of infection is the 
spread of infection to intrathecal space [4].
Case Description
This is a 69 year old female who had an intrathecal 
pain pump placed for treatment of intractable pain secondary to 
metastatic breast cancer to the spine, lungs and liver who subsequently 
underwent palliative chemotherapy and radiation therapy, including 
radiation to the lumbar spine several years prior to presentation. She 
presented to the hospital after two months of worsening lumbar area skin
 infection which was unsuccessfully treated with local debridement and 
was being followed by infectious disease and wound care. Due to 
worsening pain and need of a refill of the intrathecal pump, she 
presented to the pain clinic. At that time, the infection had worsened 
and a portion of the intrathecal catheter was exposed (Figure 1).
 She also had some serous fluid discharge from the lumbar wound. 
Clinical examination revealed she was oriented and alert and had no 
symptoms or signs of central nervous system (CNS) infection or systemic 
opioid toxicity.

Physical exam revealed the patient to be afebrile and
 a lumbar back wound with exposed intrathecal pump catheter and a large 
area of cellulitis surrounding it. There was clear involvement of the 
spinous processes and the catheter tubing itself. Her blood count was: 
Hct=35%, WBC=12.35, (polymorpho nuclear 90%, lymphocytes 7.1%), 
Platelets =300,000. Cultures from the site taken during debridement 
showed Bacteroides stercoris, Peptostreptococcus prevotii and 
methecillin sensitive Staphylococcus aureus (MSSA). Spine CT Scan showed
 mild edema within the bones particularly the L2 spinous process and 
soft tissue edema. No epidural collection or cauda equina compression 
was noted.
Plastic surgery, infectious disease and neurosurgery 
were consulted. After informed consent was obtained, she was taken to 
the operating room under general anesthesia for extensive wound 
debridement, however, upon attempted removal of the catheter, the 
catheter was severed and a portion it was left intrathecally. The pump 
itself did not appear to be involved and it was left in place. She was 
started on intravenous Ertapenem for 8 weeks and switched to 
Levofloxacin and Rifampicin. The wound was treated with wound vac and 
left open for secondary closure. She was discharged to a rehabilitation 
facility in stable condition while her intrathecal pump was infusing 
subcutaneously. Her pain was under control with the addition of minor 
oral opioids.
Discussion
Significant advances were made in the management of 
cancer- related pain with the release of the "pain ladder" by the WHO in
 1986, with an update in 1996 [5].
 Using this ladder, most cancer patients quickly advance to the use of 
strong opioid. As such, opioids continue to be the mainstay treatment 
for cancer pain. Unfortunately, when the WHO pain ladder is used, 
effective pain control is not achieved in approximately one third of 
patients. In addition, approximately 14% of patients do not achieve 
effective pain relief at any time [6,7]. For this reason, many pain practitioners have incorporated placing an intrathecal pump in the treatment of cancer pain.
Smith et al. [1]
 in 2001 conducted a randomized trial study comparing comprehensive 
medical management to medical management plus an intrathecal pump 
system. After that study in a subsequent paper with extended follow-up 
of the same patients was published in 2005 [1].
 These studies found that medical management plus an intrathecal pump 
system produced statistically significant reductions in reported pain 
scores and opioid related toxicities.
Intrathecal pumps are implanted to treat different 
types of pain in cancer patients. Since the intrathecal pump system 
releases prescribed amounts of pain medication directly to spine 
receptors, pain symptoms can be controlled using a smaller amount 
compared to the oral dose. Most people also experience fewer or more 
tolerable side effects, such as nausea and constipation, which can be 
devastating in cancer patients [8-10].
The major complications of the intrathecal drug 
delivery systems after pump malfunction and catheter issues are 
infection. The most common post-operative infection for these devices is
 a surgical site infection (SSI) [11].
 In the context of implantable devices, SSIs are defined as infections 
that occur within one year after implantation if the device is not 
manipulated and if the infection appears to be related to the operation.
 Even though intrathecal pump infection is not as common as other CNS 
infection due to prosthetic devices (like shunts), it remains among the 
most disabling and feared complications and is of particular concern 
because of the threat it poses to CNS infection. The range of infectious
 complications in previous reports with intrathecal drug delivery 
systems is from 2% to 8% [12].
Risk of surgical site infection in other clean 
surgical procedures like breast surgery is elevated in cancer patients 
(3-15%) compared to non-cancer patients (3%) [13]. Similarly, we expect a higher risk of infection following intrathecal drug delivery implantation in cancer patients.
General risk factors for SSIs that are pertinent to 
cancer patients include leucopenia associated with the cancer or cancer 
therapy, diabetes mellitus, debilitated status, poor nutritional status,
 smoking and possibly corticosteroid use [14-20].
 In addition, cancer patients frequently undergo treatment with 
chemotherapeutic agents and radiation, both of which can delay wound 
healing, increasing the risk of infection [16].
Infections of Intrathecal pump are dominated by 
bacteria of low virulence. The bacteria that are most frequently 
cultured in infections are the coagulate negative Staphylococci and 
Staphylococcus epidermidis (50-75% cases). Some of these bacteria have a
 unique property that appears to facilitate their colonization of 
tissue. The treatment of choice is usually considered to be removal of 
the entire infected pump system including the catheter and systemic 
antibiotics administration.
Conclusion
To our knowledge this was the first report of 
treatment of intrathecal drug delivery infection in a cancer patient 
without removal of an implanted intrathecal pump. We strongly believe 
that in cancer patients with low grade infection and mild clinical 
symptoms of infection, removal of intrathecal pump should not be 
considered as the first treatment option. We suggest initially starting 
conservative treatment including wound debridement and systemic 
antibiotics. If the treatment is started promptly, supported by our 
case, this may lead to avoidance of at least one surgical procedure and 
reduction of patient cost and risk.
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