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LVAD DRIVE LINE INFECTION
Authored By: Andrew Homb and Jerold Wallis, Assoc Prof of Radiology.
Patient: 21 year old female
History:

21 year-old woman with severe post-partum cardiomyopathy

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What device has been placed?

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Figure 1

Figure 2

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The�device was placed approximately 1 year and 9 months ago and there is now purulent discharge at the drive-line skin entrance site.� What study would you like to perform next?

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Figure 3

Figure 4

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Findings and their significance?

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Next�step in management?�

Image Size:[small][as-submitted]

Fig. 1
Chest Radiograph

Fig. 2
Abdomen Radiograph

Fig. 3
In-111 WBC planar imaging at 24 hours

Fig. 4
In-111 WBC planar imaging at 24 hours additional views
Image Size:[small][as-submitted]

Findings:

Limited Leukocyte Scintigraphy

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RADIOPHARMACEUTICAL: 0.46 mCi In-111 labeled autologous leukocytes i.v.

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Focus of increased tracer uptake in the superficial anterior right mid abdomen�

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Microbiology (drive Line)

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Rare gram positive cocci

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Follow Up

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The patient was subsequently treated with an LVAD drive line exit site revision

DDx:

Leukocyte scintigraphy evaluates the extent of drive-line and device involvement.

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Exit site only

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Exit site and drive-line

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Exit site, drive-line, and device

Diagnosis:

Left Ventricular Assist Device (LVAD) drive line infection, relatively superficial�in location�at the skin entrance site.

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General Discussion:

Full History:

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21 year-old woman with severe post-partum cardiomyopathy.��A left ventricular assist device�has been in�place for 1 year and 9 months. She now has purulent discharge at the drive line skin site and leukocyte scintigraphy is requested to evaluate for infection.�

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Discussion:

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LVAD drive-line exit site infection is an expected consequence and a significant limiting factor in long-term support.� It is believed that drive-line trauma is the most common initiator of drive-line exit site infections.� Trauma is usually in the form of shearing traction or torsion injury caused by common events such as dropping the controller and battery pack, hooking the drive-line on a passing object.� These stress then cause disruption of the adherent interfacce between the skin and the subcutaneous tissues and the velour covering of the drive-line.� The disruption then never heals due additional microtrauma leading to neo-epithelialization and tract formation that is ideal for development of superimposed infection.� If the body seals the exit site with proteinaceous matarial, the infection can then extend further along the drive line towards the pump pocket.

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Treatment immediately after trauma is immobilization of the drive-line to allow the�disruption to�heal.� If a tract is already formed, treament consists of antibiotics�and�aggressive surgical resection�of the tract back to the point�of adherence.� Antiobiotics alone has not proven effective.� If the tract is to close to the pump pocket,�local surgical excision�of the exit site and placement of a drain is performed.� If the pump pocket is involved, a drain is placed, the surgery is terminated, and further options are�assessed.�

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Role of Leukocyte scintigraphy:

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Leukocyte scintigraphy is perfomed during the course of antibiotic treatment and "has proven highly accurate in preoperative prediction of tract anatomy, and therfore in the extent of exit site excision that will be required."�

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"An isolated hot spot at the exit site alone suggest that a very limited exicision will suffice.� A hot spot at the exit site with a small trail of activity extending up the drive-line , unfortunately suggests that a more extensive exit site incision may be required to reach a circumferentially adherent area of the drive-line.� Worse yet, a trail of activity up to and involving the implanted device itself suggests that it may be too late�for surgical intervention."��

References: Pasque et al. "Surgical Management of Novacor Drive-Line Exit Site Infections" Ann Thorac Surg. 2002; 74:1267-1268.
Comments:
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Additional Details:

Case Number: 245518Owner(s): Andrew Homb and Jerold Wallis, Assoc Prof of RadiologyLast Updated: 02-07-2013
Anatomy: Cardiopulmonary   Pathology: Infection
Modality: Nuc Med, OtherAccess Level: Readable by all users, writable by NucMed Certifiers
Keywords: iwnm

Case has been viewed 39 times.
Certified by Jerold Wallis on 07-28-2010

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