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Surgical Aspects of the Possover LION Procedure
Table 1: IPG programs clinically observable findings; the minor seroma had disappeared
Program A Continuous stimulation using all four leads with the on day 14. The results from the CT scans are presented in Table 3.
lowest current intensity needed for subclinical skeletal Two patients did not show up for the CT scan on week 8 (marked as
muscle contraction. “missing”). No patients had seroma formation along the leads or IPG.
• Frequency: 5–10 Hz One patient had a visible displacement of two leads to
• Pulse width: 50–150 µs the femoral and sciatic nerves on day 10, requiring a surgical
• Current intensity: variable intervention with repositioning off the leads. A control CT 8 weeks
Programs Stimulation for 20–30 minutes during training sessions postoperatively showed that all leads were in place.
CT scans 8 weeks postoperatively revealed further
B and C every other day with current intensities needed for
minimal–maximal knee extension (B, femoral leads) displacement of the leads in three patients; clinically significant
and gluteal contractions (C, sciatic leads). displacement requiring surgery was found in one patient.
Replacement of the leads was not possible due to fibrosis in
• Frequency: 30–60 Hz the lumbosacral space, and the leads and IPG were removed.
• Pulse width: 50–150 µs Right SNEL in patient 13 migrated 1.5 cm up on control CT but
• Current intensity: variable was still in contact to the sciatic nerve. Left FNEL migrated 4 cm up,
Program D Stimulation on all four leads for training of stance and and right FNEL migrated slightly medially in patient 13 on control
gait. CT. Right FNEL migrated 5 cm up in patient 16 on control CT.
• Frequency: 30–60 Hz
• Pulse width: 50–150 µs
• Current intensity: variable dIscussIon
The Possover LION procedure is a promising new treatment for
paraplegic patients. It shares features with epidural spinal cord
and university degree in two patients. Nineteen patients had stimulation (SCS), which has recently been reported to induce the
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complete paraplegia ISCNSCI AIS A, while one patient was recovery of some motor function. It is a technically challenging
incomplete ISNCSCI AIS B. The spinal cord lesion was situated operation, but the presented series show that the procedure is
between Th3-Th6 in 10 patients and between Th7-Th12 in seven safe and with a similar or even more favorable risk of complications
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patients and between L1-4 in three patients. than SCS, which ranges from 8 to 75%. The Possover LION
procedure may be performed in a day-surgery setting, although
Bleeding we elected to admit patients until post-op day 1 in order to avoid
During operation, one patient had major bleeding of 900 mL, lead displacements.
which was stopped by locally applied hemostats. No transfusion The effect of both the Possover LION procedure and SCS on
was required. motion function in paraplegics is still controversial, and certainly
One patient presented with an intramuscular hematoma of more controlled studies are needed to determine the role of these
both pectineus muscles 8 weeks post-surgery, confirmed by CT scan. procedures. Our group will soon publish functional outcomes
This was caused by stretching of the muscles during physiotherapy from the randomized controlled study (substudy 2). A new
and ongoing stimulation and resolved without further problems. randomized controlled study is planned for year 2021, in which
we will investigate cardiovascular and musculoskeletal effects of
Infections the Possover LION procedure. Safety data from the present article
Pre- and postoperative blood samples (CRP) were obtained. will help to justify these new clinical studies.
One patient presented with infection in close vicinity to the A CT scan provides an accurate way of detecting lead
IPG 30 days post-surgery. Before this, the patient’s CRP values displacement. Twenty-five percent of the patients undergoing
were normalized on postoperative day 7. The discharge was sent CT scanning had a clinically significant lead dislocation,
for culture and sensitivity, uncovering a bacterial infection with although of the total patient group, only 10% had clinically
Staphylococcus aureus. The infection was managed with antibiotics significant lead dislocation. The scans were in concordance
(dicloxacillin) and negative pressure wound therapy; however, the with the clinical presentation, and patients similarly presented
infection did not resolve, and subsequently, the IPG and the two with a loss of muscle activation during stimulation from the
leads were surgically removed. dislocated leads, which indicated a need for re-operation. It
One patient suffered from a bladder infection that was treated was possible to access the lumbosacral space around post-op
with antibiotics. day 10, enabling safe repositioning of the displaced leads.
In our experience, surgery in the lumbosacral space past the
IPG-related Complications “surgical window” of approximately 12 days is not possible. This
Displacement of the IPG was observed in one patient. The IPG tilted emphasizes the importance of a routine CT scan 10 days post-op.
away from the fascia obstructing recharging the IPG. The patient Lead displacement was encountered during the first few days
was electively re-operated and had the IPG replaced. After this, no after surgery, but as shown in Table 2, the displacement may
further complications followed. One patient developed localized occur much later. Infection rates were acceptable, being around
necrosis of the skin covering the IPG site. The skin healed by locally 5% in this study, which is comparable to cardiac pacemaker
applied negative pressure wound therapy. implantations. 15,16 CRP-level measurements postoperatively
did not detect the one patient, who afterward developed an
Diagnostic Imaging infection. The CRP levels were normalized before the patient
In one patient, bedside ultrasonography showed a fluid collection reported discharge from the IPG site. The infection was
around the IPG on day 7. The patient had no other complaints nor localized and posed no threat to the patient. The removal of

78 World Journal of Laparoscopic Surgery, Volume 14 Issue 2 (May–August 2021)