Souheil F. Haddad, Patrick W. Hitchon, and John C. Godersky
✓ Pathological overgrowth of the epidural fat in the spine has been described and reported nearly exclusively in patients either with Cushing's syndrome or on chronic intake of glucocorticoids for a variety of clinical disorders. The authors report four patients with documented spinal lipomatosis (three pathologically and one radiologically). Only one of these patients received corticosteroids, and none had an underlying endocrinological abnormality. All four patients were adult males with a mean age at onset of symptoms of 43 years (range from 18 to 60 years). The symptoms ranged from simple neurogenic claudication and radicular pain to frank myelopathy. Myelography followed by computerized tomography were instrumental in the diagnosis of the first three patients; the fourth was diagnosed by magnetic resonance imaging. The thoracic spine was involved in two cases and the lumbosacral area in the other two. The different treatment modalities were tailored according to the symptomatology of the patients. These included weight reduction of an overweight patient with minimal neurological findings in one case and decompressive laminectomy and fat debulking to achieve adequate cord decompression in the remaining three cases. Two patients improved significantly, the condition of one stabilized, and the fourth required a second decompression at other spinal levels. The various modalities of treatment and their potential complications are discussed.
Hamdi G. Sukkarieh, Patrick W. Hitchon, Olatilewa Awe, and Jennifer Noeller
The authors sought to determine patient-related outcomes after minimally invasive surgical (MIS) lumbar intraspinal synovial cyst excision via a tubular working channel and a contralateral facet-sparing approach.
All the patients with a symptomatic lumbar intraspinal synovial cyst who underwent surgery at the University of Iowa Hospitals and Clinics with an MIS excision via a contralateral approach were treated between July 2010 and August 2014. There was a total of 13 cases. Each patient was evaluated with preoperative neurological examinations, lumbar spine radiography, MRI, and visual analog scale (VAS) scores. The patients were evaluated postoperatively with neurological examinations and VAS and Macnab scores. The primary outcomes were improvement in VAS and Macnab scores. Secondary outcomes were average blood loss, hospital stay duration, and operative times.
There were 5 males and 8 females. The mean age was 66 years, and the mean body mass index was 28.5 kg/m2. Sixty-nine percent (9 of 13) of the cysts were at L4–5. Most patients had low-back pain and radicular pain, and one-third of them had Grade 1 spondylolisthesis. The mean (± SD) follow-up duration was 20.8 ± 16.9 months. The mean Macnab score was 3.4 ± 1.0, and the VAS score decreased from 7.8 preoperatively to 2.9 postoperatively. The mean operative time was 123 ± 30 minutes, with a mean estimated blood loss of 44 ± 29 ml. Hospital stay averaged 1.5 ± 0.7 days. There were no complications noted in this series.
The MIS excision of lumbar intraspinal synovial cysts via a contralateral approach offers excellent exposure to the cyst and spares the facet joint at the involved level, thus minimizing risk of instability, blood loss, operative time, and hospital stay. Prospective randomized trials with longer follow-up times and larger cohorts are needed to conclusively determine the superiority of the contralateral MIS approach over others, including open or ipsilateral minimally invasive surgery.
Patrick W. Hitchon, Souheil Haddad, and Adel Afifi
Patrick W. Hitchon, Jeffrey M. Lobosky, Thoru Yamada, and James C. Torner
✓ Spinal cord blood flow (SCBF) in 10 sheep subjected to laminectomy at L6–7, T6–7, and C7–T1 was compared to that of 10 control sheep subjected to anesthesia alone. Blood flow was measured using the radioactive microsphere technique, with the PaCO2 maintained at 40 ± 2 mm Hg. Both laminectomy and control animals showed a decrease in SCBF at a rate of 7% to 16%/hr for the 3 hours following the first blood flow determination. When prelaminectomy and postlaminectomy SCBF values were compared to their counterparts in the control animals, there were no significant differences. Laminectomy does not appear to alter SCBF from control values. Spinal evoked potentials (SEP's) were elicited in the laminectomy group by direct cord stimulation at C-7 and L-7. No changes were noted in amplitude or latency of SEP's over time in either caudal or rostral conduction.
Ambur Reddy, Patrick W. Hitchon, Sami Al-Nafi, and Kent Choi
The authors report a case of entero-paraspinous fistula 2 years after T-12 corpectomy and instrumentation for spinal metastasis from renal cell carcinoma. The pathogenesis in the present case seems to have arisen from local recurrence of T-12 metastatic carcinoma in spite of radiation and corpectomy. As a result of previous nephrectomy and anterolateral dissection for the T-12 corpectomy, the jejunum adhered to the surgical site. Recurrent tumor at T-12 invaded the adherent small bowel loop, resulting in a fistulous communication between the small bowel lumen and the spinal wound. Loss of retroperitoneal fat, scarring, and adhesions from previous surgeries contributed to this complication by having the jejunum close to the T-12 corpectomy site, and eventually to its invasion by recurrent tumor. Avoidance of such a complication is difficult; however, total excision of the spinal malignancy, and when possible, creating a barrier cuff of fascia or fat around the spine to protect abdominal contents, are potential solutions.