Faculty Bibliography

OBJECTIVES/OBJECTIVE:To understand that young athletes have a higher incidence of pars interarticularis defects than the general population. This may be due to an immature spine put under higher stress loads at an early age. Traditionally, surgery was reserved for those who failed conservative therapy, and consisted of open exposure, bone grafting and placement of pedicle screws. This leads to a long recovery period and limited ability to return to competitive sport. METHODS:Four collegiate and professional level athletes, three high school athletes, and one member of the National Guard presented with back pain from spondylolysis without spondylolisthesis. All underwent minimally invasive surgery (MIS) to directly repair the pars defect, for a total of sixteen pars defects repaired in eight patients. Described is an application of a MIS pars repair technique that has not previously been reported, which recreates the normal anatomy rather fusing across a motion segment. RESULTS:Five patients were discharged the day following surgery and three were discharged on postoperative day 2. Six of the patients returned to their previous level of competitiveness. Two were unable to achieve the same level of play, both of whom failed to fuse the spondylolysis. Patients all initially reported clinical improvement postoperatively and there was overall mean improvement on patient reported outcome measures (SF36 physical and mental component scores, visual analog scale, and Oswestry disability index). CONCLUSION/CONCLUSIONS:MIS advantages include less muscle tissue disruption and restoration of the natural anatomy. This leads to a more rapid recovery, decreased perioperative pain, minimal blood loss, earlier mobilization and decreased hospital length of stay. Overall this allows the athlete to start therapy earlier and return to competition sooner and at his/her pre-operative competitive level. The described MIS repair technique outcomes are similar to those that have been reported in the literature and have allowed a high rate of return to athletics in high performing patients; critical to their quality of life.

A novel method of spinopelvic ring reconstruction after partial sacrectomy for a chondrosarcoma is described. Chondrosarcoma is one of the most common primary malignant bone tumors, and en bloc resection is the mainstay of treatment. Involvement of the pelvis as well as the sacrum and lumbar spine can result in a technically difficult challenge for en bloc resection and for achievement of appropriate load-bearing reconstruction. After en bloc resection in their patient, the authors achieved reconstruction with a rod and screw construct including vascularized fibula graft as the main strut from the lumbar spine to the pelvis. Additionally, a cadaveric allograft strut was used as an adjunct for the pelvic ring. This is similar to a modified Galveston technique with vascularized fibula in place of the Galveston rods. The vascularized fibula provided appropriate biomechanical support, allowing the patient to return to independent ambulation. There was no tumor recurrence; neurological status remained stable; and the allograft construct integrated well and even increased in size on CT scans and radiographs in the course of a follow-up longer than 7 years.

BACKGROUND:Cerebrospinal fluid (CSF) leakage is a complication of intradural spinal surgery and is associated with poor wound healing and infection. The incidence of CSF leak is reported at ∼16% in adults, but little information is available in children. PURPOSE/OBJECTIVE:The aim of this study is to determine the CSF leak rate and predisposing factors after intradural pediatric spinal surgeries. METHODS:This study was a retrospective chart review of 638 intradural spinal operations at BC Children's Hospital. CSF leak was defined as pseudomeningocele or CSF leak through incision. Primary operations to untether lipomyelomeningoceles, myelomeningocele/meningocele closure, and Chiari decompressions were excluded. RESULTS:CSF leaks occurred in 7.1%, with 3% having overt CSF leaks through skin (OCSF leak). CSF leaks, specifically OCSF leaks, were associated with postoperative wound infection (P = 0.0016). Sixteen of 45 cases of CSF leak required reoperation. The type of dural suture used, site of operation, or use of fibrin glue did not affect CSF leak rates. Previous spinal surgery (P < 0.0001), use of dural graft (P = 0.0043), method of dural suturing (P = 0.0023), and procedure performed (P < 0.001) were associated with postoperative CSF leakage. Patients with CSF leak were older than those without leak (98 vs. 72 months, P = 0.002). CONCLUSIONS:Our results provide evidence on intraoperative factors that may predispose to CSF leaks after spinal intradural surgery and may help guide surgical practice. This study confirms that the pediatric population shares many of the same risk factors for CSF leak as in adult populations. Further research is needed to explain how specific factors are associated with CSF leaks.

INTRODUCTION/BACKGROUND:Sacral agenesis is a congenital condition associated with multiple orthopedic, spinal, abdominal and thoracic organ deformities. Meningocele is commonly found among patients with sacral agenesis. DESCRIPTION/METHODS:We present the first case in the literature describing a delayed presentation of terminal (posterior) meningocele in an adult patient born with sacral agenesis. CONCLUSION/CONCLUSIONS:Surgical repair was performed and is the best treatment option for significantly large lesions, with postoperative CSF leak being the main complication.

Nitric oxide produced by inducible nitric oxide synthase (iNOS) contributes importantly to acute lung injury (ALI), but the specific contribution of neutrophil iNOS has not been defined. Thus, we defined the role of neutrophils and specifically neutrophil iNOS in a murine model of septic ALI. Four hours after cecal ligation/perforation, ALI was characterized by increases in pulmonary neutrophil infiltration (tissue myeloperoxidase activity, bronchoalveolar lavage neutrophils), microvascular leak of Evans blue (EB) dye-labeled albumin, and oxidant stress (8-isoprostane levels). Septic ALI was neutrophil dependent, as pretreatment with anti-CD18 before cecal ligation/perforation significantly (P < 0.05) attenuated septic increases in pulmonary myeloperoxidase (39 ± 11 vs. 85 ± 14 mU/mg protein), bronchoalveolar lavage neutrophils (0.5% ± 0.2% vs. 2.1% ± 0.6%), microvascular EB-albumin leak (1.3 ± 0.3 vs. 2.6 ± 0.7 μg EB/g per minute), and 8-isoprostane content (74 ± 15 vs. 115 ± 16 pg/mg protein). The role of neutrophil iNOS was assessed by creation of neutrophil-iNOS chimeric mice: iNOS(+/+) versus iNOS(-/-) mice were bone marrow depleted by irradiation and selectively reconstituted with iNOS(+/+) versus iNOS(-/-) neutrophils. Cecal ligation/perforation resulted in significant septic ALI in + to - neutrophil-iNOS chimeric mice (iNOS(+/+) neutrophils in iNOS(-/-) mice), but not in - to + neutrophil depleted-reconstituted mice (iNOS(-/-) neutrophils in iNOS(+/+) mice). There were no significant differences between iNOS(+/+) and iNOS(-/-) neutrophils in phagocytosis, respiratory burst, or CD11a/b/CD18 surface expression, although septic shedding of CD62L was blunted in iNOS(-/-) neutrophils. Neutrophil iNOS contributes importantly to murine septic ALI in vivo, but not simply through a change in neutrophil phenotype. We speculate that neutrophil iNOS may modulate neutrophil-endothelial interactions in complex fashion, including regulation of transendothelial neutrophil migration and pulmonary neutrophil infiltration.

INTRODUCTION/BACKGROUND:Surgical activity is probably the most important component of surgical training. During the first year of surgical residency, there is an early opportunity for the development of surgical skills, before disparities between the skill sets of residents increase in future years. It is likely that surgical skill is related to operative volumes. There are no published guidelines that quantify the number of surgical cases required to achieve surgical competency. The aim of this study was to describe the current trends in surgical activity in a recent cohort of first-year Canadian neurosurgical trainees. METHODS:This study utilized retrospective database review and survey methodology to describe the current state of surgical training for first-year neurosurgical trainees. A committee of five residents designed this survey in an effort to capture factors that may influence the operative activity of trainees. RESULTS:Nine out of a cohort of 20 first-year Canadian neurosurgical trainees that began training in July of 2008 participated in the study. The median number of cases completed by a resident during the initial three month neurosurgical rotation was 66, within which the trainee was identified as the primary surgeon in 12 cases. Intracranial hemorrhage and cerebrospinal fluid diversion procedures were the most common operations to have the trainee as primary surgeon. CONCLUSION/CONCLUSIONS:Based on this pilot study, it appears that the operative activity of Canadian first-year residents is at least equivalent to the residents of other studied training systems with respect to volume and diversity of surgical activity.