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Ketan R. Bulsara, Joel Johnson and Alan T. Villavicencio

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Alan T. Villavicencio, Sigita Burneikiene, Ketan R. Bulsara and Jeffrey J. Thramann

Object

Percutaneous kyphoplasty is an established method for the treatment of pathological vertebral compression fractures (VCFs). This procedure is usually performed with the aid of biplanar fluoroscopic image guidance. There are currently no published clinical studies in which the use of three-dimensional (3D) image guidance to facilitate this technique has been evaluated. The purpose of this study was to evaluate the efficacy of isocentric fluoroscopy-based navigation for the kyphoplasty procedure, with special reference to operating time and the amount of radiation exposure.

Methods

A prospective clinical study was performed in which 11 consecutive patients with painful pathological VCFs that did not respond to conservative treatment underwent the kyphoplasty procedure. During this procedure, cannulation of the pedicle and vertebral body was performed with the aid of isocentric 3D fluoroscopy visualization. Total operating time and intraoperative fluoroscopy time for this group was compared with a cohort of nine patients who underwent the procedure prior to the availability of isocentric fluoroscopy (only biplanar fluoroscopy was used). Possible complications such as cement extravasations were evaluated during the procedure and on postoperative computerized tomography scans.

The mean duration of surgery for the 3D isocentric fluoroscopic guidance group was 60 minutes (range 36–89 minutes) for one-level and 68.5 minutes (range 65–75 minutes) for two-level cases. Because of a learning curve with the equipment, the operating time for the initial cases was significantly longer than with the later ones. Even with the initial cases included, the mean operating time was shorter compared with the biplanar fluoroscopy-assisted procedures, which averaged 69.2 minutes (range 44–113 minutes) for one-level procedures. This difference was not statistically significant. The mean fluoroscopy exposure time was 41.3 seconds (range 25–62 seconds) in the isocentric fluoroscopy-assisted procedures, with an additional 40 seconds of fluoroscopy time used for the 3D fluoroscopy “spin,” compared with 293.2 seconds (range 180–400 seconds) in the biplanar fluoroscopy-assisted procedures. The difference was statistically significant (p = 0.02). All pedicles were accessed without difficulty and no complications were encountered in either group of patients.

Conclusions

The main advantage of isocentric fluoroscopy is the significant reduction in radiation exposure for the patient and surgical staff without an increase in the mean operating time. This technique is a significant advancement over biplanar fluoroscopy in this setting.

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Alan T. Villavicencio, Sigita Burneikienë, Theresa D. Hernández and Jeff Thramann

Object

As the sport of triathlon has continued to grow, increasing numbers of triathletes have presented in the neurosurgery clinics with various spinal disorders. This epidemiological study was undertaken to establish the lifetime incidence of neck and back pain, to gauge the prevalence of discogenic pain, and to identify risk factors among triathletes in the Boulder, Colorado, area.

Methods

A live online questionnaire was developed that was used to collect information about physical characteristics, training habits, athletic status, number of races completed, and back pain among triathletes. The incidence of cervical and/or lumbar discogenic back pain was defined according to the duration of symptoms for the most recent pain episode.

The lifetime incidence of low-back pain was 67.8%, with 23.7% of cases possibly being discogenic in origin. The number of triathlons in which the respondents had participated and the presence of previous sports-related injuries were predictive of low-back pain (p = 0.02 and p < 0.00001, respectively). The lifetime incidence of neck pain was 48.3%, with 21.4% of cases being consistent with intervertebral disc involvement. The number of previous sports-related injuries was predictive of neck pain (p < 0.00001), and a strong tendency toward neck pain was observed for athletes with more total years of participation in sports (p = 0.06).

Conclusions

The two main risk factors for long-term spinal problems include sports-related injuries and overuse. The study results definitely support the influence of both mechanisms for low-back pain. Neck pain was associated with an injury event, and a strong (although not statistically significant) tendency toward neck pain was observed in respondents with overuse injuries.

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Alan T. Villavicencio, E. Lee Nelson, Vinod Kantha and Sigita Burneikiene

OBJECTIVE

Opioid analgesics have become some of the most prescribed drugs in the world, despite the lack of long-term studies evaluating the benefits of opioid medications versus their risks associated with chronic use. In addition, long-term opioid use may be associated with worse long-term clinical outcomes. The primary objective of this study was to evaluate whether preoperative opioid use predicted inferior clinical outcomes among patients undergoing transforaminal lumbar interbody fusion (TLIF) for symptomatic lumbar degenerative disc disease.

METHODS

The authors of this observational study prospectively enrolled 93 patients who underwent 1-level to 2-level TLIFs in 2011–2014; the patient cohort was divided into 2 groups according to preoperative opioid use or no such use. Visual analog scale (VAS) scores for low-back pain and leg pain, Oswestry Disability Index scores, and the scores of the mental component summary (MCS) and physical component summary (PCS) on the 36-Item Short Form Health Survey were used to assess pain, disability, and health-related quality of life outcomes, respectively. The clinical scores for the 2 groups were determined preoperatively and at a 12-month follow-up examination.

RESULTS

In total, 60 (64.5%) patients took prescribed opioid medications preoperatively. Compared with those not taking opioids preoperatively, these patients had significantly higher VAS scores for low-back pain (p = 0.016), greater disability (p = 0.013), and lower PCS scores (p = 0.03) at the 12-month follow-up. The postoperative MCS scores were also significantly lower (p = 0.035) in the opioid-use group, but these lower scores were due to significantly lower baseline MCS scores in this group. A linear regression analysis did not detect opioid dose–related effects on leg and back pain, disability, and MCS and PCS scores, suggesting that poorer outcomes are not significantly correlated with higher opioid doses taken by the patients.

CONCLUSIONS

The use of opioid medications to control pain before patients underwent lumbar fusion for degenerative lumbar conditions was associated with less favorable clinical outcomes postoperatively. This is the first study that has demonstrated this association in a homogeneous cohort of patients undergoing TLIF; this association should be studied further to evaluate the conclusions of the present study.

Clinical trial registration no.: NCT01406405 (clinicaltrials.gov)

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John K. Stokes, Alan T. Villavicencio, Paul C. Liu, Robert S. Bray and J. Patrick Johnson

Object

Surgical treatment of atlantoaxial instability has evolved to include various posterior wiring techniques including Brooks, Gallie, and Sonntag fusions in which success rates range from 60 to 100%. The Magerl–Seemans technique in which C1–2 transarticular screws are placed results in fusion rates between 87 and 100%. This procedure is technically demanding and requires precise knowledge of the course of the vertebral arteries (VAs). The authors introduce a new C1–2 fixation procedure in which C-1 lateral mass and C-2 pedicle screws are placed that may have advantages over C1–2 transarticular screw constructs.

Methods

A standard posterior C1–2 exposure is obtained. Polyaxial C-2 pedicle screws and C-1 lateral mass screws are placed bilaterally. Rods are connected to the screws and secured using locking nuts. A cross-link is then placed. Fusion can be performed at the atlantoaxial joint by elevating the C-2 nerve root.

The technique for this procedure has been used in four cases of atlantoaxial instability at the author's institution. There have been no C-2 nerve root– or VA-related injuries. No cases of construct failure have been observed in the short-term follow up period.

Conclusions

Atlantoaxial lateral mass and axial pedicle screw fixation offers an alternative means of achieving atlantoaxial fusion. The technique is less demanding than that required for transarticular screw placement and may avoid the potential complication of VA injury. The cross-linked construct is theoretically stable in flexion, extension, and rotation. Laminectomy or fracture of the posterior elements does not preclude use of this fixation procedure.

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Alan T. Villavicencio, Theresa D. Hernández, Sigita Burneikiene and Jeff Thramann

Object

The sport of triathlon is very physically demanding and has experienced rapid growth in recent years. The number of triathletes seen for spine disorders at neurosurgery clinics is increasing. Neck pain and overuse injuries have not been adequately studied in multisport athletes. The authors undertook an epidemiological study to establish the lifetime incidence of neck pain and the prevalence of possible discogenic pain, and to identify risk factors among triathletes in the Boulder, Colorado area.

Methods

An online questionnaire was developed to collect information about physical characteristics, training habits, athletic status, number of races completed, and neck pain among triathletes. The incidence of possible cervical discogenic pain was defined according to the duration of symptoms for the most recent pain episode.

Results

One hundred and sixty-four athletes responded to the questionnaire. The lifetime incidence of neck pain was 47.6% (78 athletes), with 15.4% possibly being of discogenic origin based on the duration of symptoms. Approximately 64% of responding athletes reported that their neck pain was sports related. Although the number of previous triathlons was not predictive of neck pain, total years in the sport (p = 0.029) and number of previous sports-related injuries (p < 0.0001) were.

Conclusions

Two major risk factors for long-term spinal problems in triathletes are sports-related injuries and overuse. This report is one of the first comprehensive studies of neck pain and overuse injury in multisport athletes.

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Alan T. Villavicencio, Sigita Burneikiene, E. Lee Nelson, Ketan R. Bulsara, Mark Favors and Jeffrey Thramann

Object. Recombinant human bone morphogenetic protein—2 (rhBMP-2) is being increasingly used for spinal fusion. There are few data regarding its clinical safety, effectiveness, and clinical outcome when applied on an absorbable collagen sponge (ACS) in conjunction with allograft for transforaminal lumbar interbody fusion (TLIF).

Methods. Seventy-four consecutive patients undergoing TLIF for degenerative disc disease were divided into five groups depending on whether the patient underwent a minimally invasive or open approach, as well as the number of spinal levels surgically treated. Surgery-related data, fusion results, complications, and clinical outcome were evaluated. The mean follow-up duration was 20.6 months (range 14–28 months). The radiographic fusion rate was 100% at 12 and 24 months after the surgery. No bone overgrowth or other complications related to BMP use were demonstrated.

Conclusions. Analysis of the results demonstrated that TLIF combined with a BMP-2—soaked ACS is a feasible, effective, and safe method to promote lumbar fusion. There were no significant intergroup differences in clinical outcome between patients who underwent open compared with minimally invasive procedures. Patient satisfaction rates, however, were higher in the minimally invasive procedure group. The efficacy of BMP-2 was not dependent on which approach was used or the number of spinal levels that were treated.

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Matthew J. McGirt, Alan T. Villavicencio, Ketan R. Bulsara, Henry S. Friedman and Allan H. Friedman

✓ Adjuvant use of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) wafers with surgical resection is becoming common for the treatment of malignant gliomas. Cyst formation in the tumor resection cavity is a recently described complication associated with the use of BCNU wafers. There is currently no report in which successful management of this complication without additional surgical intervention is described.

The authors describe four patients in whom postoperative cysts developed in the tumor resection cavity after placement of BCNU wafers. These include a 38-year-old man with a left frontoparietal tumor, a 48-year-old man with a right frontal lobe tumor, a 78-year-old man with a left parietooccipital tumor, and a 61-year-old woman with a left frontotemporal tumor. Histopathological studies of biopsy samples revealed malignant glioma in each patient. All four patients had unremarkable perioperative courses, were discharged within 3 to 8 days of surgery, and subsequently returned with acute neurological deterioration. Follow-up magnetic resonance (MR) imaging demonstrated cyst formation with significant mass effect at the previous resection site. Three patients were treated with high-dose dexamethasone and returned to their neurological baseline over an 8-day period. The fourth patient improved after surgical drainage and biopsy sampling of the cyst, which revealed no evidence of infection or recurrent tumor, but again sought medical care 2 weeks later with cyst recurrence necessitating high-dose steroid therapy. On MR images at least a 30% reduction in cyst size was demonstrated in all four patients, each of whom remained clinically stable at 2, 6, 6, and 4 months of follow-up review.

Neurosurgeons should be aware of the potential for postoperative cyst formation accompanied by clinically significant mass effect after BCNU wafer implantation, as well as the potential for successful nonsurgical management leading to clinical and radiological improvement.

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Alan T. Villavicencio, Rod J. Oskouian, Cliff Roberson, John Stokes, Jongsoo Park, Christopher I. Shaffrey and J. Patrick Johnson

Object

Metastatic spinal tumors continue to represent a major problem for patients and treating physicians. The purpose of this study was to assess quantitatively the functional outcome, quality of life, and survival rates of patients after major reconstructive spine surgery.

Methods

A prospective database was established and 58 patients were identified who had undergone thoracolum-bar vertebral reconstruction for metastatic spinal tumors between March 1993 and October 1999. Surgical indications included disabling pain (92%) and/or progressive neurological dysfunction (60%).

Forty-nine patients (85%) had clinical improvement in pain as determined based on the Oswestry pain scale (p < 0.05); 60% demonstrated improvement in their neurological status. The mean neurological improvement in Frankel grade was 1.2 (p < 0.05). The 12-month survival rate was 65%, and all patients who were ambulatory after surgery remained so until the time of death. Instrumentation failure requiring repeated operation occurred in two patients (3.5%), and in 12 patients (21%) local tumor recurrence necessitated repeated surgery. There were no cases of neurological deficit or death related to surgery.

Conclusions

Major anterior thoracolumbar vertebral reconstruction is an effective treatment for local tumor control. More importantly, the authors have demonstrated that surgical treatment can significantly improve the quality of life by improvement of pain control and maintenance of ambulation during the patient's remaining life span.

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Tomislav Smoljanovic, Slobodan Vukicevic and Marko Pecina