Biomedical subjects

Robert E Isaacs

Publications and source records attributed to Robert E Isaacs.

7 recordsLinked to original sources

PubMed2006

Placement of percutaneous pedicle screws without imaging guidance.

Pedicle screw (PS) instrumentation provides an exceptionally rigid construct to promote fusion in cases of spinal trauma and degenerative disease. Although the safety of traditional open techniques for PS placement has been well documented, there are no large series in the literature in which the safety of percutaneously placed PSs has been examined. Because the advantages of minimally invasive spine surgery are becoming more widely recognized, especially in regard to the lessening of morbidity caused by pain and blood loss, there will be a greater demand for spine surgeons to place PSs percutaneously. During a 2-year period, the authors placed 287 PSs percutaneously with the aid of intraoperative fluoroscopy. Only one of these screws was later found to have breached the spinal canal, yielding a breach rate of 0.35% for percutaneously placed PSs (one of 287).

Bone Screws↗

PubMed2006

Minimally invasive fusion and fixation techniques.

Instrumented fusion plays an important role in treating a variety of degenerative and traumatic diseases of the spine. Traditional open techniques have been associated with a high degree of approach-related morbidity because of muscle retraction and blood loss. A variety of minimally invasive techniques have been developed for instrumentation of the entire spine. Advances in our understanding of the cellular and molecular mechanisms for stable bony fusion should promote the use of even less invasive techniques in the future.

Humans↗

PubMed2006

Complications associated with minimally invasive decompression for lumbar spinal stenosis.

OBJECTIVE: Surgical strategies for the decompression of lumbar spinal stenosis have evolved to include minimally invasive techniques providing for adequate and safe decompression while reducing perioperative morbidity. Retrospective case series analysis of 220 consecutive patients with lumbar spinal stenosis who underwent microscopic or microendoscopic minimally invasive decompression was performed. The objective was to evaluate the risks associated with performing a minimally invasive decompression for spinal stenosis in a large group of patients. METHODS: Two hundred twenty patients with symptomatic neurogenic claudication from lumbar spinal stenosis failing nonoperative treatment received a minimally invasive decompression surgery. Intraoperative data, postoperative data through hospital discharge, and clinical follow-up were analyzed. RESULTS: The average age was 74.2 years (range 49-98 years). There were 379 spinal levels decompressed in 220 patients. Sixty-nine patients (31.4%) had a grade 1 degenerative spondylolisthesis. One hundred sixty-eight patients (76%) received spinal anesthesia, and 52 received general anesthesia. Eighty-seven patients (40%) had a preoperative American Society of Anesthesiologists score of 3 or 4. Average operative blood loss was 92 mL. There were 17 intraoperative durotomies (4.5% rate). The average length of stay before discharge was 1.2 days. Ten patients went to inpatient rehabilitation at discharge. One hundred ninety-four patients (88.2%) were discharged within 24 hours. There were five readmissions within the first month after discharge, four of those for medical complications. There were 24 minor complications and 14 major complications. Forty-two patients (19%) took no oral or parenteral narcotic pain medications in the postanesthesia to discharge period. CONCLUSION: Minimally invasive decompression strategies for spinal stenosis seem consistently to result in short hospital lengths of stay, minimal requirements for narcotic pain medications, and a low rate of readmission and complications.

Aged↗

PubMed2005

Thoracic microendoscopic discectomy: a human cadaver study.

STUDY DESIGN: Feasibility analysis of percutaneous posterolateral thoracic microendoscopic discectomy in a human cadaver model. OBJECTIVE: To describe a new, minimally invasive, posterolateral approach to the thoracic spine for the treatment of disc herniations. SUMMARY OF BACKGROUND: Thoracoscopic discectomy offers surgeons direct ventral access to thoracic disc herniations but requires entry into the chest. Many surgeons favor a posterolateral approach to the thoracic spine, thereby avoiding morbidity associated with entry into the thoracic cavity. By adapting minimal access surgical techniques to the thoracic spine, effective treatment of thoracic disc herniations should be possible and may help expedite recovery. METHODS: Two cadaveric human torsos were used. Using simple adaptations of our standard lumbar microendoscopic discectomy technique, endoscopic discectomies were performed throughout the mid and lower thoracic spine. Operative time was recorded. The extent of the discectomy as well as the extent of bony removal was evaluated using computed tomography myelography. RESULTS: Nine discectomies were performed in two cadaveric specimens, from T5-T6-T9-T10. Operative times ranged from 46 to 77 minutes (mean 60 minutes). The procedure required removing 3.4 mm (+/-1.9 mm) of the ipsilateral facet, which amounted to 35.4% (+/-17.5%) of the facet complex. Canal decompression averaged 73.5% (+/-7.9%). CONCLUSIONS: Thoracic microendoscopic discectomy allows for a posterolateral approach to thoracic disc herniation without entry into the chest cavity that consistently gives access to the majority of the canal while requiring only a minimal amount of bone removal. This technique provides an approach angle similar to that obtained with other posterolateral discectomy techniques while limiting the morbidity associated with exposure.

Arthroscopy↗

PubMed2005

Minimally invasive microendoscopy-assisted transforaminal lumbar interbody fusion with instrumentation.

OBJECT: The authors have developed a novel technique for percutaneous fusion in which standard microendoscopic discectomy is modified. Based on data obtained in their cadaveric studies they considered that this minimally invasive interbody fusion could be safely implemented clinically. The authors describe their initial experience with a microendoscopic transforaminal lumbar interbody fusion (METLIF) technique, with regard to safety in the placement of percutaneous instrumentation, perioperative morbidity, and early postoperative results. METHODS: The METLIF procedure was performed unilaterally in 20 patients with single-level lumbar spondylolisthesis or pure mechanical back pain with endoscopic assistance, hemilaminectomy, unilateral facetectomy, and microdiscectomy. Two interbody grafts were placed via the lateral exposure of the disc space. Bilateral percutaneous pedicle screws were then inserted. Compared with patients who had undergone single-level posterior LIF at the same institutions, intraoperative blood loss, hospital length of stay (LOS), and postoperative narcotic agent use were significantly lower in the METLIF group. The mean LOS for the percutaneous fusion group was 3.4 days (5.1 days in those who underwent PLIF; p < 0.02). There have been no procedure-related complications in this series to date. CONCLUSIONS: The METLIF technique provided an option for percutaneous interbody fusion similar to that in open surgery while minimizing destruction to adjacent tissues. This technique was safe and exhibited a trend toward decreased intraoperative blood loss, postoperative pain, total narcotic use, and the risk of transfusion.

Adult↗

PubMed2003

Microendoscopic discectomy for recurrent disc herniations.

OBJECT: The use of microendoscopic discectomy (MED) for the treatment of primary lumbar disc herniations has become fairly well accepted; its role in recurrent disc herniations is less clear. The reluctance of many surgeons to use this technique stems, in part, from the concern of undertaking an endoscopic discectomy in a patient in whom the anatomy is distorted from a previous operation. It appears counterintuitive to operate through a limited working area when the traditional open approach for recurrence favors wider exposure of the surgical field. Given that operating on previously exposed tissue can be associated with even greater morbidity than on virginal tissue, the authors describe their experience with performing MED for recurrent disc herniation. METHODS: Unilateral MED was performed in patients with classic symptoms of lumbar radiculopathy, a previous operation at that level, and findings of recurrent disc herniation on magnetic resonance imaging. The approach was similar to a standard MED. Aided by fluoroscopic guidance, a working cannula was docked on the laminofacet junction at the level of the nerve root, with care taken to ensure a slightly more lateral initial trajectory. A good decompression of the nerve root could then be achieved through the use of the endoscope with preservation of the paraspinous musculature and much of the remaining facet capsule. Ten consecutive patients undergoing the procedure were analyzed prospectively and compared with the previous 25 who underwent routine single-level MED. Use of the MED technique provided excellent visualization and decompression of the nerve root; no conversions to open procedures were necessary in either group. The average operative time in the experimental group was 98.5 minutes, with a mean blood loss of 33 ml and an approximate hospital stay of 7.3 hours. In this respect, there was no statistical difference between the two groups (analysis of variance, p = 0.39, 0.68, and 0.51, respectively). There was one cerebrospinal fluid leak in each group. CONCLUSIONS: Microendoscopic discectomy for recurrent disc herniation can be safely performed without an increase in surgery related morbidity.

Adult↗

PubMed2002

Microendoscopic lumbar discectomy: technical note.

OBJECTIVE: The microendoscopic discectomy (MED) technique was initially developed in 1997 to treat herniated lumbar disc disease. Since then, thousands of cases have been successfully performed at more than 500 institutions. This article discusses the technical aspects of this procedure and presents a consecutive case series. METHODS: A total of 150 consecutive patients underwent MED. MED is performed by a muscle-splitting approach using a series of tubular dilators with consecutively increasing diameters. A tubular retractor is then inserted over the final dilator, and a specially designed endoscope is placed inside the tubular retractor. The microdiscectomy is performed endoscopically while the surgeon views the procedure on a video monitor. RESULTS: Clinical outcomes were determined using a modified MacNab criteria, which revealed that 77% of patients had excellent, 17% had good, 3% had fair, and 3% had poor outcomes. The average hospital stay was 7.7 hours. The average return to work period was 17 days. Complications primarily included dural tears, which occurred in 8 patients (5%) and were seen early on in the patient series. Complication rates diminished as the surgeon's experience with this technique increased. CONCLUSION: MED for lumbar herniated disc disease can be performed safely and effectively, resulting in a shortened hospital stay and faster return to work; however, there is a learning curve to this procedure.

Adult↗