Enrico Tessitore

Clinically relevant complications related to pedicle screw placement in thoracolumbar surgery and their management: a literature review of 35,630 pedicle screws

OBJECT The technique of pedicle screw insertion is a mainstay of spinal instrumentation. Some of its potential complications are clinically relevant and may require reoperation or further postoperative care. METHODS A literature search was performed using MEDLINE (between 1999 and June 2011) for studies on pedicle screw placement in thoracolumbar surgery. The authors included randomized controlled trials, case-control studies, and case series (≥ 20 patients) from the English-, German-, and French-language literature. The authors assessed study type, the number of patients, the anatomical area, the number of pedicle screws, duration of follow-up, type of pedicle screw placement, incidence of complications, and type of complication. The management of specific complications is discussed. RESULTS Thirty-nine articles with 46 patient groups were reviewed with a total of 35,630 pedicle screws. One study was a randomized controlled trial, 8 were case-control studies, and the remaining articles were case series. Dural lesions and irritation of nerve roots were reported in a mean of 0.18% and 0.19% per pedicle screws, respectively. Thirty-two patients in 10 studies (of 5654 patients from all 39 studies) required further revision surgeries for misplaced pedicle screws causing neurological problems. None of the analyzed studies reported vascular complications, and only 2 studies reported visceral complications of clinical significance. CONCLUSIONS Pedicle screw placement in the thoracolumbar region is a safe procedure with an overall high accuracy and a very low rate of clinically relevant complications.

Elevated levels of tumor necrosis factor-alpha in periradicular fat tissue in patients with radiculopathy from herniated disc

Study Design. Case-control study. Objective. To determine whether inflammatory cytokines [tumor necrosis factor (TNF)-&agr;, interleukin (IL)-1&bgr;, IL-6 and IL-8] are elevated in tissues intimately surrounding involved nerve roots of patients suffering from radiculopathy form herniated disc (HD). Summary of Background Data. Proinflammatory cytokines are postulated to play an important role in radiculopathy from HD. Although TNF-&agr; has been found in human HD, it is not known whether TNF-&agr; concentrations are increased in symptomatic patients. Epidural fat (EF) is another tissue in close contact with nerve roots. Histologic modifications of EF have been reported in patients with sciatica but concentrations of inflammatory cytokines have never been studied. Methods. Twenty-three lumbar HD along with adjacent EF (EFHD) were harvested from patients with radicular syndrome. As controls, 14 intervertebral discs (IVDs) and 10 samples of EF (EFC) were obtained from patients without radicular syndrome undergoing spine surgery. Tissue explants were incubated ex vivo for 48 hours and the concentrations of cytokines were measured by ELISA in the supernatants. Results were standardized according to tissue weight. Results. All 4 cytokines were found at higher concentrations in EFHD compared with HD (P < 0.001). TNF-&agr; was the only cytokine found in significantly higher levels in EFHD compared with EFC [median, interquartile range 6.6, (1.6–16.3) pg/mL per milligram of tissue vs. 2.3 (1.3–5.0), P < 0.05] and to subcutaneous fat [0.35 (0–2.28), P < 0.001]. No significant increase of either cytokines was found in HD compared with IVD. Conclusion. Higher concentrations of TNF-&agr; were found in EF from patients with radiculopathy from HD compared with patients suffering from other type of back pain. These results support the role of TNF-&agr; in the pathogenesis of radiculopathy from HD.

Management of benign craniovertebral junction tumors.

Summary. Background: We report our surgical experience in the treatment of fifteen consecutive patients with benign craniovertebral junction tumors, observed from 1993 to 2000 at our department. Method: We treated 7 meningiomas, 3 epidermoids, 3 C1 neurinomas and 2 neurinomas of the lower cranial nerves. Clinical results were evaluated by Karnofsky Performance Scale and all patients underwent preoperative neuroradiological evaluation with CT, MRI and MRA; angiography was not routinely performed and was considered for each individual case. Findings: 11 partial transcondilar and 4 retrocondilar approaches were performed. Total removal was achieved in 11 cases (73,3%) and subtotal removal in 4 patients (26,7%). None of the patients required occipitocervical fusion. Patients were followed for an average period of 24±31 months. Clinical and radiological follow-up showed no recurrence in cases with total removal. In all patients a statistically significant postoperative increase of KPS scores was recorded. The treatment of epidermoid tumors presented particular issues: debulking the lesion, we obtained a surgical window, avoiding a large removal of bone. In Nakasu grade 1 or 2 meningiomas, we carried out total removal by piecemeal resection and without complete condylectomy and bone fixation. Interpretation: The choice of these approaches and the extent of bone resection should be defined according to the tumors location and size. Moreover we emphasize that preoperative neuroradiological evaluations on presumptive tumor type could be helpful to the surgeon in order to tailor the technique to different lesions, providing the required exposure, without unnecessary surgical steps.

Dynamic MR angiography (MRA) of spinal vascular diseases at 3T

Spinal magnetic resonance angiography (MRA) is difficult to perform because of the size of the spinal cord vessels. High-field MR improves resolution and imaging speed. We examined 17 patients with spinal vascular diseases with dynamic contrast-enhanced three-dimensional MR sequences. In three patients, the artery of Adamkievicz could be seen; we could also detect all arteriovenous malformations and dural fistulas. MRA has the potential to replace diagnostic spinal angiography and the latter should be used only for therapeutic purposes.

Influence of cytokine inhibitors on concentration and activity of MMP-1 and MMP-3 in disc herniation

IntroductionSpontaneous resorption of disc herniation (DH) after sciatica is well documented. The matrix metalloproteinases (MMP)-1 and MMP-3 are enzymes potentially involved in this process. Glucocorticoid injections are commonly used for treatment, and other anti-inflammatory molecules like tumor necrosis factor (TNF) inhibitors are under clinical investigation. However, little is known about the effect of these molecules on DH resorption.MethodsDH tissue was harvested from patients undergoing surgery for sciatica. Samples were thoroughly washed. Diced explants were cultured ex-vivo in 1) 0.5 ml Dulbeccos modified Eagles medium (DMEM) 10% fetal calf serum (FCS), (controls), 2) recombinant interleukin 1 receptor antagonist (IL-1Ra), (100 ng/ml), 3) dexamethasone (10E-5 M), or 4) TNF inhibitor monoclonal antibody (10 μg/ml). Supernatants were harvested at 48 hours and frozen. Immunocapture activity assays determined total MMP activity, active MMP levels and pro-MMP levels.ResultsFourteen DH tissue samples were analysed. Levels of all forms of MMP-3 were higher than the respective levels of MMP-1(P < 0.01). In particular, the median (interquartile range [IQR]) total MMP-3 level was 0.97 (0.47 - 2.19) ng/mg of tissue compared to 0.024 (0.01 - 0.07) ng/mg of total MMP-1 level (P < 0.01). Incubation with IL-1Ra, dexamethasone, or TNF inhibitors significantly decreased levels of all forms of MMP-3 (P < 0.05). Dexamethasone significantly decreased the ratio of active MMP-3 to total MMP-3 activity. A significant inhibitory effect of dexamethasone was observed only on active MMP-1, while IL-1 and TNF inhibitor had no significant effect on any form.ConclusionsMMP-3 appears to play a greater role than MMP-1 in DH resorption. Dexamethasone, IL-1-Ra and TNF inhibitor decreased active MMP-3, indicating that the clinical use of these drugs may affect the resorption of DH under certain conditions.

Acute traumatic central cord syndrome: A comprehensive review

Acute traumatic central cord syndrome (ATCCS) is the most common type of incomplete spinal cord injury, characterized by predominant upper extremity weakness, and less severe sensory and bladder dysfunction. ATCCS is thought to result from post-traumatic centro-medullary hemorrhage and edema, or, as more recently proposed, from a Wallerian degeneration, as a consequence of spinal cord pinching in a narrowed canal. Magnetic Resonance Imaging is the method of choice for diagnosis, showing a typical intramedullary hypersignal on T2 sequences. Non-surgical treatment relies on external cervical immobilization, maintenance of a sufficient systolic blood pressure, and early rehabilitation, and should be reserved for patients suffering from mild ATCCS. Surgical management of ATCCS consists of posterior, anterior or combined approaches, in order to achieve spinal cord decompression, with or without stabilization. The benefits of early surgical decompression in the setting of ATCCS remain controversial due to the lack of clinical randomized trials; recent studies suggest that early surgery (less than 72hours after trauma) appears to be safe and effective, especially for patients with evidence of focal anatomical cord compression.

SPECT/CT in differentiation of pseudarthrosis from other causes of back pain in lumbar spinal fusion: report on 10 consecutive cases.

Purpose: SPECT fused with computed tomography (CT) provides a new approach for more accurate diagnosis of pseudathrosis after spinal fusion procedures. The aim of this study was to compare the findings of SPECT fused with CT (SPECT/CT) with those of CT alone for the diagnosis of pseudarthrosis. Materials and Methods: SPECT and CT of 10 consecutive patients with recurrence of back and/or leg pain and with suspicion of pseudarthrosis on conventional radiologic imaging were analyzed retrospectively. All had previously undergone anterior and/or posterior lumbar fusion techniques. Presence of screw loosening, nonunion through or around the cages, and facet joint degeneration were assessed for diagnosis of pseudarthrosis. Based on SPECT/CT scan findings, the decision of surgical reintervention was made on 6 of 10 patients. The clinical follow-up (mean, 15.6 months; range, 5–29 months) was evaluated according to Macnab criteria (excellent, good, fair, poor). Results: All patients showing screw loosening on CT alone showed also an abnormal uptake on SPECT/CT. SPECT/CT did not show abnormal uptake in 3 of 5 patients who had nonunion through/around the cages on CT alone. SPECT/CT was able to show increased uptake in 6 cases in which CT alone did not show facet joint degeneration. Conclusions: In the lumbar spine, SPECT/CT seems to increase specificity for detection of nonunion of interbody devices compared with CT alone. It is more sensitive than CT to detect facet joint degeneration, and it can detect screw loosening as well as CT. These findings can be helpful for surgeons in planning appropriate surgical revision strategy.

Clinically relevant complications related to posterior atlanto-axial fixation in atlanto-axial instability and their management

BACKGROUND The Magerl transarticular technique and the Harms-Goel C1 lateral mass-C2 isthmic screw technique are the two most commonly used surgical procedures to achieve fusion at C1-C2 level for atlanto-axial instability. Despite recent technological advances with an increased safety, several complications may still occur, including vascular lesions, neurological injuries, pain at the harvested bone graft site, infections, and metallic device failure. METHODS We retrospectively analyzed all patients (n=42 cases) undergoing a Harms-Goel C1-C2 fixation surgery with polyaxial C1 lateral mass screws and C2 isthmic screws at two different institutions between 2003 and 2012 and report clinical and radiological complications. One patient was lost to follow-up. The mean follow-up of the remaining 41 patients was 18.7 months (range 12-90). A clinically relevant complication was defined as a complication determining the onset of a new neurological deficit or requiring the need for a revision surgery. RESULTS A total of 14 complications occurred in 10 patients (24.4% of 41 patients). Greater occipital nerve neuralgia was evident in 4 patients (9.8%). All but one completely resolved at the end of the follow-up. Persistent neck pain was reported by 3 patients (7.3%), hypoesthesia by 1 patient (2.4%), and anesthesia in the C2 area on both sides in 1 patient (2.4%). Furthermore, a superficial, a deep, and a combined superficial and deep wound infection occurred in 1 patient each (2.4%). One patient (2.4%) had pain at the iliac bone graft donor site for several weeks with spontaneous resolution. A posterior progressive intestinal herniation through the iliac scar was seen in 1 case (2.4%), which required surgical repair. No vascular damages occurred. Altogether, 5/41 patients (12.2%) had a clinically relevant complication including 4 patients necessitating a revision surgery at the C1-C2 level (9.8%). CONCLUSIONS Atlanto-axial fixation surgery remains a challenging procedure because of the proximity of important neurovascular structures. Nevertheless, on the basis of our current experience, the C1 lateral mass-C2 isthmic screw technique appears to be safe with a low incidence of clinically relevant complications. Postoperative C2 neuralgia, as the most frequent problem, is due to surgical manipulation during preparation of the C1 screw entry point.

Surgical Resident Education in Noninstrumented Lumbar Spine Surgery: A Prospective Observational Study with a 4.5-Year Follow-Up

OBJECTIVE To review the outcomes of noninstrumented lumbar spine surgery performed by trainees as primary operators versus the outcomes of surgery performed by board-certified faculty neurosurgeons. METHODS This prospective observational study involved patients undergoing noninstrumented surgery for lumbar disc herniation or lumbar spinal stenosis with a 4.5-year follow-up. Teaching cases (patients were operated on by neurosurgical residents in training) and nonteaching cases (patients were operated on by board-certified faculty neurosurgeons) were reviewed. Back and leg pain on a visual analog scale, functional disability using the Roland Morris Disability Questionnaire and Oswestry Disability Index, and health-related quality of life (HRQOL) using the 12-Item Short Form Survey and EuroQol 5D were assessed, and reoperations since the index surgery were recorded. RESULTS Questionnaires were returned by 30 patients operated on by residents and 74 patients operated on by board-certified faculty neurosurgeons. On the 12-Item Short Form Survey physical component scale metric, teaching cases were 70% as likely as nonteaching cases (odds ratio = 0.70, 95% confidence interval = 0.25-1.98, P = 0.585) to achieve a favorable HRQOL response to surgery. Visual analog scale measures of back and leg pain were similar for teaching and nonteaching cases. The same was true for functional disability as measured by the Roland Morris Disability Questionnaire and Oswestry Disability Index and for HRQOL measured by the EuroQol 5D. The reoperation rate 4.5 years after the index surgery was also similar for both groups (∼ 10% for both groups). CONCLUSIONS The global outcome, as measured by HRQOL response after a mean follow-up of 4.5 years, was similar for teaching and nonteaching cases. Patients from both groups scored virtually equal results on various pain, functional, and HRQOL metrics, and the reoperation rate was similar.

Constipation after thoraco-lumbar fusion surgery

BACKGROUND Thoraco-lumbar posterior fusion surgery is a frequent procedure used for patients with spinal instability due to tumor, trauma or degenerative disease. In the perioperative phase, many patients may experience vomiting, bowel irritation, constipation, or may even show symptoms of adynamic ileus possibly due to immobilization and high doses of opioid analgesics and narcotics administered during and after surgery. METHODS Retrospective single-center study on patients undergoing thoraco-lumbar fusion surgery for degenerative lumbar spine disease with instability in 2012. Study groups were built according to presence/absence of postoperative constipation, with postoperative constipation being defined as no bowel movement on postoperative days 0-2. RESULTS Ninety-nine patients (39 males, 60 females) with a mean age of 57.1 ± 17.3 years were analyzed, of which 44 patients with similar age, gender, BMI and ASA-grades showed constipation (44.4%). Occurrence of constipation was associated with longer mean operation times (247 ± 62 vs. 214 ± 71 min; p=0.012), higher estimated blood loss (545 ± 316 vs. 375 ± 332 ml; p<0.001), and higher mean morphine dosages in the postoperative days 0-7 (the difference being significant on postoperative days 1 (48 mg vs. 30.9 mg, p=0.041) and 2 (43.2mg vs. 29.1mg, p=0.028). The equivalence dose of morphine administered during surgery was similar (339 ± 196 vs. 285 ± 144 mg; p=0.286). The use of laxatives in the postoperative days 0-7 was generally high in both study groups, while it was more frequent in patients experiencing constipation. One patient with constipation developed a sonographically confirmed paralytic ileus. Patients with constipation showed a tendency toward longer postoperative hospitalization (7.6 vs. 6.7 days, p=0.136). CONCLUSIONS The rate of constipation was high after thoraco-lumbar fusion surgery. Moreover, it was associated with longer surgery time, higher blood loss, and higher postoperative morphine doses. Further trials are needed to prove if the introduction of faster and less invasive surgery techniques may have a positive side effect on bowel movement after spine surgery as they may reduce operation times, blood loss and postoperative morphine use.