Robot guidance for percutaneous minimally invasive placement of pedicle screws for pyogenic spondylodiscitis is associated with lower rates of wound breakdown compared to conventional fluoroscopy-guided instrumentation.

Postoperative wound healing can pose a problem in patients undergoing instrumented surgery for pyogenic spondylodiscitis. Robotic guidance allows the minimally invasive placement of pedicle screws in the thoracolumbar spine. We assessed whether using this technique to perform minimally invasive surgery had an impact on wound healing in patients with pyogenic spondylodiscitis when compared to conventional open fluoroscopy-guided surgery. We reviewed charts of 206 consecutive patients who underwent instrumentation for pyogenic spondylodiscitis. The need for wound revision was the primary outcome measure. Patient variables and comorbidities as well as surgical technique (robotic versus fluoroscopy-guided) were analyzed. We also compared fluoroscopy times between the two groups. Multivariate regression analysis was performed to identify predictors of wound breakdown. A total of 206 patients underwent surgery for spondylodiscitis. Robotic surgical assistance was used for percutaneous instrumentation in 47.6% of cases (n = 98). Wound healing problems requiring revision occurred in 30 out of 206 patients (14.6%). Univariate analysis revealed a potential association of wound breakdown with (1) robotic technique, (2) age > 70 years, and (3) the presence of methicillin-resistant Staphylococcus aureus. After multivariate correction however, only robotic technique retained significance with an odds ratio of 0.39 (CI 95% 0.16-0.94; p = 0.035). Wound revision was required in eight out of 98 patients (8.1%) in the robot group and 22/108 (20%) in the conventional surgery group. Fluoroscopy times were significantly lower in the robot group with a mean of 123 ± 86 s in comparison with a mean of 157 ± 99 s in the conventional group (p = 0.014). While initially designed to improve the accuracy of pedicle screw placement, robot-assisted minimally invasive technique had a tangible effect on both radiation exposure and the rate of wound breakdown in patients with pyogenic spondylodiscitis in our large single-center study.

Predictors of ventricular tension pneumocephalus after posterior fossa surgery in the sitting position.

BACKGROUND: Ventricular pneumocephalus is a rare but potentially life-threatening complication of cranial surgery in the sitting position. OBJECTIVE: The objective of the study is to assess the incidence and risk factors of postoperative ventricular pneumocephalus. METHODS: We performed a retrospective chart review of 307 consecutive patients (147 men, 160 women) treated at our institution by intracranial surgery in the sitting position from January 2010 to October 2014. Ventricular air entrapment with lack of arousal or neurologic deterioration requiring external ventriculostomy (EVD) was defined as ventricular tension pneumocephalus (VTP). Demographic variables were recorded along with radiological and clinical data. The occurrence of pneumocephalus was correlated with patient-related and surgical variables. RESULTS: VTP was observed in 12 cases (3.9%). These patients had higher intraventricular air volumes (48.5 cm3 (CI 95% [29.06-67.86])) compared to asymptomatic patients (7.4 cm3 (CI 95% [5.43-9.48])). Opening of the fourth ventricle was the most potent predictor of VTP (OR = 34.7, CI 95% [4.4-273.5], p = 0.001). In patients undergoing no additional treatment for pneumocephalus, ventricular air volume declined to an average of 41.7% of the initial postoperative volume on postoperative day 3. CONCLUSIONS: Entrapment of intracranial and particularly ventricular air requiring emergent EVD occurred in 3.9% cases of intracranial surgery in the sitting position. Especially the opening of the fourth ventricle was associated with the development of VTP, which should warrant particularly diligent postoperative observation of these patients. In cases without neurological symptoms, the rate of spontaneous air resorption is sufficiently high to warrant expectant management.

Accuracy of robot-guided versus freehand fluoroscopy-assisted pedicle screw insertion in thoracolumbar spinal surgery.

OBJECTIVE The quest to improve the safety and accuracy and decrease the invasiveness of pedicle screw placement in spine surgery has led to a markedly increased interest in robotic technology. The SpineAssist from Mazor is one of the most widely distributed robotic systems. The aim of this study was to compare the accuracy of robot-guided and conventional freehand fluoroscopy-guided pedicle screw placement in thoracolumbar surgery. METHODS This study is a retrospective series of 169 patients (83 women [49%]) who underwent placement of pedicle screw instrumentation from 2007 to 2015 in 2 reference centers. Pathological entities included degenerative disorders, tumors, and traumatic cases. In the robot-assisted cohort (98 patients, 439 screws), pedicle screws were inserted with robotic assistance. In the freehand fluoroscopy-guided cohort (71 patients, 441 screws), screws were inserted using anatomical landmarks and lateral fluoroscopic guidance. Patients treated before 2009 were included in the fluoroscopy cohort, whereas those treated since mid-2009 (when the robot was acquired) were included in the robot cohort. Since then, the decision to operate using robotic assistance or conventional freehand technique has been based on surgeon preference and logistics. The accuracy of screw placement was assessed based on the Gertzbein-Robbins scale by a neuroradiologist blinded to treatment group. The radiological slice with the largest visible deviation from the pedicle was chosen for grading. A pedicle breach of 2 mm or less was deemed acceptable (Grades A and B) while deviations greater than 2 mm (Grades C, D, and E) were classified as misplacements. RESULTS In the robot-assisted cohort, a perfect trajectory (Grade A) was observed for 366 screws (83.4%). The remaining screws were Grades B (n = 44 [10%]), C (n = 15 [3.4%]), D (n = 8 [1.8%]), and E (n = 6 [1.4%]). In the fluoroscopy-guided group, a completely intrapedicular course graded as A was found in 76% (n = 335). The remaining screws were Grades B (n = 57 [12.9%]), C (n = 29 [6.6%]), D (n = 12 [2.7%]), and E (n = 8 [1.8%]). The proportion of non-misplaced screws (corresponding to Gertzbein-Robbins Grades A and B) was higher in the robot-assisted group (93.4%) than the freehand fluoroscopy group (88.9%) (p = 0.005). CONCLUSIONS The authors' retrospective case review found that robot-guided pedicle screw placement is a safe, useful, and potentially more accurate alternative to the conventional freehand technique for the placement of thoracolumbar spinal instrumentation.

Robotic versus fluoroscopy-guided pedicle screw insertion for metastatic spinal disease: a matched-cohort comparison.

OBJECTIVE Robot-guided pedicle screw placement is an established technique for the placement of pedicle screws. However, most studies have focused on degenerative disease. In this paper, the authors focus on metastatic spinal disease, which is associated with osteolysis. The associated lack of dense bone may potentially affect the automatic recognition accuracy of radiography-based surgical assistance systems. The aim of the present study is to compare the accuracy of the SpineAssist robot system with conventional fluoroscopy-guided pedicle screw placement for thoracolumbar metastatic spinal disease. METHODS Seventy patients with metastatic spinal disease who required instrumentation were included in this retrospective matched-cohort study. All 70 patients underwent surgery performed by the same team of experienced surgeons. The decision to use robot-assisted or fluoroscopy-guided pedicle screw placement was based the availability of the robot system. In patients who underwent surgery with robot guidance, pedicle screws were inserted after preoperative planning and intraoperative fluoroscopic matching. In the "conventional" group, anatomical landmarks and anteroposterior and lateral fluoroscopy guided placement of the pedicle screws. The primary outcome measure was the accuracy of screw placement on the Gertzbein-Robbins scale. Grades A and B (< 2-mm pedicle breach) were considered clinically acceptable, and all other grades indicated misplacement. Secondary outcome measures included an intergroup comparison of direction of screw misplacement, surgical site infection, and radiation exposure. RESULTS A total of 406 screws were placed at 206 levels. Sixty-one (29.6%) surgically treated levels were in the upper thoracic spine (T1-6), 74 (35.9%) were in the lower thoracic spine, and the remaining 71 (34.4%) were in the lumbosacral region. In the robot-assisted group (Group I; n = 35, 192 screws), trajectories were Grade A or B in 162 (84.4%) of screws. The misplacement rate was 15.6% (30 of 192 screws). In the conventional group (Group II; n = 35, 214 screws), 83.6% (179 of 214) of screw trajectories were acceptable, with a misplacement rate of 16.4% (35 of 214). There was no difference in screw accuracy between the groups (chi-square, 2-tailed Fisher's exact, p = 0.89). One screw misplacement in the fluoroscopy group required a second surgery (0.5%), but no revisions were required in the robot group. There was no difference in surgical site infections between the 2 groups (Group I, 5 patients [14.3%]; Group II, 8 patients [22.9%]) or in the duration of surgery between the 2 groups (Group I, 226.1 ± 78.8 minutes; Group II, 264.1 ± 124.3 minutes; p = 0.13). There was also no difference in radiation time between the groups (Group I, 138.2 ± 73.0 seconds; Group II, 126.5 ± 95.6 seconds; p = 0.61), but the radiation intensity was higher in the robot group (Group I, 2.8 ± 0.2 mAs; Group II, 2.0 ± 0.6 mAs; p < 0.01). CONCLUSIONS Pedicle screw placement for metastatic disease in the thoracolumbar spine can be performed effectively and safely using robot-guided assistance. Based on this retrospective analysis, accuracy, radiation time, and postoperative infection rates are comparable to those of the conventional technique.

Shape of the Spinal Canal Is Not Associated with Success Rates of Microsurgical Unilateral Laminotomy and Bilateral Decompression for Lumbar Spinal Canal Stenosis.

BACKGROUND: Anatomic shape of the spinal canal (oval, round, trefoil) has been reported to predict outcome of bilateral decompression performed in an undercutting technique via unilateral laminotomy in monosegmental lumbar spinal stenosis, with poorest results observed in a trefoil spinal canal, leading to the proposal of using bilateral instead of unilateral laminotomy. The aim of this study was to assess whether this anatomic classification into oval, round, and trefoil shapes is relevant to surgical treatment of lumbar spinal stenosis. METHODS: Retrospective chart review of patients undergoing lumbar decompression surgery was performed. Spinal canal configuration was assessed on preoperative computed tomography based on maximal transverse and anteroposterior diameter, and shapes were classified into oval, round, and trefoil. Associations between spinal canal shape and outcome improvement (aggregate of walking distance and leg pain) were tested. RESULTS: Decompression of 236 lumbar levels was performed in 159 patients (mean age, 73 ± 8 years; mean body mass index, 29 ± 6). Average number of operated segments was 1.3 ± 0.6. Oval configurations were detected in 155 (65%) levels, round configurations were detected in 11 (5%) levels, and trefoil configurations were detected in 70 (30%) levels. Postoperative improvement was recorded in 91.7% of patients. Spinal canal shape had no influence on surgical outcome (oval, area under the curve 0.529, P = 0.672; trefoil, area under the curve 0.500, P = 0.997; round, area under the curve 0.471, P = 0.670). CONCLUSIONS: Spinal canal configuration varies in frequency with lumbar segment. Our results do not support the idea that this anatomic classification, particularly the nomenclature of oval, round, and trefoil, should influence surgical decision making.

Rescue Implantation of Expandable Cages for Severe Osteolysis and Cage Dislocation in the Lumbosacral Junction.

BACKGROUND: Osteolysis and implant loosening are commonly encountered problems after spinal instrumentation. CASE DESCRIPTION: In a patient who had previously undergone a posterior lumbar interbody fusion procedure, fusion did not occur, and a secondary cage dislocation led to an impingement of the L5 nerve root with severe radiculopathy. Revision surgery was performed. Intraoperatively, osteolysis was found to be so severe that conventional cages did not fill the void to allow for sufficient anterior column support. We used expandable transforaminal lumbar interbody fusion cages and implanted them bilaterally to replace the dislodged posterior lumbar interbody fusion cages. Clinical follow-up was uneventful. Imaging performed at 1 year showed satisfactory cage position and fusion. CONCLUSIONS: We propose the use of cages with the ability of ventral distraction in similar rescue interventions with cage dislocation and bone resorption. This may prevent a second surgery via a ventral approach.

Modified method for microvascular anastomosis suturing.

BACKGROUND: Suturing of microvascular anastomosis is still a time-consuming procedure, despite the fact that different techniques and devices were designed to reduce the operation time and increase the patency rate. This paper reports a method for microvascular anastomosis suturing, using foam rubber cylindrical mandrel, which helps to solve the above-stated problems. METHODS: The principle of method is based on running suture, imposed around the foam rubber mandrel. Then the suture is divided into separate stitches. After the visual control of anastomosis lumen knots are tightened. The procedure is the same for front and back parts of anastomosis. RESULTS: Testing of technique in the laboratory showed the possibility of using a single thread per anastomosis and reducing the time for suturing from 17.3 to 15.4 min compared with standard procedure. CONCLUSIONS: Described technique allows surgeon to control the lumen of anastomosis before tightening knots, reduces time of work, and does not increase the cost of operation.

Contralateral delayed epidural hematoma following intracerebral hematoma surgery.

BACKGROUND: Delayed epidural hematoma (EDH) is an uncommon finding in patients after intracranial hematomas evacuation. It occurs in 6.7-7.4% of cases. A total of 29 reports were found in literature. Between them were no cases of delayed contralateral EDH after intracerebral hematoma evacuation. CASE DESCRIPTION: This paper represents a clinical case of a 28-year-old male patient with opened penetrating head injury, who underwent left frontal lobe intracerebral hematoma evacuation and one day later a contralateral EDH was found and successfully surgically treated. CONCLUSION: Contralateral EDH is a life-threatening neurosurgical emergency case, which can occur during first 24 hours after decompressive craniectomy. Control CT scans must be performed next day after the operation to verify and treat contralateral EDH timely.

Posttraumatic delayed subdural tension pneumocephalus.

BACKGROUND: Pneumocephalus is a complication of head injury in 3.9-9.7% of the cases, it also appears after supratentorial craniotomy in 100% of cases. The accumulation of intracranial air can be acute (<72 hours) or delayed (≥72 hours). When intracranial air causes intracranial hypertension and has a mass-effect with neurological deterioration, it is called tension pneumocephalus. CASE DESCRIPTION: We represent a clinical case of a 75-year-old male patient with open penetrating head injury, complicated by tension pneumocephalus on the fifth day after trauma and underwent urgent surgical correction. Operation performed: Burr-hole placement in the right frontal region, evacuation of tension pneumocephalus. CONCLUSION: Tension pneumocephalus is a life-threatening neurosurgical emergency case, which needs to undergo immediate surgical or conservative treatment.