John Pollina

Cranial Birth Injuries in Term Newborn Infants

While cranial birth injuries in term infants are well recognized, to date, only small case series have been described. In an attempt to further define the spectrum of cranial birth injuries, we analyzed 41 consecutive cranial birth injuries at our institution over the period 1991–1998. The most common clinical presentations were apnea (39%) and seizures (37%). Average Apgar scores were 5.7 at 1 min and 7.3 at 5 min; 54% of infants had abnormally low Apgar scores at 1 min and 31% had abnormally low scores at 5 min. The most common intracranial lesion was subdural hemorrhage, present in 73% of infants; most had either a tentorial (57%) and/or interhemispheric (50%) location. Operative treatment was required in 5 infants (12%). Two of the 41 infants (4.8%) died. The study group was compared with a control group of 63 randomly selected births without cranial injury. Using a stepwise logistic regression model, independently significant variables included neonatal birth weight, Apgar scores at 1 and 5 min and mode of delivery. Compared with the controls, the study group had a significantly higher incidence of forceps and/or vacuum deliveries. Combining vacuum, forceps and urgent cesarean section deliveries together as ‘urgent’ and elective cesarean and spontaneous vaginal deliveries as ‘nonurgent’, we could find no significant differences between these two groups. Our data conflict with those of Towner et al. [N Engl J Med 1999;341:1709–1714], and suggest that the method of assisted delivery, rather than the urgency of the delivery or dysfunctional labor per se, is a more important variable in cranial birth injuries.

Intratumoral infusion of topotecan prolongs survival in the nude rat intracranial U87 human glioma model

Topotecan is a topoisomerase (topo) I inhibitor with promising activity in preclinical studies. We hypothesized that low-dose intratumoral delivery of topotecan would be highly effective for gliomas. Human glioma cell lines (U87, U138 and U373) displayed different sensitivities to topotecan (IC50 range: 0.037 μM to 0.280 μM) in cell culture. The most resistant of the glioma cell lines (U87) was implanted stereotactically into the brains of nude rats. Twelve days later, at which time tumor diameter measured 2 to 2.5 mm, animals were randomized to three groups: group I, intratumoral topotecan infused via osmotic pump (n = 12); group II, intratumoral saline infusion (n = 7); and group III, no treatment (n = 10). Animals were sacrificed when signs of deterioration developed, or at 60 days. Animals in group I had a mean survival time (MST) of > 55 days (range=40–60); whereas, those in groups II and III had MST of 26.1 (range=21–31) and 26.5 (range = 20–30) days, respectively. The differences in survival between group I and each of the other groups were statistically significant (p < 0.0001; Logrank Mantel-Cox). None of the animals that survived 60 days had histological evidence of residual tumor at sacrifice. Measurement of topotecan levels in normal brain revealed cytotoxic concentrations up to 4.5 mm from the site of infusion. This study demonstrates that intratumoral topotecan delivered via an osmotic pump prolongs survival in the U87 human glioma model.

Low-Pressure Shunt ‘Malfunction’ following Lumbar Puncture in Children with Shunted Obstructive Hydrocephalus

Most shunt malfunctions present with signs and symptoms of high intracranial pressure, and computed tomography scans demonstrate ventricular enlargement. However, several authors have described a rare ‘low-pressure’ hydrocephalic state in which ventricular enlargement can occur in the face of low, or even negative, intracranial pressures. We report 2 children with obstructive hydrocephalus in whom this ‘low-pressure state’ followed a lumbar puncture; in both children, the shunts were functioning properly despite increased ventricular size on computed tomography scans, and all symptoms resolved (and the ventricles returned to baseline) following a period of enforced recumbency without shunt revision. We hypothesize that subarachnoid cerebrospinal fluid leakage through the puncture site in the lumbar theca decreases the intracranial pressures globally to a point below the opening pressures of the shunt valves. The ventricular cerebrospinal fluid, unable to be drained through either the subarachnoid space or the shunt, accumulates within the ventricular system under low pressure. One consistent feature in our 2 patients has been the postural nature of the headaches. We recommend enforced recumbency and, if necessary, a blood patch to seal the lumbar leakage. Shunt revision or prolonged external ventricular drainage appears to be unnecessary in these patients. Finally, neurosurgeons should be aware of this potential complication.

The role of steroid administration in the management of dysphagia in anterior cervical procedures

Dysphagia is a common postoperative symptom for patients undergoing anterior cervical spine procedures. The purpose of this study is to present the current literature regarding the effect of steroid administration in dysphagia after anterior cervical spine procedures. We performed a literature search in the PubMed database, using the following terms: “dysphagia,” “ACDF,” “cervical,” “surgery,” “anterior,” “spine,” “steroids,” “treatment,” and “complications.” We included in our review any study correlating postoperative dysphagia and steroid administration in anterior cervical spine surgery. Studies, which did not evaluate, pre- and postoperatively, dysphagia with a specific clinical or laboratory methodology were excluded from our literature review. Five studies were included in our results. All were randomized, prospective studies, with one being double blinded. Steroid administration protocol was different in every study. In two studies, dexamethasone was used. Methylprednisolone was administrated in three studies. In four studies, steroids were applied intravenously, while in one study, locally in the retropharyngeal space. Short-term dysphagia and prevertebral soft tissue edema were diminished by steroid administration, according to the results of two studies. In one study, prevertebral soft tissue edema was not affected by the steroid usage. Furthermore, short-term osseous fusion rate was impaired by the steroid administration, according to the findings of one study. The usage of steroids in patients undergoing anterior cervical spine procedures remains controversial. Multicenter, large-scale, randomized, prospective studies applying the same protocol of steroid administration and universal outcome criteria should be performed for extracting statistically powerful and clinically meaningful results.

Posterior Reversible Encephalopathy Syndrome Resolving Within 48 Hours in a Normotensive Patient Who Underwent Thoracic Spine Surgery

Posterior reversible encephalopathy syndrome (PRES) usually manifests with severe headaches, seizures, and visual disturbances due to uncontrollable hypertension. A patient (age in the early 60s) with a history of renal cell cancer presented with lower-extremity weakness and paresthesias. Magnetic resonance imaging (MRI) of the thoracic spine revealed a T8 vertebral body metastatic lesion with cord compression at that level. The patient underwent preoperative embolization of the tumor followed by posterior resection and placement of percutaneous pedicle screws and rods. Postoperatively, the patient experienced decreased visual acuity bilaterally. Abnormal MRI findings consisted of T2 hyperintense lesions and fluid-attenuated inversion recovery changes in both occipital lobes, consistent with the unique brain imaging pattern associated with PRES. The patient’s blood pressure was normal and stable from the first day of hospitalization. The patient was kept on high-dose steroid therapy, which was started intraoperatively, and improved within 48 hours after symptom onset.

Bowel injury in lumbar spine surgery: a review of the literature

Although rarely documented in the medical literature, bowel perforation injury can be a severe complication of spine surgery. Our goal was to review current literature regarding this complication and study possible methods of avoidance. We conducted a literature search in the PubMed database between January 1960 and March 2016 using the terms abrasion, bowels, bowel, complication, injury, intestine, intra-abdominal sepsis/shock, perforation, lumbar, spine, surgery, visceral. Diagnostic criteria, outcomes, risk factors, surgical approach, and treatment strategy were the parameters extracted from the search results and used for review. Thirty-one patients with bowel injury were recognized in the literature. Bowel injury was more frequent in patients who underwent lumbar discectomy and microdiscectomy (18 of 31 patients, 58.1%). Minimally invasive surgery and lateral techniques involving fusions accounted for 10 of the reported cases (32.3%). Finally, 2 cases (6.5%) were reported in conjunction with sacrectomies and 1 case (3.2%) with posterior fusion plus anterior longitudinal ligament (ALL) release. Diagnosis was made mostly by clinical signs/symptoms of acute abdominal pain, post-surgical wound infection, and abscess or enterocutaneous fistulas. Significant risk factors for postoperative bowel injury were complex surgical anatomy, medical history of previous abdominal surgeries or infections, irradiation before surgery, errors related to surgical technique, lack of surgical experience, and instrumentation failure. The overall mortality rate from bowel injury was 12.9% (4 of 31 patients). The overall morbidity rate was 87.1% (27 of 31 patients). According to our review of the literature, bowel injury is linked to significant morbidity and mortality. It can be prevented with meticulous pre-surgical planning. When it occurs, timely treatment reduces the risks of morbidity and mortality.

Robotic Guidance for the Insertion of Posterior Pedicle Screws: 2-Dimensional Operative Video

Recent years have shown an increase in implementing robotics in surgical procedures. Utilizing robotic technology in spine surgery remains limited in comparison to other surgical fields. We present a surgical video of minimally invasive robotic-assisted insertion of posterior pedicle screws using the newest generation robotic technology (Mazor X, Mazor Robotics Ltd, Caesarea, Israel), in a 29-yr-old man who suffers from Grade I degenerative spondylolisthesis at L5-S1 levels and severe, right-sided foraminal stenosis. The plan was to perform anterior fusion at L5-S1 using robotic guidance with posterior pedicle screw supplementation due to his extensive smoking history. This technology has two distinct registration methods: (1) using a preoperative thin-cut computed tomography (CT) scan to create a surgical plan for screw placement; and (2) scan-and-plan using intraoperative 3-dimensional (3D) imaging to create a plan in real-time intraoperatively. We present the scan-and-plan technique. The widely used freehand technique allows the surgeon to manually direct tools and implants relying on the 6-degrees-of-freedom of the human arm. When Mazor X robotic technology is utilized, a pilot hole is drilled through a cannula docked to the bone above the entry point, which provides the surgeon with a planned trajectory and eliminates 4 of 6-degrees-of-freedom (up/down and yaw remain). This provides increased multidimensional control and reduces reliance on hand-eye coordination with simultaneous concentration on the imaging, potentially leading to increased rates of accuracy and reduction in severe complications of misplaced screws. Further prospective clinical studies are needed to determine the long-term effectiveness of this technology. Patient consent was obtained prior to performing the procedure. Institutional board review approval is not required for the report of a single case at the University at Buffalo.

Next-Generation Robotic Spine Surgery: First Report on Feasibility, Safety, and Learning Curve

BACKGROUND Pedicle screw placement is a commonly performed procedure. Robot-guided screw placement is a recent technological advance that has shown accuracy and reliability with first-generation platforms. OBJECTIVE To report our initial experience with the safety, feasibility, and learning curve associated with pedicle screw placement utilizing next-generation robotic guidance. METHODS A retrospective chart review was conducted to obtain data for 20 patients who underwent lumbar pedicle screw placement under robotic guidance after undergoing interbody fusion for lumbar spinal stabilization for degenerative disc disease with or without spondylolisthesis. The newest generation Mazor X (Mazor Robotics Ltd, Caesarea, Israel) was used. Accuracy of screw placement was determined to be grade I to IV. Grade I was in the pedicle (no breach/deviation), grade II was breach < 2 mm, grade III was breach 2 to 4 mm, and grade IV was breach >4 mm; breach direction (superior, lateral, inferior, or medial) was also recorded. RESULTS Twenty patients underwent robotically assisted pedicle screw placement of 75 screws at 24 levels. Seventy-four screw placements (98.7%) were grade I; 1 (1.3%) was grade II (medial). No complications occurred. Mean time for screw insertion was 3.6 min. Mean fluoroscopy time was 13.1 s and mean radiation dose was 29.9 mGy. CONCLUSION We found that next-generation robotic spine surgery was safe and feasible with reliable and precise accuracy and a minimal learning curve. As this technology improves, further novel applications are expected to develop. Further research is needed to determine long-term efficacy.

Cervical sagittal balance parameters after single-level anterior cervical discectomy and fusion: Correlations with clinical and functional outcomes

Background: Normal sagittal cervical alignment has been associated with improved outcome after anterior cervical discectomy and fusion (ACDF). Objective: The aim of this study is to identify alterations of cervical sagittal balance parameters after single-level ACDF and assess correlations with postoperative functionality. Methods: A retrospective chart review was performed between January 2010 and January 2014 to identify adult patients with no previous cervical spine surgery who underwent ACDF at any one level between C2 and C7 for the single-level degenerative disease. Tumor, infection, and trauma cases were excluded from the study. For the included cases, the following data were recorded preoperatively and 6 months–1 year after surgery: sagittal balance-marker measurements of the C1–C2 angle, C2–C7 angle, C7 slope, segmental angle at the operated level, and sagittal vertical axis (SVA) distance between C2 and C7, as well as the neck disability index and visual analog scale of pain. Results: The present study included 47 patients (average age: 51.2 years; range: 28–86 years). A moderate negative correlation between a smaller C2–C7 angle and the presence of right arm pain before treatment was found (P = 0.0281). Postoperatively, functionality scores significantly improved in all patients. C1–C2 angle increased with statistical significance (P = 0.0255). C2–C7 angle, segmental angle, C7 slope, and SVA C2–C7 distance did not change with statistical significance after surgery. C7 slope significantly correlated with overall cervical sagittal balance (P < 0.05). Conclusions: Single-level ACDF significantly increases upper cervical lordosis (C1–C2) without significantly changing lower cervical lordosis (C2–C7). The C7 slope is a significant marker of overall cervical sagittal alignment (P < 0.05).

Steinmann Pins for C1 Lateral Mass Screw Placement During Atlantoaxial Stabilization

OBJECTIVE The authors describe a modified technique for placement of the C1 lateral mass screw using a Steinmann pin as a guide. This technique minimizes dissection and provides atlantoaxial stabilization during arthrodesis. METHODS In our technique, a nonthreaded 1.6-mm spade-tip Steinmann pin is placed into the lateral mass of C1 to serve as a guide over which a powered drill is used for screw insertion. Perioperative data were collected for consecutive patients who underwent a C1-2 arthrodesis that involved the modified technique between March 2010 and July 2016. Data included blood loss, operative times, and C2 nerve root injury. RESULTS The data for 93 patients were reviewed. Most (91.4%) patients presented with a fracture from an acute trauma. A mean of 1.97 levels was fused in these patients, with a mean blood loss of 76 mL and a mean operative time of 144 minutes. The overall morbidity and mortality rate was 10.7%. The morbidity rate of 7.5% included 30-day postoperative complications of respiratory failure and dysphasia. There were no postoperative vertebral artery injuries, hardware failures, or instances of occipital neuralgia. CONCLUSIONS The use of Steinmann pins to guide the placement of C1 lateral mass screws is safe and effective in C1-2 arthrodesis. Limiting dissection minimizes blood loss and injury, maintains efficient operative time, and assists in accurate placement of the screws. Furthermore, with less manipulation and retraction of the C2 nerve root, postoperative occipital neuralgia and the need for C2 root transection are avoided.