Incidence, clinical features, and risk factors for acute pancreatitis following posterior instrumented fusion surgery for lumbar degenerative disease: a single-center, retrospective analysis of 20,929 patients

PURPOSE

The aim of this study is to identify the incidence, clinical features, and risk factors for postoperative acute pancreatitis (PAP) after lumbar surgery.

METHODS

We retrospectively analyzed patients who developed PAP after posterior lumbar fusion surgery. For each PAP patient, data were collected for four controls who underwent procedures in the same period and did not develop PAP. Statistical methods included univariate and multivariate analyses.

RESULTS

Totally, 21 out of 20,929 patients were diagnosed with PAP (0.10%) after posterior lumbar fusion surgery. Patients with degenerative lumbar scoliosis were at higher risk of developing PAP (P < 0.05). With atypical clinical features, PAP occurred within 3 days (0-5) after surgery. PAP patients had significantly higher incidence of osteoporosis (47.6 vs. 22.6%, P = 0.030) and fusion of L1/2(42.9 vs. 4.3%, P = 0.010), lower albumin (42.2 ± 4.1 vs. 44.3 ± 3.2 g/L, P = 0.010), more fusion segments (median 4 vs. 3, P = 0.022), larger surgical invasiveness index (median 9 vs. 8, P = 0.007), longer operation duration (232 ± 109 vs. 185 ± 90 min, P = 0.041), greater estimated blood loss (median 600 vs. 400 mL, P = 0.025), lower intraoperative mean arterial pressure (87.2 ± 9.9 vs. 92.1 ± 8.8 mmHg, P = 0.024). Multivariate logistic regression analysis found three independent risk factors: fusion of L1/2, surgical invasiveness index > 8, and intraoperative mean arterial pressure < 90 mmHg. All patients were treated with conservative therapy and fully recovered after 8.1 (4-22) days.

CONCLUSION

The incidence of PAP following posterior surgery for degenerative lumbar disease was 0.10%, and its clinical features were not typical. The fusion of L1/2, high surgical invasiveness index, and low intraoperative mean arterial pressure were independent risk factors for PAP after surgery for lumbar degenerative disease.

Cross-sectional analysis of risk factors for surgical site infection secondary to spinal internal fixation via the posterior approach

Objective

This study was performed to investigate the risk factors related to surgical site infection (SSI) secondary to spinal internal fixation via the posterior approach.

Methods

Patients who had undergone spinal internal fixation via the posterior approach were selected for inclusion in this cross-sectional study. Factors related to SSI were analysed using univariate and multivariate analyses.

Results

Among 4,350 patients, 66 had SSI (infection prevalence of 1.5%). Multivariate logistic regression analysis demonstrated that age of >60 years, surgical duration of >3 hours, haemoglobin concentration of <80 g/L, serum albumin concentration of <30 g/L, diabetes history, and blood loss of >1,000 mL were significantly correlated with SSI secondary to spinal internal fixation via the posterior approach.

Conclusions

This study provides information on SSI secondary to spinal internal fixation via the posterior approach. We found that age of >60 years, surgical duration of >3 hours, haemoglobin concentration of <80 g/L, serum albumin concentration of <30 g/L, diabetes history, and blood loss of >1,000 mL are directly correlated with SSI secondary to spinal internal fixation via the posterior approach.

Predictors of postoperative urinary retention after posterior spinal fusion for adolescent idiopathic scoliosis

PURPOSE

To determine predictors for postoperative urinary retention in adolescents undergoing posterior spinal fusion for idiopathic scoliosis. Postoperative urinary retention affects almost every third adolescent after spinal fusion for idiopathic scoliosis. There are limited data regarding the risk factors of postoperative urinary retention in this patient group.

METHODS

A retrospective study with prospectively collected urinary retention data from paediatric spine register with 159 consecutive patients (114 females, mean age 15.6 years, range 10-21 years) undergoing pedicle screw instrumentation for adolescent idiopathic scoliosis at a university hospital between May 2010 and April 2020. Postoperative urinary retention was defined as an inability to void after catheter removal and documented residual over 300 mL as confirmed using an ultrasound or by catheterization.

RESULTS

Postoperative urinary retention was diagnosed in 33% (53 of 159) of the patients during hospital stay. Opioid amount on the day of catheter removal (OR 6.74 [95% CI: 2.47, 18.36], p < 0.001), male gender (OR 2.26 [95% CI: 1.01, 5.05], p = 0.048), and increasing weight (OR 1.04 [95% CI: 1.01, 1.07], p = 0.014) were associated with postoperative urinary retention. Mean opioid consumption on the day of catheter removal was 0.81 mg/kg (95% CI: 0.66, 0.96) in the retention group vs 0.57 mg/kg (95% CI: 0.51, 0.64) in the non-retention group, p < 0.001.

CONCLUSIONS

Higher total opioid consumption, opioid amount on the day of catheter removal, higher weight, and male gender increases the risk of postoperative urinary retention in adolescents with idiopathic scoliosis undergoing posterior spinal fusion.

Risk factors of meralgia paresthetica after prone position surgery: Possible influence of operating position, laminectomy level, and preoperative thoracic kyphosis

Obesity and a prolonged surgical duration are reported risk factors for meralgia paresthetica (MP) after prone position surgery; however, this fails to explain why MP seldom occurs after prone position craniotomy. We reviewed the incidence of MP after spinal surgery and craniotomy in the prone position and investigated whether unidentified factors are involved in the mechanism of postoperative MP. Between January 2014 and March 2020, we performed 556 prone position surgeries. We excluded patients aged ≤16 years and those who were comatose or who required redo-surgery, and reviewed 446 eligible patients (124 who underwent craniotomies and 322 who underwent posterior spinal surgeries). Postoperative MP occurred in 46 (10.3%) patients with a higher incidence after spinal surgery than after craniotomy (13.7% vs. 1.6%, p < 0.001). Among the 322 patients who received posterior spinal surgery, thoracic and lumbar laminectomies were associated with a higher incidence of MP than cervical laminectomy. Analyses limited to those patients who received thoracic and lumbar laminectomies revealed that the preoperative thoracic kyphosis (TK) angle was significantly greater in patients with MP than in those without MP (average TK angle, 38.9° vs. 23.1°; p < 0.001), and that the preoperative lumbar lordosis angle did not significantly differ between the two groups. Apart from the known predisposing factors, we found that thoracolumbar-sacral laminectomy in patients with a greater TK angle is also a risk factor for MP after prone position surgery.

Esophageal perforation caused by a thoracic pedicle screw

This grand round raises the risk of a rare complication that can be avoided with the knowledge of the particular anatomy of scoliosis vertebra. Transpedicular screws have been reported to enhance the operative correction in scoliosis surgery. The narrow and inconsistent shape of the thoracic pedicles makes the placement of pedicle screws technically challenging. Furthermore, in thoracic curves, the close proximity of the spinal cord and major soft tissue structures also adds a greater risk to the procedure. The esophagus lies close to the upper thoracic vertebras and, an anterior cortical perforation can cause esophageal injury. We report a case of anterior cortical perforation by a T4 pedicle screw complicated by an esophageal perforation in a 15-year-old girl with convulsive encephalopathy. She was operated for a severe neurological scoliosis (Rett syndrome). Her neurological condition deteriorated 3 years after the posterior spinal surgery, requiring a percutaneous gastrostomy. An intra-esophageal screw was discovered incidentally during an endoscopy. We decided not to remove this screw, because the patient's health status presented a surgical contraindication. The patient showed no apparent discomfort at the 10-year follow-up examination after spinal arthrodesis. Esophageal perforation caused by a posterior pedicle screw is very rare. We highlight the risk of injury to esophagus from pedicle screws in upper thoracic vertebra. The systematic removal of a malpositioned screw must be discussed, on a case-to-case benefit-risk basis, especially if the patient has numerous comorbidities, given the long-term tolerance of a number of these improperly positioned implants.

Tension Pneumothorax as a Complication of Inadvertent Pleural Tears During Posterior Spinal Surgery

OBJECTIVE

To review and expose the occurrences of tension pneumothorax as a result of pleural tear during posterior spinal surgery.

METHODS

Intraoperative reports were retrospectively reviewed for 2 patients who underwent posterior spinal fusion and experienced pleural tear and subsequent tension pneumothorax. Surgical decisions for recognition and treatment were also reviewed.

RESULTS

Unrecognized pleural tearing led to the formation of tension pneumothorax in both patients studied. Onset of respiratory signs and symptoms were delayed, occurring in the recovery room for the first patient and intraoperatively for the second. Both patients were successfully treated with conversion to open pneumothorax and placement of chest tubes.

CONCLUSIONS

Tension pneumothorax is a complication that can arise during posterior thoracic spinal surgery as a result of an inadvertent pleural tear. Awareness of this potentially fatal complication will greatly help in the timely recognition and treatment of this condition if this situation occurs. The authors recommend a low threshold for chest tube placement in patients with known or suspected pleural tears or in patients with undiagnosed respiratory failure undergoing posterior thoracic spine surgery.

Prone position-related meralgia paresthetica after lumbar spinal surgery : a case report and review of the literature

Lateral femoral cutaneous neuropathy occurring during spinal surgery is frequently related to iliac bone graft harvesting, but meralgia paresthetica (MP) can result from the patient being in the prone position. Prone position-related MP is not an uncommon complication after posterior spine surgery but there are only few reports in the literature on this subject. It is usually overlooked because of its mild symptoms and self-limiting course, or patients and physicians may misunderstand the persistence of lower extremity symptoms in the early postoperative period to be a reflection of poor surgical outcome. The authors report a case of prone position-related MP after posterior lumbar interbody fusion at the L3-4 and reviewed the literature with discussion on the incidence, pathogenesis, and possible risk factors related to this entity.