Results of posterior spinal fusion after failed anterior vertebral body tethering

PURPOSE

In patients with adolescent idiopathic scoliosis (AIS) undergoing anterior vertebral tethering (AVBT), some will subsequently require posterior spinal fusion (PSF). Limited data exist on clinical and radiographic outcomes of fusion after tether failure.

METHODS

490 patients who underwent AVBT were retrospectively analyzed. Twenty patients (4.1%) subsequently underwent conversion to PSF. A control group of patients with primary PSF (no previous AVBT) was matched for comparison. Data were compared using paired t-tests and Fisher Exact Tests.

RESULTS

There was a significant increase in estimated blood loss (EBL) (p = 0.002), percent estimated blood volume (%EBV) (p = 0.013), operative time (p = 0.002), and increased amount of fluoroscopy (mGy) (p = 0.04) as well as number of levels fused (p = 0.02) in the AVBT conversion group compared to primary fusion. However, no difference was found in implant density (p = 0.37), blood transfusions (p = 0.11), or intraoperative neuromonitoring events (p > 0.99). Both groups attained similar thoracic and lumbar percent correction (major coronal curve angle) from pre-op to the latest follow-up (thoracic p = 0.507, lumbar p = 0.952).

CONCLUSION

A subset of patients with AVBT will require conversion to PSF. Although technically more challenging, revision surgery can be safely performed with similar clinical and radiographic outcomes to primary PSF.

LEVEL OF EVIDENCE: 3

Do Prophylactic Inferior Vena Cava Filters Affect the Rates of Venous Thromboembolism and Pulmonary Embolism in Patients Undergoing Major Spine Surgery?

STUDY DESIGN

Retrospective Analysis.

BACKGROUND

Venous thromboembolism (VTE) represents a significant cause of morbidity and mortality in major spine surgery. Placement of prophylactic inferior vena cava filters (IVCF) in patients undergoing major spine surgery was previously adopted at our institution. This study reports our experience and compares VTE rates between patients with and without preoperative IVCF placement.

METHODS

A Retrospective comparative study was conducted on adult patients who underwent IVCF placement and those who did not prior to their spinal fusion procedure, between 2013 and 2016. Thoracolumbar fusions (anterior and/or posterior) of 7 or more levels, spinal osteotomies, and a minimum of a 3-month follow-up were included. Traumatic, oncologic, and cervical pathology were excluded. Primary outcomes measured included the incidence of overall VTE (DVT/PE), death, IVCF related complications, and IVCF retrieval.

RESULTS

386 patients who underwent major spine surgery, 258 met the eligibility criteria. Of those patients, 105 patients (40.7%) had prophylactic IVCF placement. All patients had postoperative SCDs and chemoprophylaxis. The presence of an IVCF was associated with an increased rate of overall VTE (14.3% vs 6.5%, P ≤ .05) and DVT episodes (8.6% vs 2.6%, P = .04). The rate of PE for the IVCF group and non-IVCF group was 8.6% and 4.6%, respectively, which was not statistically significant (P = .32). The all-cause mortality rate overall of 2.3% was statistically similar between both groups (P = 1.0). The IVCF group had higher rates of hematoma/seroma vs the non-IVCF group (12.4% vs 3.9%, P ≤ .05). 99 IVCFs were retrievable designs, and 85% were successfully retrieved. Overall IVCF-related complication rate was 11%.

CONCLUSIONS

No statistical difference in PE or mortality rates existed between the IVCF and the control group. Patients with IVCF placement experienced approximately twice the rate of VTE and three times the rate of DVT compared to those without IVCF. The IVCF-related complication rate was 11%. Based on the results of this study, the authors recommend against the routine use of prophylactic IVCFs in adults undergoing major spine surgery.

LEVEL OF EVIDENCE

III.

Management of intraoperative hemorrhage during NOTES: a prospective, randomized comparison

BACKGROUND

The optimal strategy to manage intraoperative hemorrhage during NOTES is unknown. A randomized comparison of three instruments for hemorrhage control was performed [prototype endoscopic bipolar hemostasis forceps (BELA) vs. prototype endoscopic clip (E-CLIP) applier versus laparoscopic clip (L-CLIP) applier].

METHODS

A hybrid transvaginal NOTES model in swine was used, with hemorrhage induced in either the gastroepiploic (GE) arteriovenous bundle (vessel diameter ~3 mm) or in distal mesenteric vessels (vessel diameter ~1-2 mm). Hemostasis was attempted three times per vessel using each instrument in a randomized order. Full laparoscopic salvage was performed if hemorrhage persisted beyond 10 min. Outcomes included primary success rate (PS), primary hemostasis time (PHT), number of device applications (DA), and overall hemostasis time (OHT, including salvage).

RESULTS

Seventy hemostasis attempts were made in 12 swine. PS was 42-67 % for the GE vessels, with no difference between instruments. PHT and OHT also were similar between instruments, with the BELA and L-CLIP having a higher number of DA. PS was (80-100 %) in mesenteric vessels, with the BELA and L-CLIP resulting in a shorter mean PHT compared with the E-CLIP.

CONCLUSIONS

All three instruments had similar effectiveness in achieving primary hemostasis during hybrid NOTES. Management of small vessel bleeding (1-2 mm) in a porcine model is effective using all three instruments but may be most efficient with the BELA or L-CLIP. Large vessel bleeding (≥3 mm) may be best managed by adding laparoscopic ports for assistance while maintaining a low threshold for conversion to full laparoscopy.