Posterior-only Resection of Single Hemivertebrae With 2-Level Versus >2-Level Fusion: Can We Improve Outcomes?

BACKGROUND

The outcomes of congenital scoliosis (CS) patients undergoing hemivertebra (HV) resection surgery with a 2-level fusion versus a >2-level fusion are unclear. We hypothesized that CS patients undergoing HV resection and a >2-level fusion have decreased curve progression and reoperation rates compared with 2-level fusions.

METHODS

Retrospective review of prospectively collected data from a multicenter scoliosis database. Fifty-three CS patients (average age 4.5, range 1.2 to 10.9 y) at index surgery were included. Radiographic and surgical parameters, complications, as well as revision surgery rates were tracked at a minimum of 2-year follow-up.

RESULTS

Twenty-six patients had a 2-level fusion while 27 patients had a >2-level fusion with similar age and body mass index between groups. The HV was located in the lumbar spine for 69% (18/26) 2-level fusions and 30% (8/27) >2-level fusions ( P =0.006). Segmental HV scoliosis curve was smaller in 2-level fusions compared to >2-level fusions preoperatively (38 vs. 50 degrees, P =0.016) and at follow-up (25 vs. 34 degrees, P =0.038). Preoperative T2-T12 (28 vs. 41 degrees, P =0.013) and segmental kyphosis (11 vs. 23 degrees, P =0.046) were smaller in 2-level fusions, but did not differ significantly at postoperative follow-up (32 vs. 39 degrees, P =0.22; 13 vs. 11 degrees, P =0.64, respectively). Furthermore, the 2 groups did not significantly differ in terms of surgical complications (27% vs. 22%, P =0.69; 2-level fusion vs. >2-level fusion, respectively), unplanned revision surgery rate (23% vs. 22%, 0.94), growing rod placement or extension of spinal fusion (15% vs. 15%, P =0.95), or health-related quality of life per the EOS-Questionnaire 24 (EOSQ-24). Comparison of patients with or without the need for growing rod placement or posterior spinal fusion revealed no significant differences in all parameters analyzed.

CONCLUSIONS

Two-level and >2-level fusions can control congenital curves successfully. No differences existed in curve correction, proximal junctional kyphosis or complications between short and long-level fusion after HV resection. Both short and long level fusions are viable options and generate similar risk of revision. The decision should be individualized by patient and surgeon.

The Effect of Routine Reversal of Neuromuscular Blockade on Adequacy of Recurrent Laryngeal Nerve Stimulation during Thyroid Surgery

Testing of the integrity of the recurrent laryngeal nerve during thyroid surgery has become routine practice for many surgeons to aid dissection and minimise the chance of inadvertent nerve injury. We hypothesised that routine reversal of an intermediate-acting, non-depolarising neuromuscular blocking agent would improve conditions for stimulation of the recurrent laryngeal nerve. We conducted a single-centre, randomised, double-blind placebo-controlled trial of patients undergoing thyroid surgery by the same surgeon. After randomisation, the participants received either neostigmine 2.5 mg with glycopyrrolate 0.4 mg or placebo, at 30 minutes after induction of anaesthesia and administration of 0.4 mg/kg of atracurium. The primary outcome was the subjective assessment by the surgeon as to whether the neuromuscular function was adequate for stimulation of the recurrent laryngeal nerve using a neuromuscular integrity monitor (NIM). Time to NIM stimulation was 44.6 minutes in the placebo group and 41.4 minutes in the intervention group ( P=0.268). Of the 21 patients who received the neuromuscular blockade reversal, 20 (95.2%) had adequate surgical conditions for NIM stimulation, compared to 9 out of 18 patients (50%) in the placebo group ( P=0.002). Three of the ten patients (30%) with inadequate reversal showed no evidence of residual blockade assessed peripherally. The routine reversal of neuromuscular blockade at 30 minutes post induction appears to result in adequate surgical conditions for safe stimulation of the recurrent laryngeal nerve. Return of neuromuscular function at a peripheral site does not guarantee adequate laryngeal muscle function for use of the NIM.

In vivo target promoter-binding activities of a xenobiotic stress-activated TGA factor

Xenobiotic chemicals induce the expression of nuclear detoxification genes. A full understanding of this protective response will require characterization of its transcriptional regulatory machinery. We describe here the use of a recently developed plant chromatin immunoprecipitation (ChIP) assay to define nuclear promoter targets of TGA1a, a tobacco basic/leucine zipper transcription factor whose activity is potentiated by herbicide-induced xenobiotic stress. TGA1a selectively binds as-1-type cis-elements, which regulate transcription of putative detoxification and defense genes. With ChIP, we show that endogenous TGA1a binds as-1-containing promoter sequences of two tobacco glutathione S-transferase genes, GNT1 and GNT35. This binding activity is strongly enhanced by xenobiotic stress, as is expression of these genes. In contrast, TGA1a apparently does not bind in vivo to functional as-1 elements in promoters of PR-1a and PG13, genes whose expression is insensitive to this stimulus. The findings here thus discriminate between a number of possible functional promoter binding sites for a trans-regulatory factor, within the context of a signal response pathway.