Cardiopulmonary Dysfunction During Minimally Invasive Thoraco-Lumboendoscopic Spine Surgery

[Does experimental surgery still exist?]

During the last two decades research in surgery has changed from a specific to an interdisciplinary approach. Accordingly, the research approaches in surgery show marked overlap with those of other disciplines, such as oncology, immunology, gastroenterology, cardiology and intensive care medicine. This questions the need of experimental surgery in the future. A current survey, however, showed that experimental surgery still produces a multitude of excellent scientific studies, which substantially contribute to the development in surgery and, thus, to the improvement of surgical care. In addition experimental surgery coins the analytical thinking of young surgeons and mediates the enthusiasm and motivation to search for the undiscovered in surgery. Therefore, there is need to further support experimental surgery as an essential component of academic surgery. Thus, it can be concluded that experimental research still represents a prerequisite for innovations in operative medicine and also contributes to the improvement of scientific performance in surgery.

Preoperative predictors of prolonged postoperative mechanical ventilation in children following scoliosis repair

Scoliosis is associated with progressive restrictive lung disease and an increased risk of pulmonary complications following surgical correction. Identification of higher risks for prolonged postoperative mechanical ventilation (MV) improves postoperative care. Our objective was to determine if preoperative pulmonary function tests (PFT) predict prolonged postoperative MV (defined as MV >or=3 days). We correlated preoperative PFT (forced expired volume in 1 sec, FEV1; vital capacity, VC; inspiratory capacity, IC; maximal inspiratory pressure, MIP; total lung capacity, TLC; and residual volume, RV) and postoperative MV days in 125 patients who had scoliosis surgery (aged 13.7 +/- 3.0 (SD) years) from January 1990-July 2001. We had 71 male and 54 female patients. Scoliosis types were 13 congenital, 27 idiopathic, 57 neuromuscular, 23 syndrome/tumor, and 5 kyphoscoliosis. Forty patients (32%) had postoperative MV >or=3 days. Independent factors likely requiring postoperative MV >or=3 days were neuromuscular scoliosis (P < 0.001) and FEV1 <40% predicted. Independent factors most likely were: neuromuscular scoliosis with preoperative FEV1 <40% predicted (P < 0.01). Independent factors most unlikely were: idiopathic scoliosis (P < 0.002). VC <60% predicted, IC <30 ml/kg, TLC <60% predicted, and MIP <60 cm H2O correlated with postoperative MV >or=3 days (P < 0.05). We found no association between RV and postoperative MV. FEV1 <40% predicted, VC <60% predicted, IC <30 ml/kg, TLC <60% predicted, MIP <60 cm H2O, and neuromuscular disease each correlated with prolonged postoperative MV. Neuromuscular disease or a preoperative FEV(1) <40% predicted were more likely, and older children with neuromuscular disease and FEV1 <40% predicted were most likely to require prolonged postoperative MV (P < 0.01). Clearly FEV1, and possibly VC, IC, TLC, and MIP, may increase accuracy in predicting the need for prolonged postoperative MV.

The effect of scoliosis surgery on lung function in the immediate postoperative period

STUDY DESIGN

Prospective, single-cohort study.

OBJECTIVES

To determine the immediate change in pulmonary function test (PFT) in children following scoliosis surgery.

SUMMARY OF BACKGROUND DATA

The number of pediatric scoliosis surgeries is increasing each year because of recent advances in spinal instrumentation, surgical techniques, and improved perioperative monitoring. Pulmonary function decreases immediately following scoliosis surgery, but the extent of this decrease is not well documented in pediatric patients. To use preoperative PFTs to assess the risk of postoperative complications, knowledge of the postoperative decline in PFT is necessary.

METHODS

We measured preoperative and daily postoperative PFT in 24 children who had scoliosis surgery (age 12.7 +/- 2.7 [SD] years) from January 2002 to June 2003. There were 10 male and 14 female patients. Two (8%) patients had congenital scoliosis, 11 (46%) had idiopathic scoliosis, 9 (38%) had scoliosis due to a neuromuscular disease, and 2 (8%) had kyphoscoliosis. Fifteen (62%) patients had posterior spinal fusion (PSF), 5 (21%) had anterior spinal fusion (ASF), and 4 (17%) had both ASF and PSF performed. PFT parameters (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], FEV1/FVC, and forced expiratory rate between 25% and 75% of FVC [FEF25%-75%]) were measured before surgery and daily after surgery by bedside spirometry until hospital discharge.

RESULTS

PFT declined up to 60% after surgery. The PFT nadir is at 3 days. PFT values remained significantly decreased at 1 week, with values at about half of preoperative baseline. No patient required postoperative mechanical ventilation > or =3 days. There was no statistical significance between the degree of decline in PFT with etiology of either the scoliosis or the type of surgery performed.

CONCLUSIONS

Our study found that patients are still at risk for postoperative complications as long as 1 week postoperatively and that PFTs do not return to near baseline until 1 to 2 months after surgery. The postoperative decrease in PFT should be considered during preoperative prediction of postoperative risk.

Endoscopic lateral transpsoas approach to the lumbar spine

STUDY DESIGN

A description of a novel surgical approach to the lumbar spine and a prospective evaluation of the early surgical outcomes.

OBJECTIVES

Describe the early postoperative results and the operative technique of a new, minimally invasive transpsoas approach for anterior fusion of the lumbar spine that minimizes the risk to large vessels and other critical structures.

SUMMARY OF BACKGROUND DATA

Standard anterior endoscopic approaches to the lumbar spine require mobilization of the great vessels and sympathetic plexus. Vascular injury and retrograde ejaculation are complications clearly associated with this approach. A retroperitoneal, transpsoas approach to the lumbar spine may reduce these risks.

METHODS

From 1996 to 2002, 21 patients (13 females, 8 males; mean age 50.0 years) underwent an endoscopic, retroperitoneal transpsoas approach for exposure of the lumbar spine. Surgical indications included discogenic pain in 14 patients, spinal instability at a level adjacent to a previous fusion in 3 patients, and progressive degenerative scoliosis in 4 patients. Data were reviewed to document the early postoperative results for this procedure. Illustrations were created to clearly describe this approach.

RESULTS

Average operative time for the single level cases was 149 minutes (range 120-170 minutes); blood loss was 150 cc (range 50-650); postoperative hospital stay was 4.1 days. At long-term follow-up, visual analogue scale scores had decreased an average of 5.9. Mean follow-up was 3.1 years (range 2 months-6.0 years). Six patients (30%) experienced paresthesias in the groin/thigh region. Five of these same patients also complained of groin/thigh pain (27%). Two patients had symptoms that lasted longer than 1 month. One patient was converted to a mini-open lateral approach. There were no vascular injuries.

CONCLUSIONS

Early results show the endoscopic lateral transpsoas approach to the lumbar spine to be a safe, minimally invasive method for anterior fusion of the first through the fourth lumbar vertebrae. Although there is a risk of groin/thigh numbness or pain, and these symptoms are mostly transient. This approach allows for exposure of the lumbar spine without mobilization of the great vessels or sympathetic plexus.