Comparison of thoracoscopic and open thoracic discectomy in a live ovine model for anterior spinal fusion

STUDY DESIGN

The authors undertook a randomized comparison of 30 thoracoscopic and 30 open thoracic discectomies for anterior spinal fusion in a live sheep model.

OBJECTIVES

To compare in a live sheep model discectomies performed using a thoracoscopic technique with those using an open thoracotomy technique to validate the efficacy of thoracoscopic disc and end plate removal for potential fusion.

SUMMARY OF BACKGROUND DATA

In 1993, Mack and Regan described a technique for video-assisted thoracic surgery that resulted in less morbidity than open techniques. Subsequent reports support the finding that thoracoscopic spinal surgery results in less morbidity.

METHODS

Sixty discectomies were performed in 10 live sheep. In each sheep, three randomly selected discectomies were performed thoracoscopically, and, subsequently, three open discectomies were performed. The animal then was killed, and the spine was sectioned and analyzed by computer imaging.

RESULTS

Statistical analysis found no significant difference in the amount of disc resected (t' = 1.9639, t0.025, 60 = 2.000, alpha = 0.05). The mean percentage of disc resected was 67.8% (range, 0-92.2%) in the thoracoscopic group and 76.1% (range, 44.9-95.4%) in the open group. More than 50% of the disc was excised in 27 of 30 spines (90%) in the thoracoscopic group and in 29 of 30 (96.7%) in the open group. This difference was not statistically significant (theta 2(0.05, 1) = 3.84, theta 2' = 1.07).

CONCLUSION

The findings in this study indicate that the thoracoscopic discectomy technique is equivalent to the open technique in the amount of disc and end plate resected. In addition, these findings suggest that thoracoscopic discectomies provide adequate disc resection to provide for an acceptable fusion rate according to the criteria demonstrated by Bunnell in 1982 and therefore support the efficacy of a thoracoscopic technique for anterior spinal fusion.

Placement of a bladder neck purse-string cuff for the management of incontinence in children with myelodysplasia

OBJECTIVES

Numerous surgical procedures have been developed in an attempt to increase bladder compliance and/or outlet resistance for the treatment of intractable incontinence in children with neurogenic lower urinary tract dysfunction. We report our experience with the development of a biocompatable purse-string cuff to increase outlet resistance by providing circumferential compression at the bladder neck.

METHODS

A total of 12 children (6 boys, 6 girls) with myelodysplasia and persistent incontinence despite clean intermittent catheterization (CIC) and pharmacotherapy underwent urodynamic testing and cystoscopy that revealed neurogenic bladders with concomitant intrinsic sphincter deficiency. Through an anterior approach, the bladder neck was mobilized and wrapped with 5-mm polytetrafluoroethylene tubing. Five-millimeter woven polyester tape was then placed circumferentially within the polytetrafluoroethylene tubing lumen, purse-stringed under tension with a silicone tubing shod to appose the mucosa of the bladder neck, and secured under such tension with a surgical clip. Ten of the 12 patients underwent concomitant augmentation cystoplasty.

RESULTS

Nine of 12 children (age range at time of operation 2.5 to 16 years) are continent on CIC in follow-up ranging from 6 months to 12 years. Four cuffs had to be surgically removed postoperatively. Two were removed secondary to inadvertent transvaginal placement. Two other cuffs were removed for infection. One child with persistent postoperative incontinence had the cuff retightened through a minor surgical procedure and has remained dry. Annual renal ultrasound examinations reveal stabilization of upper urinary tracts throughout the follow-up period in all but 1 patient. Postoperative urodynamic studies reveal increased bladder capacity, decreased intravesical pressures, and increased leak point pressures.

CONCLUSIONS

The purse-string bladder neck cuff in combination with augmentation cystoplasty, when warranted, provides excellent, durable continence rates in children with myelodysplasia and neurogenic bladders. Attributes of the cuff are its relative low cost, ease of construction, unchanged angle of the bladder neck making catheterization easy, and potential adjustability in patients with persistent incontinence.

Prevalence of perioperative complications after anterior spinal fusion for patients with idiopathic scoliosis

Anterior spinal fusion (ASF) has been proven to improve curve correction, save motion segments, and decrease the rate of pseudarthrosis when compared with posterior spinal fusion alone. However, in patients with idiopathic scoliosis, the complication rate of the anterior approach to the spine using current techniques has only been scantly defined in the literature. This is a retrospective review of consecutive patients who underwent primary ASF for idiopathic scoliosis to determine the prevalence and types of complications specifically related to the anterior approach. All patients who underwent primary ASFs for idiopathic scoliosis done by one of two orthopaedic surgeons between October 1986 and July 1992 were reviewed. Adequate records were available for 98 of 103 patients. The average age at time of surgery was 22 years (range, 10-60 years). Complications were divided into three groups: major (resulting in permanent sequelae or necessitating a second major operation); minor (resulting in a prolonged hospital stay, necessitating a minor operation, and/or resulting in a significant temporary hardship or persistent minor problem); and insignificant (anything less than minor). One of 98 patients had a major complication (a pelvic deep venous thrombosis that required operative thrombectomy). Twenty-five of 98 patients had 28 complications classified as minor, and 28 of 98 patients had 30 complications classified as insignificant. Smoking was a significant risk factor for the development of minor complications. There was no statistically significant relationship between the development of complications and the degree of curve, the approach used, the procedure performed, or the performance of rib resections. The anterior approach to the spine in patients with idiopathic scoliosis in this series was very safe, with only one major complication in 98 patients. However, minor and insignificant complications were quite common, occurring in 45 of 98 patients (46%). Smoking was a significant risk factor for minor complications.

Diagnostic dilemma: left aortic arch with right descending aorta--a rare vascular ring

An infant had a rare type of vascular ring comprising a left aortic arch, a retroesophageal transverse aorta, a right descending aorta, and a right ligamentum arteriosum. Noninvasive studies including echocardiography with Doppler color flow mapping and magnetic resonance imaging were diagnostic of a vascular ring. However, only angiography prospectively established the exact type of ring. This report discusses the pitfalls of noninvasive studies used to diagnose unusual arch anomalies.

Innominate artery compression of the trachea: diagnosis and treatment by anterior suspension. A 25-year experience

Suspension of the innominate artery to the sternum has been a widely accepted therapy for the relief of tracheal compression. Recently, reimplantation of the innominate artery has been advocated as a superior operative procedure. While generally successful, arterial transfer carries the risk of early bleeding and stroke, and the potential for late stenosis at the anastomotic site. Between 1969 and 1994, 25 infants and children at our institution received diagnoses of innominate artery compression and were treated by anterior suspension. All presented with stridor and one third had a history of suspected or proven apnea. Twenty-four children had excellent results, while 1 required resuspension after stridor returned. There were no major complications. Our series strongly supports the belief that anterior suspension of the innominate artery is a successful and reliable operation with minimal morbidity and mortality. More complex procedures are rarely indicated.

The safety of continuous pleural lignocaine after thoracotomy in children and adolescents

Several studies have proven pleural bupivacaine effectively provides postthoracotomy analgesia for both children and adults. When 0.25% bupivacaine is administered as a continuous infusion or repeated bolus, serum bupivacaine levels frequently approach the toxic range. The hazards of bupivacaine toxicity are more difficult to monitor, especially in children who may not report symptoms of local anaesthetic toxicity. Because of this concern, we initiated the use of pleural lignocaine to provide postthoracotomy analgesia for paediatric patients. The records of all patients receiving pleural lignocaine from January 1991 to December 1992 were reviewed. A total of 98 pleural catheters were inserted in 96 patients ranging in age from five months to 20 years. Seven patients had lignocaine levels that exceeded 5 micrograms.ml-1 and no patient manifested symptoms of systemic toxicity. This study shows that the administration of pleural lignocaine is a safe method of providing postthoracotomy analgesia. Lignocaine infusions in the dosage range of 20 to 40 micrograms.kg-1.min-1 rarely produce toxic levels, and monitoring of lignocaine levels every 12 h is an effective method of screening for toxicity.

Coarctation of the aorta: diagnostic imaging after corrective surgery

The clinical evaluation and management of the patient with coarctation of the aorta continues to evolve. Traditional imaging evaluation by plain film chest radiography, barium esophagography, and arteriography with pressure measurements across the coarctation has been largely supplanted by Doppler echocardiography and magnetic resonance imaging (MRI). The complications of surgery and balloon angioplasty, including residual or recurrent coarctation and aneurysm, can also be evaluated noninvasively by echocardiography and MRI. Chest radiography continues to play an important role in "first discovery" imaging in asymptomatic patients.

Pacemaker contact sensitivity: clinical recognition and management

We report a patient in whom vesicular lesions of the skin developed overlying the pacemaker at intervals of 3 to 8 months after each of three consecutive insertions. Patch skin tests were positive for titanium and polyurethane sensitization. Although pacemaker contact sensitivity is rare, its recognition is of vital importance to the pacemaker-dependent patient.

Staged repair of pentalogy of Cantrell with tetralogy of Fallot

We report a successful two-stage repair of tetralogy of Fallot associated with pentalogy of Cantrell. The first stage, performed in the neonatal period, consisted of repairing the omphalocele, separating the peritoneal from the pericardial cavities, and covering the heart. The second stage, performed at 6 years of age, consisted of complete intracardiac repair and placing the heart in the chest. The patient is alive and well 18 months after the operation.

Pressure-volume relationship of the fetal lamb heart

In contrast to the adult heart, the fetal heart reportedly has little functional reserve. With increased clinical emphasis on fetal cardiac diagnosis, neonatal surgery, and the potential for future fetal cardiac intervention, it is essential that we better understand fetal cardiac function. Therefore, to demonstrate the extent of fetal cardiac preload reserve, we studied 10 fetal lambs using an isolated, isovolumic, blood-perfused heart preparation. We maintained constant afterload, inotropic state, coronary blood flow, heart rate, and perfusate blood gas values. As left ventricular (LV) volume (preload) was incrementally increased, LV end-diastolic pressure and LV peak systolic pressure were recorded. Linear regression analysis demonstrated that increases in LV developed pressures were predicted by the LV volume, demonstrating the presence of the Frank-Starling mechanism in each case. The plateau of the Starling pressure-volume curve occurred at an LV end-diastolic pressure of 12.5 +/- 4.79 mm Hg (95% confidence interval, 9.07 to 15.9 mm Hg), lower than the plateau expected in the adult heart. This implies that, in the management of fetal and immature neonatal hearts, preload reserve plays an important but limited role in cardiac reserve.

Thymolipoma: computed tomographic appearances

The computed tomographic (CT) appearances of a thymolipoma are described in a 5 1/2-year-old girl. The location and CT appearances of the tumor appear to be specific for the diagnosis of thymolipoma.

De novo circumscribed pulmonary lobar cystic lymphatic anomaly in a young boy. A possible sequela of bronchopulmonary dysplasia

This report describes a massive pulmonary lymphatic cystic anomaly affecting the right lower lobe of a nine-year-old boy. A year earlier, only an ill-defined small infiltrate could be seen in the affected lobe radiologically. The pathogenesis of this highly unusual lesion is discussed, taking into consideration the possible role of three months of mechanical ventilation in the neonatal period.

Pediatric heart transplantation at St. Christopher's Hospital for Children

Heart transplantation has become the standard of care for patients with end-stage heart failure. The efficacy and therapeutic advantages of transplantation in the pediatric population have not been fully determined. Between March 1985 and September 1986, nine pediatric heart transplantations were performed; the ages ranged from 39 days to 19 years; weight ranged from 2.3 to 100 kg. The underlying disease was acquired cardiomyopathy (four patients); cardiomyopathy caused by congenital mitral valve disease (two patients); unresectable fibroma of the left ventricle in a newborn (one patient); hypoplastic left heart syndrome (one patient); and hypertrophic obstructive cardiomyopathy (one patient). Initial immunosuppression therapy consisted of cyclosporine, prednisone, and antithymocyte globulin. Recently, newer protocols have evolved through experience. Seven patients survived the perioperative period and had follow-up from 1 to 19 months, for a total of 41 transplant months. Rejection occurred at a rate of 1.4 episodes per month in children compared with 0.8 episodes per month in our adult patients. There was no statistical difference in the number, severity, or timing of rejection episodes in the pediatric versus adult population. Major complications included cyclosporine-induced seizures in two patients, mild hypertension in two, five infectious episodes (three bacterial and two viral), and three late deaths. All children who survived are in New York Heart Association functional class I with no developmental delays. This series is heavily weighted with children (33% less than age 1 year). Early results demonstrate that pediatric and infant heart transplantation is technically practical. Improved results are to be expected with additional experience and further modification of adult protocols to assure patient growth and minimize the high infection rate.

Recurrent obstruction after subclavian flap repair of coarctation of the aorta in infants. Can it be predicted or prevented?

Recoarctation is a problem in some patients after subclavian flap aortoplasty. To investigate the reason for recoarctation, we reviewed the records of 26 infants who underwent subclavian flap repair for symptomatic coarctation of the aorta at less than 3 months of age between June, 1979, and December, 1983. Age at repair ranged from 2 to 65 days (median 16 days) and weight from 2.1 to 4.9 kg (median 3.4 kg). In 14 patients the coarctation was associated with significant intracardiac defects (complex in six). There were two intraoperative deaths and one early death (surgical mortality 12%). The survivors were followed from 6 weeks to 66 months (median 12 months). Five survivors (22%), all operated on at less than 14 days of age, developed severe recoarctation 6 weeks to 6 months (median 5 months) after repair. The obstruction appeared to be due to lumen obliteration by shelf-life posterior wall tissue. Morphometric analysis of preoperative angiograms showed no correlation between recoarctation and distance between the left subclavian artery and the site of coarctation, length of the isthmus, diameter of the isthmus, combined cross-sectional area of the left subclavian artery and isthmus, or the ratio of the combined cross-sectional area of the left subclavian artery and isthmus to the cross-sectional area of the descending thoracic aorta. Recoarctation did not correlate with weight at operation, but it correlated significantly with age at aortoplasty (p = 0.02). The results suggest that intrinsic abnormalities of the periductal aortic wall are responsible for recoarctation after subclavian flap aortoplasty. Particular attention to this abnormal tissue at repair may prevent early recurrence in young infants.

Aneurysm of main pulmonary artery in a neonate with airway obstruction and heart failure: long-term survival after pulmonary artery aneurysmectomy and patent ductus arteriosus ligation

A neonate was seen with complete atelectasis of the left lung secondary to compression of the left main bronchus by a congenital aneurysmal main pulmonary artery. Operation consisted of pulmonary artery aneurysmectomy and ligation of an associated patent ductus arteriosus. Follow-up (3 years after operation) demonstrated complete resolution of the atelectasis and congestive heart failure.

Vascular rings and slings: long-term follow-up of pulmonary function

Between 1968 and 1983, 54 patients underwent surgery for symptomatic aortic arch and pulmonary artery anomalies at St Christopher's Hospital for Children. Presenting symptoms included stridor, wheeze, apnea, recurrent pulmonary infections, or dysphagia. Diagnosis was established with chest roentgenogram, bronchoscopy, barium esophagram, and arteriography. Four types of vascular anomalies were encountered; double aortic arch (24 patients), right aortic arch with left ligamentum arteriosum (17 patients), anomalous innominate artery (10 patients), and pulmonary artery sling (three patients). There were no intraoperative deaths and only one postoperative death. All surviving patients had immediate relief of their severe respiratory or swallowing symptoms. Mild respiratory symptoms persisted postoperatively from 3 months to 4 years and included frequent or severe upper respiratory infections, persistent cough, stridor and pneumonia. Five of the 53 surviving patients were lost to follow up. The remaining 48 patients were followed from 6 months to 14 years and all but one patient noted complete resolution of all respiratory symptoms. Twenty-nine patients at follow up were old enough to undergo pulmonary function testing including vital capacity, functional residual capacity, and inspiratory and expiratory flow volume loops. Seventeen of these 29 asymptomatic patients consented to these studies, and nine of these patients had abnormal flow volume loops indicative of significant central airway obstruction; the other eight studies were normal. We conclude that surgical repair for vascular rings and slings is safe and symptomatically efficacious. However, anatomic tracheal or bronchial distortion persists in a significant number of these patients as evaluated by pulmonary function studies.

Congenital cardiac anomalies associated with the DiGeorge syndrome: a neonatal experience

The DiGeorge syndrome is a rare congenital abnormality of absent of hypoplastic thymus and parathyroid glands. Thirty neonates who had cardiac lesions and the DiGeorge syndrome are reviewed. The early mortality for 10 neonates undergoing palliative procedures was 80%. Seventy-five percent of the deaths were secondary to sepsis. Twenty neonates did not undergo palliative procedures. In this group, early mortality was 60% and late mortality was 65%. Sixty percent of the deaths in this group were associated with sepsis, with cardiac failure responsible for the remaining deaths. Survival in both groups has improved with appropriate treatment of the immunological and metabolic consequences of the DiGeorge syndrome.

Pulmonary resection for complications of cystic fibrosis

Pulmonary sequelae account for a large proportion of the morbidity and mortality of cystic fibrosis. Bronchiectasis, hemoptysis, and abscess formation are often not responsive to conservative medical therapy. Pulmonary resection in selected cystic fibrosis patients is safe and therapeutically rewarding. Eleven pulmonary resections in ten patients with cystic fibrosis were performed. Patients ranged from 2.5 to 19 years of age. Indications for resection were: (1) abscess and bronchiectasis (nine patients), (2) atelectasis and mass (one patient), and (3) life-threatening hemorrhage (one patient). Surgical resection was employed only for medically refractory lesions which were life-threatening or contaminated otherwise functional lungs. Resection was limited to the most severely diseased areas, sparing functional lung parenchyma when possible. In this series, 9 lobectomies, 1 pneumonectomy, and 1 segmentectomy were performed. Preoperative management included aggressive chest physiotherapy and postural drainage, rigid bronchoscopic lavage, and broad-spectrum parenteral antibiotics. All patients were extubated in the operating room immediately postoperatively. Tracheostomy was not employed. There were no perioperative complications. All patients experienced subjective improvement. Objectively, improvement following surgical resection included: decreased cough and sputum production, and decreased incidence of exacerbations of pulmonary infections. Limited pulmonary resection when combined with intensive preoperative pulmonary toilet is a safe adjunct in the treatment of bronchiectasis and hemoptysis secondary to cystic fibrosis. Pulmonary resection should be limited to only severely destroyed lung parenchyma which is refractory to medical management. In contradistinction to other authors we have not found tracheostomy a necessary adjunct in surgical management.

Vasovagal syncope in children requiring pacemaker implantation

Four children presented with episodic loss of consciousness. Two of the children were siblings. Neurologic causes were initially suspected in all but extensive evaluations and EEGs excluded seizures. ECGs in one patient demonstrated first- and second-degree AV block and first-degree AV block in another. The QT and QTc intervals were normal in all. Eyeball pressure in all patients produced profound bradycardia. All patients became asymptomatic after the implantation of pacemakers, although one died 15 months afterward from another cause.

Obstruction of the airway by the aorta: an observation in infants with congenital heart disease

Obstruction of the airway by a dilated aorta was observed in four infants who had complex congenital heart defects as follows: two infants had a tetralogy of Fallot and pulmonary atresia; one infant had a truncus arteriosus type 1 and small branched pulmonary arteries; and one infant had a dextroversion of the heart with a right aortic arch, single atrium, single ventricle, transposition of the great vessels, and severe subpulmonic obstruction. In addition to the extrinsic compression of the airway by the large aorta, intrinsic anomalies of the trachea and at times the main bronchi were observed at autopsy in three of the four infants. The compression of the trachea is readily apparent on lateral radiographs of the chest.

Palliative repair of transposition of the great arteries with criss-cross heart: ventricular septal defect and hypoplastic right (systemic) ventricle

Four cases of palliative Mustard or Senning repair for transposition of the great arteries (TGA) with ventricular septal defect (VSD), hypoplastic right ventricle, and superior-inferior ventricular configuration are presented. The palliative Mustard procedure-a Mustard repair without VSD closure-is usually reserved for patients with pulmonary vascular obstructive disease (PVOD). In such cases, VSD closure would result in left ventricular failure. Each of our four patients had normal or only slightly elevated pulmonary resistance (1.0 to 5.2 Wood units). However, in each case a hypoplastic right ventricle precluded VSD closure. All four patients had transposition-like hemodynamics with unfavorable streaming to the great arteries, despite the fact that two patients had a levo arterial configuration. In each case, the ventricular relationship included a hypoplastic, superior right ventricle with a horizontal ventricular septum-the so-called "upstairs-downstairs" or "superior-inferior" heart. All patients had previous balloon atrial septostomy or open septectomy to improve atrial mixing. Two patients had previous pulmonary artery banding because of increased pulmonary flow. All four patients remain survivors of the palliative Mustard or Senning repair, which was performed at 10 months, 5 1/2, 12, and 16 years. In each case, there was a marked improvement of symptomatology with a decrease of hemoglobin (mean 21.1 gm/dl preoperatively to 15.3 gm/dl postoperatively) and an increase of arterial oxygen saturation (mean 78 vol % preoperatively to 93 vol % postoperatively). This is the first palliative Mustard or Senning repairs in patients with TGA, VSD, and hypoplastic right ventricle without PVOD. The procedure produces gratifying palliation for these patients.

Pseudomonas maltophilia bacteremia in children undergoing open heart surgery

Pseudomonas maltophilia was isolated from intraoperative blood cultures in eight of 13 children undergoing open heart surgery during a five-week period. Antibiograms were identical and included resistance to prophylactic antibiotics. The source of the outbreak was traced to contamination of both the calibration device used on the pressure monitoring system and the sensor surface of transducers used in this system. In a mock system, calibration with a contaminated device resulted in recovery of the organism from transducer dome fluid. Dye studies confirmed the integrity of the transducer membrane but demonstrated reflux of dome fluid into the monitoring line fluid. A case-control study revealed no patient- or surgery-related factors predisposing to P maltophilia bacteremia and no excess of morbidity or mortality in patients as a result of bacteremia. The outbreak was confined to patients undergoing open heart surgery and was terminated abruptly by sterilization of transducers and revision of the calibration device.

A modified intracardiac patch holder

A new intracardiac patch holder is described. This instrument facilitates the suturing of prosthetic patches.