[Auriculo temporal nerve. Neuroanatomic bases of the Frey's syndrome]. / El nervio auriculotemporal. Bases neuroanatómicas del síndrome de Frey.

The aim of this study was to precise the relationships of the auriculotemporal nerve in the infratemporal and parotid regions. We realized micro-dissections of thirty-two infratemporal and parotid regions of human cadaver's formol-fixed. The pattern of origin was: one root: 15.4%, two roots: 73.1%, three roots: 11.5%. In all cases, the lateral root present the major diameter (2-2.5 mm). In those cases with two roots, these formed a neural loop round the middle meningeal artery in the 89.4% of the cases. The origin of the medial root was the posterior border of the inferior alveolar nerve. The median distance between the lateral root and the temporomandibular joint capsule was 1.5 mm, with asymmetric pattern: right: 2 mm (rank: 0-7 mm; ED: 1.90 mm); left: 1.25 mm (rank: 0-3 mm; ED: 0.88 mm). In 10 cases (31.3%) the lateral root was in direct contact with the articular capsule, with asymmetric pattern: left: 46.1%; right: 21%. The median distance between the superior aspect of the articular disk and the trunk of the auriculotemporal nerve in the posterior aspect of the temporomandibular joint was 10,5 mm (ED: 4.06 mm), with asymmetric pattern: right: 9 mm (rank: 5-18.0 mm; ED: 3.70 mm); left: 11.0 mm (rank: 3.0-20 mm; ED: 4.41 mm). We discussed the rol of this findings in the etiology of the Frey's syndrome.

El nervio auriculotemporal. Bases neuroanatómicas del Síndrome de Frey / Auriculo temporal nerve. Neuroanatomic bases of the Frey´ Syndrome

El propósito de este estudio fue precisar las relaciones del nervio auriculo temporal en las regiones infratemporal y parotídea. Se realizó la microdisección de 32 regiones infratemporales y parotídeas de cadáveres humanos formolados. Los patrones de origen fueron: raíz única: 15.4%, dos raíces: 73.1% y tres raíces: 11.5%. En todos los casos la raíz lateral era la de mayor diámetro (2-2,5 mm). En los casos con dos raíces estas constituían un ojal nervioso a la arteria meníngea media en el 89.4% de los casos. La raíz medial se originaba en todos los casos del borde posterior del segmento inicial del nervio alveolar inferior. La distancia media entre la raíz lateral del nervio auriculotemporal y la cápsula dela articulación temporo mandibular fue de 1.5 mm, con patrón asimétrico, derecha: 2 mm (rango: 0-7 mm; DE1.90 mm); izquierda: 1.25 mm (rango: 0-3 mm; DE 0.88mm). En 10 casos (31.3%) la raíz lateral se encontraba en contacto directo con la cápsula articular, izquierda (46.1%) y a derecha (21.1%). La distancia media en la cara posterior de la articulación temporomandibular, desde la cara superior del disco articular al tronco del nervio auriculo temporal fue de 10,5 mm (DE: 4.06 mm),con patrón asimétrico, derecha: 9 mm (rango: 5,0-18,0mm; DE 3,70 mm), izquierda: 11.0 mm (rango: 3.0-20.0mm; DE 4.41 mm). Se discute el rol de estos hallazgos en la etiología del síndrome de Frey

The aim of this study was to precise the relationships of the auriculo temporal nerve in the infratemporal and parotid regions. We realized micro-dissections of thirty–two infratemporal and parotid regions of human cadaver’s form ol-fixed. The pattern of origin was: one root: 15.4%, two roots: 73.1%, three roots: 11.5%. In all cases, the lateral root present the major diameter(2-2,5 mm). In those cases with two roots, these formed a neural loop round the middle meningeal artery in the 89.4% of the cases. The origin of the medial root was the posterior border of the inferior alveolar nerve. The median distance between the lateral root and the temporo mandibular joint capsule was 1.5 mm, with a symmetric pattern: right: 2 mm (rank: 0-7 mm; ED:1.90mm); left: 1.25 mm (rank: 0-3 mm; ED: 0.88 mm).In 10 cases (31.3%) the lateral root was in direct contact with the articular capsule, with asymmetric pattern: left: 46.1%; right: 21%. The median distance between the superior aspect of the articular disk and the trunk of the auriculo temporal nerve in the posterior aspect of the temporo mandibular joint was 10,5 mm (ED: 4.06 mm), with asymmetric pattern: right: 9 mm (rank: 5-18.0 mm; ED: 3.70 mm); left: 11.0 mm (rank: 3.0-20mm; ED: 4.41 mm). We discussed the rol of this findings in the etiology of the Frey’s syndrome

Modified extended end-to-end repair of coarctation in neonates and infants.

Although the classic extended end-to-end repair is the procedure of choice in most neonates and infants with coarctation of the aorta, there is a problem of distance despite extensive mobilization and impairment of growth of the arch because of scarring in some patients. Since December 1999, 15 neonates and infants without significant arch hypoplasia have undergone a modified extended end-to-end repair of coarctation of the aorta at our institution. The anastomosis was performed between the posterior wall of the isthmus and base of the subclavian artery and anterior wall of the descending aorta, resulting in an anastomosis that was usually 1(1/2) times the diameter of the descending aorta. All patients survived and were followed up to 57 months (average, 34). Two patients developed significant gradients 3 months and 1 year postoperatively, respectively, probably from luxurious tissue growth at the suture line. Both were treated successfully with balloon dilatation. The modified extended end-to-end repair provides another option for repair of coarctation in neonates and infants. It requires less mobilization of the arch and descending aorta. It is particularly useful in patients with long isthmus.

Annular and leaflet augmentation in Noonan's syndrome with dysplastic pulmonary valve.

Two patients with dysplastic pulmonary valves associated with Noonan's syndrome successfully underwent leaflet augmentation with pericardial membrane and annular enlargement with preservation of valve competence. Both patients are doing well at 36 and 37 months, respectively, postoperatively. Echocardiography and clinical assessment showed gradients of 12 and 16 mmHg, respectively, and negligible pulmonary valve insufficiency. The surgical technique is simple and provides an attractive alternative in patients with dysplastic pulmonary valve and small pulmonary orifice and annulus.

Intraatrial mitral valve insertion with native valve preservation in children.

Two patients underwent intraatrial mitral valve insertion for an unsuccessful valvotomy for severe mitral stenosis and left-sided atrioventricular valve insufficiency associated with corrected transposition utilizing a porcine valve from a valved conduit with preservation of the native valve. The valves were inserted using continuous suture distally at the mitral annulus and proximally at the pulled atrial wall distal to the pulmonary veins. Both patients had uneventful hospital course and are doing well at up to 6 months postoperatively. This approach provides a viable option for congenital mitral stenosis or insufficiency in children.

Extended end-to-end repair and enlargement of the entire arch in complex coarctation.

BACKGROUND: Treatment of hypoplasia of the entire arch in coarctation is a surgical challenge. The current approaches have technical difficulties, high recurrence rates, and increased morbidity and mortality. METHODS: Over a 14-month period, a combined extended end-to-end repair with patch enlargement of the concavity of the entire arch was performed in 6 neonates and 1 infant. Through a midsternotomy and using cardiopulmonary bypass and hypothermia, extended end-to-end repair was performed initially leaving the proximal anastomosis open. The enlarging polytetrafluoroethylene patch was then sutured starting at the incised descending aorta distal to the extended end-to-end repair and continued retrogradely through the transverse arch to the ascending aorta proximal to the aortic cannulation site. One neonate had a patent ductus arteriosus and another had ventricular septal defect closure. One neonate had arterial switch and 3 had Norwood-type procedures performed with the enlarging patch extended to the pulmonary artery anastomosis. The remaining infant had arch enlargement performed after an arterial switch procedure and extended end-to-end repair. RESULTS: All patients did well and showed no residual gradient up to 1 year follow-up. Two patients successfully had bidirectional Glenn shunt at 9 months of age, and one had closure of residual arterial septal defect at 8 months of age. CONCLUSION: The combined extended end-to-end repair and arch enlargement procedure should minimize recurrence rates because of a tension-free enlargement of the entire aortic arch and elimination of the coarctation ridge and ductile tissues. Combined with the arterial switch and Norwood-type procedures, the approach results in a large neoaorta.

Semilunar valve switch procedure: autotransplantation of the native aortic valve to the pulmonary position in the Ross procedure.

BACKGROUND: The Ross procedure has gained wide acceptance in young patients with aortic valve disease. The durability of the pulmonary autograft in the aortic position has been proved, with up to 24 years of follow-up. The homograft pulmonary valve, however, has limited longevity. To circumvent this problem we harvested, repaired, and reimplanted the native aortic valve with intact commissures in the pulmonary position in 13 patients undergoing the Ross procedure for aortic insufficiency. METHODS: The cause of aortic insufficiency was rheumatic in 6 patients, congenital in 4, post-aortic valvotomy in 2, and bacterial endocarditis in 1. Patient age ranged from 5 to 45 years (mean, 17+/-9 years). Root replacement technique with coronary artery reimplantation was used. In the first 4 patients, the native aortic valve was sutured into the right ventricular outflow tract, and a polytetrafluorethylene patch was used to reconstruct the main pulmonary artery. In the last 9 patients, the aortic valve and polytetrafluorethylene patch were made into a conduit by another surgeon while the left-sided reconstruction was performed. RESULTS: All patients had marked reduction of left ventricular dilation and good function of the reimplanted native aortic valve, with up to 50 months of follow-up (mean, 29.9+/-14.2 months; range, 12 to 50 months). Two patients died 15 and 26 days, respectively, of a false aneurysm rupture at the distal aortic anastomosis. In the remaining 11 patients, 9 (82%) had mild or absent, and 2 (18%) had mild to moderate, neoaortic valve regurgitation. Similarly, 9 patients (82%) had mild or absent, and 2 (18%) had mild to moderate, neopulmonary valve regurgitation. Mild neopulmonary valve stenosis was present in 6 patients (54%) (mean gradient, 29+/-4 mm Hg; range, 25 to 35 mm Hg). All surviving patients are in functional New York Heart Association functional class I. CONCLUSIONS: We conclude that use of the native aortic valve with the Ross procedure makes the procedure attractive and potentially curative. The diseased aortic valve works well in the pulmonary position because of lower pressure and resistance. The valve leaflets should remain viable and grow in both the pulmonary and aortic positions because they derive nutrition directly from the blood.

The pericardial membrane pulmonary monocusp: surgical technique and early results.

Long-term pulmonary insufficiency resulting from simple transannular patching of the right ventricle outflow tract will ultimately lead to deterioration in right ventricular function. Previously, monocusps constructed from xenografts, homografts, fascia lata, and autologous pulmonary artery wall have been utilized to minimize pulmonary regurgitation and its deleterious effect on right ventricular function. However, these tend to degenerate in the long term, necessitating reoperation. To circumvent this problem we have used a monocusp constructed from 0.1-mm polytetrafluorethylene (PTFE, pericardial membrane) clinically demonstrated to be resistant to issue ingrowth and degeneration. Seven children (5 tetralogy of Fallot, 2 pulmonary stenosis) who required division of a small pulmonary annulus underwent monocusp construction with 0.1-mm PTFE. Three patients had previous corrective surgery. One of these patients had a bovine pericardial monocusp placed 8 years previously, which degenerated. Of the remaining two patients, one had a pulmonary valvotomy as a neonate, the other repair of tetralogy of Fallot with a transannular patch. At a mean (+/- standard deviation) follow up to 17+/-5.8 months all patients are alive and are New York Heart Association (NYHA) Class I. Echocardiography demonstrates mild pulmonary insufficiency (PI) in 2 patients, mild to moderate PI in 4, and moderate to severe PI in 1. The presence of a pericardial membrane monocusp in the pulmonary position may, in the long term, prevent the deleterious effects of transannular patching on right ventricular dysfunction and be more resistant to degenerative changes characteristic of monocusps constructed of native pericardium or allogeneic tissue.

Experimental evidence of cerebral injury from profound hypothermia during cardiopulmonary bypass.

Choreoathetosis, seizures, and impaired mental development continue to occur in children undergoing cardiopulmonary bypass (CPB) and profound hypothermia with or without circulatory arrest. Although there is some evidence that the hypothermia itself may be causing these neurologic problems, skepticism remains because of lack of evidence from experimental studies simulating the clinical setting. In this experimental study, we examined the effect of profound and moderate hypothermia on the brain while maintaining normal flow rates during CPB. Ten adult mongrel dogs equally divided into two groups were anesthetized and subjected to CPB and varying levels of hypothermia (group 1, < or = 15 degreesC; group 2, < or = 2 degreesC). Both groups were kept at the desired temperature for 1 hour prior to rewarming and discontinuation of CPB. The dogs were euthanized 4-6 weeks later and neuropathologic studies were performed. The mean CPB flow rates during cooling and at the desired rectal temperature were comparable in both groups: group 1, 108 +/- 10 ml/kg/min versus 106 +/- 7 ml/kg/min in group 2 (p = NS) and 95 +/- 12 ml/kg/min in group 1 versus 101 +/- 5 ml/kg/min in group 2 (p = NS). Because of the difference in temperature between the two groups, the mean cooling time (onset of CPB to desired rectal temperature) was longer in group 1 (70 +/- 14 minutes) than in group 2 (28 +/- 11 minutes, p = 0.007). Hence, the total mean CPB time was also longer in group 1 (198 +/- 25 minutes) than in group 2 (143 +/- 13 minutes, p = 0.002). The lowest mean blood and rectal temperature achieved in group 1 were 11 +/- .9 degreesC and 12 +/- 1 degreesC versus 29 +/- .4 degreesC (p < 0.001) and 30 +/- .6 degreesC (p = 0.001), respectively, in group 2 (p = 0.001). Neuronal loss and degeneration was noted in all dogs in group 1 ranging from 2 to 8 cells per 1000 cells counted compared to none in group 2 (p = 0.05). These lesions occurred in both the basal ganglia and the cortex, although they were more marked in the caudate when compared to the cortex and cerebellum. Both in the cortex and in the caudate, neuronal loss was more marked around the capillaries. We conclude that the use of profound hypothermia of < or =15 degreesC and maintenance of normal flow rates during cooling at this temperature for 1 hour produces neuronal loss and degeneration in the brain. These lesions being more marked around capillaries points to the vulnerability of the neurons, probably because of their high lipid content to injury from the cold perfusate.

Modified Konno-Rastan procedure for subaortic stenosis: indications, operative techniques, and results.

BACKGROUND: Diffuse or unresectable subaortic stenosis (SAS) necessitates an aggressive surgical approach for the elimination of left ventricular outflow tract obstruction. In this article we report our experience with the modified Konno-Rastan procedure, with inherent preservation of the native aortic valve and annulus, in the treatment of diffuse or unresectable SAS. METHODS: Sixteen children (age range, 21 months to 18 years) underwent the modified Konno-Rastan procedure through either a transventricular (n = 12) or a transatrial approach (n = 4) to the conal septum. Indications for operation were recurrent SAS (n = 3), hypertrophic obstructive cardiomyopathy (n = 3), tunnel stenosis (n = 2), SAS related to a canal (n = 3), and SAS after ventricular septal defect closure (n = 5). Eleven patients had undergone previous procedures and 5 underwent the modified Konno-Rastan procedure as their primary operation. RESULTS: The mean preoperative left ventricular outflow tract gradient of 50 +/- 17 mm Hg was reduced to 3 +/- 7 mm Hg (p < 0.001) after surgical repair. Postoperative complications included sternal infection (n = 1), heart block (n = 2), mediastinal bleeding (n = 1), and renal and cerebral ischemia (n = 1). There was 1 late postoperative death caused by pneumonia 2 years after operation (6.2% mortality rate). The mean follow-up period was 62 +/- 39 months and all patients had complete relief of preoperative symptoms and were in New York Heart Association class I. One patient underwent a successful redo modified Konno-Rastan procedure 7 years after the first operation for residual left ventricular outflow tract obstruction immediately below the aortic valve. One patient is awaiting reoperation for aortic incompetence unrelated to conal enlargement 1.5 years after the first procedure. CONCLUSIONS: The modified Konno-Rastan procedure represents an excellent therapy for diffuse or unresectable SAS in patients with a normal aortic valve. In addition, it produces excellent results in a limited number of patients with hypertrophic obstructive cardiomyopathy, in whom the Morrow procedure traditionally has been performed. Although it usually is performed through a transventricular approach, the modified Konno-Rastan procedure also can be performed through a transatrial approach; this is particularly useful in patients who have had previous ventricular septal defect closure associated with SAS occurring proximal to the prosthetic patch.

Anomalous right coronary artery from the pulmonary artery in Taussig-Bing anomaly.

The presence of associated anomalies in patients with double-outlet right ventricle can significantly alter surgical intervention. Preoperative delineation of these anomalies can facilitate surgical planning and improve outcome. We describe a case in which the right coronary artery and anterior descending coronary artery arose from the pulmonary artery in a patient with double-outlet right ventricle with subpulmonary ventricular septal defect (Taussig-Bing anomaly). Recognition of this important anomaly prevented significant intraoperative myocardial damage by altering techniques of cardioplegia administration for myocardial preservation.

Simultaneous repair of pectus excavatum and congenital heart disease.

Most repair of heart lesions and pectus deformity has been performed in adult patients using long incisions, sternal splits, excision of deformed cartilages, and sternal turnover operations that could result in poor cosmesis and chest growth in children because of sternal devascularization. We performed simultaneous pectus repair and atrial septal defect closure in 2 children using a short longitudinal incision and avoiding a transverse or longitudinal sternal split. After extraperichondrial excision of the deformed cartilages and mobilization of the sternum from the neurovascular bundles, a transverse wedge of sternum was removed at the level of the third cartilages, allowing cephalad retraction of the sternum and providing excellent exposure for the intracardiac operation. The cosmetic appearance remains excellent in both patients at 1 and 4 years postoperatively.

Fenestrated fontan procedure: evolution of technique and occurrence of paradoxical embolism.

The Fenestrated Fontan procedure (FFP) has improved outcome in high risk patients. The technique is evolving, however, and complications are not fully known. Over a 3-year period 13 patients (mean age 35 +/- 29 months) underwent an FFP in our institution. In the first two patients the fenestration had to be created because of high right atrial pressure and low cardiac output; in 11 patients the FFP was planned. In three patients the sutures for the adjustable fenestration were crossing the defect. In 10 patients, purse-string sutures were placed around but not across the defect. Because large fenestrations were created in 11 patients (8-12 mm) Glenn shunts were performed to improve arterial saturation. The postoperative course was relatively uneventful, with chest tubes being removed 1-8 days (mean 4 +/- 3 days) postoperatively and the hospital stay ranging from 7 to 27 days (mean 14 +/- 6 days). One patient had bleeding and another had a mediastinal abscess. The first patient died (7.6%) because of hemodynamic instability due to prolonged cardiopulmonary bypass from the creation and enlargement of the fenestration. One patient had a paradoxical cerebral embolism from clots that formed on the sutures crossing the fenestration. Because of this problem the remaining patients were placed on salicylates while awaiting closure of their fenestration. All 12 patients had their fenestrations closed, performed under local anesthesia in 9, at mediastinal abscess drainage in 1, and spontaneously in 2. We conclude that creation of large fenestrations in combination with Glenn shunts and the use of adjustable fenestrations are viable modifications of the FFP. The use of purse-string sutures around the fenestration and antiplatelet drugs can probably minimize the occurrence of paradoxical embolism.

Cost-effectiveness of transaxillary muscle-sparing same-day operative closure of patent ductus arteriosus.

Transaxillary muscle-sparing patent ductus arteriosus closure performed as same-day surgery is described in 10 patients. This approach provides a superb cosmetic result while obviating the need for thoracostomy tube placement.

Management of arch hypoplasia after successful coarctation repair.

BACKGROUND: Pronounced arch obstruction can be seen after a well-repaired coarctation, and this probably results from the failure of a somewhat hypoplastic arch to grow or from clamp injury at the time of the initial repair, or from both causes. Because of mediastinal adhesions and minimal collateral circulation, use of extraanatomic bypass grafts appears to be the preferred approach. METHODS: Six children or young adults presented with arch obstruction over a 3-year period. Their mean age was 13.5 +/- 4 years, and the mean interval from the time of the initial repair was 10 +/- 4 years. The mean age of the patients at the time of the initial repair was 3.2 +/- 5 years. Symptoms included exertional headache and chest pain. The mean systolic gradients, as shown by echocardiography and cardiac catheterization, were 34 +/- 7 mm Hg and 33 +/- 6 mm Hg, respectively. Repair was accomplished through a midsternotomy using a polytetrafluoroethylene patch placed in the concavity of the arch, which extended from the ascending to the descending aorta. Dissection was kept close to the aorta and arch to minimize injury to the phrenic and recurrent laryngeal nerves. Cardiopulmonary bypass and moderate hypothermia (25 degrees to 27 degrees C bladder temperature) without circulatory arrest were used. RESULTS: All patients were discharged home 4 to 20 days postoperatively (mean, 7 +/- 6 days). All patients were found to be normotensive at a mean follow-up of 1.3 +/- 1 years. Postoperative echocardiograms, which were obtained in all patients, revealed no residual gradients. Exercise blood pressure was evaluated in 2 patients and found to be normal. CONCLUSIONS: Transsternal arch enlargement using cardiopulmonary bypass and moderate hypothermia without circulatory arrest is an attractive and safe approach for the treatment of arch obstruction after coarctation repair. Unlike the use of extraanatomic bypass grafts, it allows complete relief of the obstruction, unhampered aortic growth, the minimal use of foreign material, and a repair that is protected deep within the mediastinal space.

Recognition and management of obstructed pulmonary veins draining to the coronary sinus.

BACKGROUND: Obstruction of the pulmonary veins in total anomalous pulmonary venous drainage to the coronary sinus is generally considered rare. However, if it is present, the usual treatment of unroofing the coronary sinus will lead to a poor result. METHODS: Four patients with total anomalous pulmonary venous drainage to the coronary sinus with obstruction were identified over a 14-month period. Three patients in whom the diagnosis of obstruction was not made underwent coronary sinus unroofing. Retrospective review of the preoperative echocardiograms and Doppler studies showed the presence of obstruction in the vertical vein in 2 patients and in the branches in the other. In the fourth patient, obstruction in the vertical vein was recognized preoperatively with echocardiography and Doppler study. This patient underwent direct common pulmonary vein-left atrial anastomosis. RESULTS: All 3 patients who had coronary unroofing were seen with obstructed pulmonary veins 2 to 7 months postoperatively. After reoperation, 1 died, and the other 2 have done relatively well 3 1/2 and 15 months postoperatively. The patient who had an anastomosis between the common pulmonary vein and the left atrium is doing well 18 months postoperatively. CONCLUSIONS: Obstruction in total anomalous pulmonary venous drainage to the coronary sinus is not as rare as previously reported. To improve outcome, its presence should be sought using complete echocardiography including Doppler studies. When obstruction is present, transection of the vertical vein and common pulmonary vein-left atrial anastomosis through the superior approach is an attractive technique that also eliminates the right-to-left shunting associated with coronary sinus unroofing and simplifies closure of the atrial septal defect.

Anatomic correction of dextrotransposition of the great arteries in a 36-year-old patient.

During the 1960s, the Mustard or Senning operation was the conventional palliative therapy for patients with transposition of the great arteries. Many of these patients are now adults, and the durability of the morphologic right ventricle to function as the systemic ventricle is being questioned. Surgical options for such adult patients have traditionally been limited to cardiac transplantation. More recently, an arterial switch operation with take-down of the Mustard or Senning baffles has been reported. Herein we describe the clinical course of a 36-year-old woman who underwent a successful single-stage Mustard take-down, atrial reconstruction, and arterial switch operation.

Perinatal myocardial infarction in a newborn with a structurally normal heart.

Myocardial infarction in a newborn infant in the absence of congenital heart disease and anomalous coronary artery anatomy is extremely rare. We report a case of a newborn with a structurally normal heart who presented shortly after birth with congestive heart failure and cardiovascular collapse suggestive of a hypoplastic left ventricle or critical aortic stenosis. This newborn had a massive myocardial infarction caused by thromboembolic occlusion of the left main coronary artery. Clinical, laboratory, and autopsy data suggest the event occurred in utero.

Clinical improvement after revision in Fontan patients.

BACKGROUND: Arrhythmias, decreased exercise tolerance, or malabsorption will develop in a significant number of Fontan patients. Fontan revision consisting of creation of lateral atrial tunnel, reconnection of the Glenn shunt when present, or both appears to improve these patients. METHODS: Over a 34-month period, 9 patients underwent Fontan revision. The mean age was 11 +/- 5 years and the mean interval from Fontan operation to revision was 3 +/- 2 years. The reason for revision included marked impairment in exercise capacity, inability to go to school consistently, and chronic fatigue in 6 patients, 3 of whom also had serious atrial arrhythmias. Five of the 6 patients had a classic Glenn shunt. The mean right atrial pressure was greater than the pressure of the Glenn shunt (20 +/- 1.6 versus 17 +/- 0.8 mm Hg). Three of the 6 patients also showed a significant gradient between the right or left pulmonary artery wedge and ventricular end-diastolic pressure, indicating pulmonary vein obstruction from the bulging atrial septum or partitioning patch (13 +/- 3 versus 6.8 +/- 1 mm Hg). The remaining 3 patients had revision because of malabsorption (1), hepatomegaly and obstructed right pulmonary veins from bulging atrial septum (1), and tricuspid insufficiency (1). Fontan revision was accomplished with creation of a lateral atrial tunnel and Glenn reconnection in 6 patients, Glenn reconnection in 2, and creation of a lateral atrial tunnel in 1. Four patients had additional procedures. RESULTS: One patient died of Pseudomonas pneumonia. Early extubation, chest tube removal, and postoperative hospital discharge were accomplished in 8 patients (mean = 1.4 +/- 1, 2.8 +/- 1, and 8 +/- 3 days, respectively). One patient died 8 months postoperatively of brain damage after ventricular fibrillation from attempted cardioversion for atrial flutter. The remaining patients had marked improvement in exercise capacity with ability to consistently go to school, improvement in duration and tolerance to arrhythmias on less medication, and resolution of malabsorption up to 37 months postoperatively (mean, 20 +/- 12 months). CONCLUSIONS: We conclude that creation of lateral atrial tunnel with excision of a bulging atrial septum or atrial partitioning patch that causes pulmonary venous obstruction, reconnection of the Glenn shunt, which allows better distribution of flow based on the pulmonary vascular bed and resistance of each lung, or a combination of these procedures will improve Fontan patients.

The structural organization of the human skeletal muscle ryanodine receptor (RYR1) gene.

The RYR1 gene encoding the Ca2+ release channel of human skeletal muscle sarcoplasmic reticulum has been cloned and exon/intron boundaries have been determined, together with a minimum of 30 bp of intron sequence flanking each splice junction. The gene contains 106 exons, of which two are alternatively spliced. The length of the gene, determined by the alignment of 16 genomic phage clones, a cosmid clone, and several long polymerase chain reaction products, is approximately 160 kb. Exons range from 15 to 813 bp, while introns range from 85 to about 16,000 bp. Analysis of the gene has confirmed published errors in the human RYR1 cDNA and confirmed the structure of two alternatively spliced exons. The numbering of the nucleotides comprising the RYR1 cDNA and the numbering of amino acids encoded by them were corrected to account for these earlier errors and omissions. Analysis of 2.4 kb of the 5' upstream sequence indicated the presence of a CCAAT box and several Sp1 binding sites between nucleotides -200 and -60 bp, flanking the proposed transcription start site at -130 bp. Several other potential transcription factor binding sites were identified throughout the 5' sequence. Knowledge of the structure of the RYR1 gene will provide an invaluable resource for the discovery of mutations in the gene that are causal of human malignant hyperthermia and central core disease.