Central nervous system plasticity during hair cell loss and regeneration

Following cochlear ablation, auditory neurons in the central nervous system (CNS) undergo alterations in morphology and function, including neuronal cell death. The trigger for these CNS changes is the abrupt cessation of afferent input via eighth nerve fiber activity. Gentamicin can cause ototoxic damage to cochlear hair cells responsible for high frequency hearing, which seems likely to cause a frequency-specific loss of input into the CNS. In birds, these hair cells can regenerate, presumably restoring input into the CNS. This review summarizes current knowledge of how CNS auditory neurons respond to this transient, frequency-specific loss of cochlear function. A single systemic injection of a high dose of gentamicin results in the complete loss of high frequency hair cells by 5 days, followed by the regeneration of new hair cells. Both hair cell-specific functional measures and estimates of CNS afferent activity suggest that newly regenerated hair cells restore afferent input to brainstem auditory neurons. Frequency-specific neuronal cell death and shrinkage occur following gentamicin damage to hair cells, with an unexpected recovery of neuronal cell number at longer survival times. A newly-developed method for topical, unilateral gentamicin application will allow future studies to compare neuronal changes within a given animal.

Osteocutaneous radial forearm free flaps. The necessity of internal fixation of the donor-site defect to prevent pathological fracture

BACKGROUND

Osteocutaneous radial forearm free flaps have fallen from favor due to pathological fractures of the radius. The purposes of this study were to propose a means to decrease the rate of pathological fracture by prophylactic fixation of the donor-site defect and to evaluate this technique biomechanically.

METHODS

Two groups of ten matched pairs of fresh-frozen cadaveric radii were harvested. In Group 1, an eight-centimeter length of radius comprising 50 percent of the cross-sectional area of the bone was removed to simulate an osteocutaneous radial forearm donor-site defect. This defect was created in one member of each pair, with the other bone in the pair left intact. In Group 2, both members of the ten matched pairs of radii had identical defects created as previously described. However, one radius in each pair had a twelve-hole, 3.5-millimeter dynamic compression plate placed across the segmental defect. In each group, five matched pairs were tested to failure in torsion and five matched pairs were tested to failure in four-point bending.

RESULTS

In Group 1, the intact radius was a mean of 5.7 times stronger in torsion and 4.2 times stronger in four-point bending than the radius with the segmental resection. In Group 2, the radius that was ostectomized and fixed with a plate was a mean of 4.0 times stronger in torsion and 2.7 times stronger in four-point bending than the ostectomized radius.

CONCLUSIONS

Removal of an eight-centimeter segment from the radius dramatically decreased both torsion and bending strength. Application of a plate over the defect in the radius significantly restored the strength of the radius (p = 0.01).

Tonotopic changes in 2-deoxyglucose activity in chick cochlear nucleus during hair cell loss and regeneration

Following cochlear ablation, auditory neurons in the central nervous system (CNS) undergo alterations in morphology and function, including neuronal cell death. The trigger for these CNS changes is the abrupt cessation of eighth nerve fiber activity. Gentamicin can cause ototoxic damage to cochlear hair cells responsible for high frequency hearing. In birds, these hair cells can regenerate. Therefore, gentamicin causes a partial, yet reversible insult to the ear. It is not known how this partial hair cell damage affects excitatory input to the cochlear nucleus. We examined chick cochlear nucleus activity during hair cell loss and regeneration by measuring 2-deoxyglucose (2DG) uptake. Normal animals showed a rostral to caudal gradient of 2DG activity, with higher activity in caudal regions. When hair cells are damaged (2, 5 days), 2DG uptake is decreased in cochlear nucleus. When hair cells regenerate (9, 16, 28 days), 2DG uptake returns to control levels. This decrease and subsequent return of activity only occurs in the rostral, high frequency region of the cochlear nucleus. No changes are seen in the caudal, low frequency region. These results suggest that changes in activity of cochlear nucleus occur at a similar time course to anatomical changes in the cochlea.

Venous valves in the neck: implications for microvascular free flap reconstruction

Successful microvascular free flap reconstruction requires adequate arterial inflow and venous outflow. We report 4 cases that demonstrate the not uncommon occurrence of locating valves in veins during microvascular head and neck reconstructive procedures. Failure to recognize these valves could have compromised the venous anastomosis. The anatomical literature states that veins in the head and neck lack valves, allowing bidirectional blood flow. As a result, there is potential significant flexibility in the selection of recipient veins for the microvascular anastomosis during free flap reconstruction. The unrecognized presence of a venous valve, however, could cause thrombosis of the venous anastomosis and, ultimately, flap failure. This report of venous valves should speak caution to the head and neck microvascular surgeon when he or she is selecting recipient veins in the neck.

Evidence for loss and recovery of chick brainstem auditory neurons during gentamicin-induced cochlear damage and regeneration

It is well documented that damage to the chick cochlea caused by acoustic overstimulation or ototoxic drugs is reversible. Second-order auditory neurons in nucleus magnocellularis (NM) are sensitive to changes in input from the cochlea. However, few experiments studying changes in NM during cochlear hair cell loss and regeneration have been reported. Chicks were given a single systemic dose of gentamicin, which results in maximal hair cell loss in the base of the cochlea after 5 days. Many new hair cells are present by 9 days. These new hair cells are mature but not completely recovered in organization by 70 days. We counted neurons in Nissl-stained sections of the brainstem within specific tonotopic regions of NM, comparing absolute cell number between gentamicin- and saline-treated animals at both short and long survival times. Our data suggest that neuronal number in rostral NM parallels hair cell number in the base of the cochlea. That is, after a single dose of gentamicin, we see a loss of both cochlear hair cells and NM neurons early, followed by a recovery of both cochlear hair cells and NM neurons later. These results suggest that neurons, like cochlear hair cells, can recover following gentamicin-induced damage.

Round window administration of gentamicin: a new method for the study of ototoxicity of cochlear hair cells

Damage to inner ear sensory hair cells after systemic administration of ototoxic drugs has been documented in humans and animals. Birds have the ability to regenerate new hair cells to replace those damaged by drugs or noise. Unfortunately, the systemic administration of gentamicin damages both ears in a variable fashion with potentially confounding systemic drug effects. We developed a method of direct application of gentamicin to one cochlea of hatchling chickens, allowing the other ear to serve as a within-animal control. We tested variables including the vehicle for application, location of application, dosage, and duration of gentamicin exposure. After 5 or 28 days survival, the percent length damage to the cochlea and regeneration of hair cells was evaluated using scanning electron microscopy. Controls consisted of the opposite unexposed cochlea and additional animals which received saline instead of gentamicin. Excellent damage was achieved using gentamicin-soaked Gelfoam pledgets applied to the round window membrane. The percent length damage could be varied from 15 to 100% by changing the dosage of gentamicin, with exposures as short as 30 min. No damage was observed in control animals. Regeneration of hair cells was observed in both the base and apex by 28 days survival.

First report of Hürthle cell carcinoma revealed by octreotide scanning

Octreotide is an 8-chain amino acid analog of somatostatin. Somatostatin and its receptors occur naturally in multiple sites within the body and serve a suppressive role in endocrine hormone release. When octreotide, which has a considerably longer half-life than somatostatin, is combined with a radioactive isotope, receptor-based imaging can be performed to visualize tumors with high concentrations of somatostatin receptors. Tumors of neural crest origin -- pituitary adenomas, islet cell tumors, medullary thyroid carcinomas, pheochromocytomas, carcinoids, and paragangliomas -- all express high levels of somatostatin receptors. We present the first reported positive octreotide scan of a Hürthle cell carcinoma of the thyroid and, more important, discuss the role of octreotide scanning in otolaryngology, which has not yet been reviewed by our literature.

Retrieval of "old" foreign bodies from the cardiovascular system in children

Several techniques have been developed to retrieve catheter and guide wire fragments that have embolized to the heart and pulmonary vasculature. In most instances, retrieval of the embolized fragments is performed soon after the event has occurred. In this report, we summarize our experience with the removal of these fragments in 3 children after a significant amount of time had elapsed since the time of embolization. The embolized catheter and guide wire fragments were removed without any complications. We also describe the techniques used for their removal, and the problems encountered during the removal of these "old" foreign bodies.

Risk factors for pulmonary complications in the postoperative head and neck surgery patient

BACKGROUND

Pulmonary complications are a primary source of increased cost and morbidity in surgically treated head and neck cancer patients. This study investigates potential risk factors related to postoperative pulmonary complications (pneumonia, adult respiratory distress syndrome (ARDS), and prolonged mechanical ventilation) in head and neck cancer patients.

METHODS

Data from 144 major head and neck procedures performed at the University of Washington between 1985 and 1991 were retrospectively reviewed. Univariate and multivariate analysis were used to evaluate preoperative and perioperative variables identified as potential risk factors for postoperative pulmonary complications.

RESULTS

Fifteen percent of patients had a postoperative pulmonary complication, (n = 21: 18 postoperative pneumonia; 2 ARDS; and 4 prolonged ventilation). The most common pneumonia pathogen was Staphylococcus aureus (62%). Univariate analysis identified smoking and weight loss as significant factors associated with pulmonary complications. The variables preoperative blood urea nitrogen, white blood cell count, and operative chest flap closure all approached but did not reach significance. Multivariate analysis of a subgroup of patients identified smoking history and perioperative antibiotic choice as the only independently significant variables.

CONCLUSIONS

Patient smoking history was the primary variable related to postoperative pulmonary problems, with evidence of increasing risk with increased exposure. Other variables added only limited additional risk association information after multivariate analysis.

Third branchial anomalies. Avoiding recurrences

Lateral cervical cysts, sinuses, and fistulas have been described as anomalies of the normal development of the branchial apparatus. Third branchial apparatus anomalies are rare and constitute less than 1% of all such cases. Three cases of third branchial cleft cysts and sinus tracts are presented. Two patients had previously undergone multiple attempts at extirpation. Complete removal of recurrent branchial anomalies is difficult because of scarring and fascial plane disruption. Recurrences were often the result of inadequate excision, possibly of the tract communicating with the piriform sinus. To avoid this we advocate endoscopy prior to initial resection of a suspected branchial cleft anomaly to identify any pharyngeal communication. A combined, simultaneous endoscopic identification of the piriform sinus tract with a lateral external cervical dissection facilitates complete resection. In recurrent cases, wide-field extirpation of the cyst, tract, and scar tissue is necessary to ensure complete removal of the branchial cleft anomaly. A review of the literature and of branchial apparatus embryology is also presented.

Surgical management of total anomalous pulmonary venous connection. Thirty-year trends

BACKGROUND

Reports of surgical correction of total anomalous pulmonary venous connection (TAPVC) over the past 30 years indicate a general improvement in operative survival. However, prevention of late pulmonary venous obstruction continues to be a cornerstone of successful repair. The purpose of the study was to identify factors associated with improvement in perioperative mortality and to determine risk factors for death and reoperation due to pulmonary vein stenosis after repair of TAPVC.

METHODS AND RESULTS

Using univariate and multiple regression analysis, we analyzed risk of early and late mortality and need for reoperation in 105 patients operated on between April 1966 and June 1995. Despite increased frequency of neonatal repair in the most recent time period (29% in 1966 through 1985; 55% in 1991 through 1995, P < .05), operative mortality declined (13% in 1966 through 1985; 0% in 1991 through 1995). The incidence of postoperative pulmonary hypertensive episodes and death related to pulmonary hypertension decreased significantly over the study period (P < .001). Aggressive preoperative elective medical stabilization and prophylaxis of postoperative pulmonary hypertensive episodes may have contributed to this improvement. By univariate analysis, preoperative pulmonary hypertension (P < .02) and preoperative pulmonary vein obstruction (P < .01) correlated with early mortality up to 1990 but not in the past 5 years. Multiple logistic regression analysis showed that only a small pulmonary confluence associated with diffuse pulmonary vein stenosis was an independent risk factor for early (P < .001) and late (P = .01) death as well as need for reoperation (P = .007). Type of TAPVC was not a significant risk factor throughout the three decades of our experience. At a median follow-up of 87 months, late survival was 98% (93 of 95 operative survivors), and all are NYHA class I.

CONCLUSIONS

Improvements on surgical technique as well as preoperative and postoperative management account for the reduction in mortality and need for reoperation for most types of TAPVC. However, the presence of a small venous confluence and diffuse pulmonary vein stenosis remains a risk factor for adverse outcome.

Right ventricular systolic function in adolescents and young adults after Mustard operation for transposition of the great arteries

This study evaluates long-term ( > 10 years since surgery) right ventricular (RV) systolic function in patients who had previously undergone intraatrial baffle surgery for transposition of the great arteries. Studies suggest these patients are clinically stable and lead satisfactory lifestyles, but long-term ventricular performance is not known. Radionuclide angiocardiography was used to estimate RV ejection fraction in 58 patients a mean of 14 years after the Mustard operation. Repeat studies were performed in 32 patients. The absolute RV ejection fraction of 0.53 +/- 0.10 in our patients did not differ from normal values. Nine patients had a value < 0.42, placing them > 2 SDs below normal. Repeat RV ejection fraction decreased from 0.54 +/- 0.11 to 0.51 +/- 0.11 (p < 0.1) in 32 patients, and > 0.10 in 6. Thus, RV ejection fraction was abnormal in 9 of 58 patients (16%) evaluated > 10 years after a Mustard operation. Repeat studies demonstrate worsening in at least 6 of 32 patients (19%). These postoperative Mustard patients require continued evaluation, even in the absence of overt symptomatology.

Effect of local epinephrine on cutaneous bloodflow in the human neck

The effectiveness of local anesthetics is improved by the addition of a vasoconstrictor which increases duration of action and decreases both systemic toxic reactions and local bleeding. Epinephrine, the standard drug for vasoconstriction, has some limitations due to potential dose-related cardiac and local toxic effects. The authors examined the minimal effective epinephrine concentration required for maximal cutaneous vasoconstriction in the human subject so as to limit potential dose-related side effects. In a randomized, double-blinded prospective study, 23 patients undergoing head and neck surgical procedures under general anesthesia were enrolled to quantify the effect of subdermal infiltration of 1% lidocaine with epinephrine at varying concentrations on local cutaneous bloodflow utilizing laser Doppler flowmetry. A comparison of the onset of vasoconstriction and magnitude of diminished bloodflow was made for several commonly used concentrations of epinephrine, with 1% lidocaine and normal saline serving as controls. There were no significant differences (P > .05) between epinephrine concentrations of 1:400,000, 1:200,000, 1:100,000, and 1:50,000 when examining onset and magnitude of vasoconstriction.

Risk factors for complications in clean-contaminated head and neck surgical procedures

BACKGROUND

Contamination of a head and neck surgical wound with oropharyngeal secretions has been shown to dramatically increase the incidence of wound complications. Appropriate perioperative antibiotic prophylaxis has significantly reduced contaminated wound infection rates in several previous reports. The current study examined multiple patient parameters to determine risk factors for all perioperative complications following clean-contaminated head and neck surgical procedures.

METHODS

Retrospective review of medical records from 159 patients who underwent clean-contaminated major head and neck surgical procedures at the University of Washington between 1985 and 1991. More than 30 preoperative and operative parameters were evaluated, and all complications were recorded. The data were examined using a multivariate statistical analysis.

RESULTS

An overall complication rate of 63% included 22% with wound infections (oro/pharyngocutaneous fistula or purulent drainage), 22% with other types of infections, and 51% with noninfectious complications. The overall perioperative mortality rate was 1.2% (two patients). Prior radiotherapy, operative time, perioperative transfusion, and flap reconstruction were all associated with a significantly higher overall complication rate (p < or = 0.05). Only prior radiotherapy therapy correlated with an increase in wound infection rate (p = 0.05).

CONCLUSIONS

Prior radiotherapy significantly increases the risk of perioperative complications and wound infections following clean-contaminated head and neck surgical procedures. Other factors reflecting the complexity of the procedure also influence the overall complication rate.

Predictors of carcinomatous invasion of the mandible

The preoperative assessment of mandibular invasion by oral or oropharyngeal squamous cell carcinoma poses a challenge for the head and neck surgeon. A study of 64 composite resection patients was performed to determine which variables in the patient's history, physical exam, and diagnostic workup had a predictive association with carcinomatous mandibular invasion. Four postoperative variables were included in this analysis. Thirty-nine percent of the mandibular specimens demonstrated cancerous involvement. A multivariate recursive partitioning statistical analysis was performed to create a decision tree. Branching was based on the two statistically predictive variables: computed tomographic (CT) scan results and primary tumor location. The guide provides improved predictive accuracy with a 100% negative predictive value (NPV) and a 46% positive predictive value (PPV). This decision guide should help the surgeon provide accurate patient counseling, anticipate reconstructive needs, and maximize surgical oncologic effectiveness.

Orbital decompression for preservation of vision in Graves' ophthalmopathy

Graves' ophthalmopathy (thyroid eye disease) can result in progressive visual loss. The University of Washington (Seattle) experience in orbital decompression was reviewed for the years 1983 through 1990 to determine overall safety and outcome. Twenty patients underwent transantral decompression of 36 orbits for either steroid therapy failure, steroid therapy intolerance, or recurrence of optic neuropathy with tapering of the steroid therapy. Decompression successfully improved visual function in 33 of the orbits (92%) and a second decompression procedure was successful in another two (5%) of the orbits (6%). There were no major complications or cases of decreased visual function. Diplopia, present preoperatively in 17 patients (85%), was improved in eight patients (47%) and unchanged in nine patients (53%). However, of the three patients without preoperative diplopia (15%), one had development of new-onset diplopia postoperatively. Transantral decompression of the orbit offers a safe and effective therapeutic modality for vision-threatening Graves' ophthalmopathy.

Anatomical correlates of functional recovery in the avian inner ear following aminoglycoside ototoxicity

Tucci and Rubel have demonstrated functional recovery of the chick cochlea following aminoglycoside ototoxicity. The cochleae of these same animals were examined by scanning electron microscopy (SEM) in order to further understand this recovery process. Hatchling chicks were given daily doses of gentamicin for 10 days. Auditory-evoked potential measurements and examination of the cochlea by scanning electron microscopy were performed after survival periods of 5 days to 20 weeks. After 5 days of gentamicin exposure, there was near complete basal hair cell loss associated with a high-frequency hearing loss. Apical progression of damage with a broad-band hearing loss occurred over 4 weeks. At 20-weeks, hair cell counts were normal with a small high-frequency hearing loss. Hair cell regeneration played a major role in the functional recovery of the cochlea.

Ventricular function in the single ventricle before and after Fontan surgery

To better delineate the importance of ventricular function in patients with a single ventricle and assess its relation to outcome after the Fontan procedure, 47 patients with a single ventricle were studied. Ventricular ejection fraction was estimated by radionuclide angiocardiography. Before Fontan surgery, ejection fraction was 0.57 +/- 0.10 (mean +/- standard deviation). This differed significantly from the normal mean left ventricular ejection fraction of 0.68 +/- 0.09 (p less than 0.001) derived in our laboratory by radionuclide angiocardiographic methods. Age, ventricular morphology and the presence of pulmonary artery band or systemic to pulmonary artery shunts had no statistical relation to ventricular ejection fraction in patients with a single ventricle. Serial preoperative evaluation in 15 patients over 3.8 +/- 1.3 years revealed no significant change in ventricular ejection fraction; however, increased atrioventricular valve regurgitation was documented in 4 of these 15. Modified Fontan procedure was performed in 24 of the 47 study patients; 7 have died, 1 has undergone cardiac transplantation and 1 faces possible transplantation. No difference was noted in preoperative ejection fraction between survivors and nonsurvivors. Ventricular morphology, age at Fontan surgery and operative factors such as bypass and cross-clamp time were not related to functional outcome. Preoperative ejection fraction of 0.52 +/- 0.08 decreased to 0.39 +/- 0.11 (p less than 0.001) when evaluated 1.16 +/- 0.44 years after Fontan surgery. In patients with a single ventricle (1) ventricular ejection fraction is less than that of the normal systemic ventricle; (2) during childhood, ejection fraction is not related to age or ventricular morphology; and (3) ventricular ejection fraction frequently decreases after a Fontan repair.(ABSTRACT TRUNCATED AT 250 WORDS)

Hair cell regeneration in the avian cochlea: if it works in birds, why not in man?

Hearing loss caused by cochlear hair cell loss is the most common process afflicting the hearing impaired. Recent studies in the avian cochlea following ototoxic drug and noise damage have demonstrated a remarkable capacity for anatomical and functional recovery. Hair cell regeneration has been shown to play a major role in this recovery process. Future studies may one day make hair cell regeneration or transplantation possible in man.

Preoperative and postoperative "aneurysm" associated with coarctation of the aorta

The reported incidence of aortic aneurysm after surgical repair or balloon angioplasty for aortic coarctation varies widely. To determine the incidence of aneurysm formation after surgery, preoperative and postoperative cineangiograms from 65 patients who underwent operation at age 1.5 +/- 3.4 years were examined. Repair included a prosthetic patch in 14 patients, end to end anastomosis in 28 and subclavian flap in 23. Aneurysm was documented by change in contour or irregularities in contour at the repair site or by abnormal dimensions at the repair site, defined by the ratio of the widest measurement at the repair site to the measurement of the aorta at the diaphragm. An aneurysmal bulge above the ductus diverticulum was identified in 14 (23%) of 60 patients preoperatively; the area showed no change 4.72 +/- 4.07 years after surgery. Significant changes at the repair site were seen in only three patients, all of whom had Dacron patch repair. One patient had a change in contour at the repair site, one had an abnormally high repair site to diaphragmatic aorta ratio and one had a progressive increase in this ratio. Thus, during childhood years, 3 (5%) of 65 patients were diagnosed as having aneurysm at the surgical repair site. In conclusion, 1) comparison with preoperative cineangiograms, especially for aneurysmal bulges above the ductus arteriosus, is essential before an aneurysm can be attributed to coarctation repair by any technique, and 2) aneurysm developed only in patients subjected to Dacron patch repair.

Cor triatriatum: clinical presentation and surgical results in 12 patients

Twelve patients with cor triatriatum have been seen at our institution since 1979. The clinical presentation, diagnostic evaluation, and surgical results are outlined in this retrospective review. Operation is the treatment of choice for this rare congenital cardiac defect. One patient died 1 day before scheduled operation, and 2 patients died postoperatively, yielding a surgical mortality rate of 17% and an overall mortality rate of 25%. Resection of the obstructing atrial membrane was performed using hypothermic cardiopulmonary bypass in all cases. Left atriotomy was performed in 6 patients, and right atriotomy was performed in 7. The two postoperative deaths occurred in patients who had serious associated cardiac defects. Associated anomalies include atrial septal defect, persistent left superior vena cava, and partial anomalous pulmonary venous return. The postoperative course has been excellent in all 9 surviving patients; all remain asymptomatic. Cor triatriatum is amenable to surgical repair with excellent results when diagnosed early and when not complicated by other severe cardiac anomalies.

Assessment of ventricular function in infants and children. Response to dobutamine infusion

A method to assess ventricular functional reserve in infants and children unable to perform dynamic exercise was evaluated. Left ventricular ejection fraction was measured by radionuclide angiocardiography at rest and during infusion of dobutamine in 5-15 micrograms/kg/min dosages. The only side effects noted were arrhythmias in two patients, who had similar ectopy documented previously. Group left ventricular ejection fraction increased from 0.40 +/- 0.21 to a maximum of 0.49 +/- 0.24 (P less than 0.001). Left ventricular ejection fraction at 5 micrograms/kg/min (0.44 +/- 0.23) was not statistically different from that measured during infusion of dobutamine at 10 micrograms/kg/min (0.48 +/- 0.24). The six patients receiving anthracyclines, who had relatively low function at rest and increased function during dobutamine administration, were continued on their anticancer regimen without deteriorating in condition. Absolute values of left ventricular ejection fraction correlated best with the prognosis in patients with idiopathic dilated cardiomyopathy or structural abnormalities; six out of ten patients whose left ventricular ejection fraction never rose above 0.40 have either died or are in transplant protocols. Thus, study of left ventricular function can be performed easily during dobutamine infusion, generating valuable prognostic information.

Balloon pulmonary valvuloplasty: results of the Valvuloplasty and Angioplasty of Congenital Anomalies Registry

Eight hundred twenty-two balloon pulmonary valvuloplasties were reported to the Valvuloplasty and Angioplasty of Congenital Anomalies Registry. Before and after systolic outflow gradients were recorded in 784 valvuloplasties, and the gradient decreased from 71 +/- 33 to 28 +/- 21 mm Hg. The sites of residual obstructions could be ascertained in 196 patients. In these, the total systolic outflow gradients decreased from 85 +/- 41 mm Hg to 33 +/- 27 mm Hg. Of this total residual gradient, 16 +/- 15 mm Hg was transvalvar and 18 +/- 24 mm Hg was infundibular. The degree to which infundibular obstruction subsequently resolved was not determined in this study. The procedure was less effective in reducing outflow gradients in patients with dysplastic valves with or without Noonan's syndrome. There were 5 major complications (0.6%), including 2 deaths (0.2%), a cardiac perforation with tamponade (0.1%) and 2 tricuspid insufficiencies (0.2%). There were 11 minor complications (1.3%) and 21 incidents (2.6%). The incidence of major complications, minor complications and incidents was inversely related to age; it was substantially higher in infants and, in particular, neonates. Balloon pulmonary valvuloplasty is a safe and effective method of lowering pulmonary outflow gradients in infants, children and adults. Small transvalvar and varied infundibular gradients commonly are present at the end of the procedure. Assessing the full effect of the procedure requires intermediate-term follow-up and assessing the duration of relief requires long-term follow-up.