- Pediatric Surgery
- Thyroid Surgery
- Laparoscopic and Thoracoscopic Surgery
Clinical Professor, Surgery - Pediatric Surgery
Surgical Director of Procedural and Diagnostic Services, Lucille Packard Children's Hospital (2016 - Present)
Associate Vice President of Medical Affairs, Lucile Packard Children's Hospital (2011 - Present)
Division Chief, Pediatric Surgery, Stanford University School of Medicine (2012 - 2016)
Honors & Awards
President, Association of Pediatric Surgery Program Directors (2003-2006)
President-Elect Medical Staff, Children's National Medical Center, Washington, D.C. (2004)
Vice-President Medical Staff, Lucile Packard Children's Hospital (2006 -7)
Best Doctors in America, Best Doctors Inc. (2005, 2006, 2007, 2011)
Guide to America's Top Surgeons, Consumer's Research Council of America (2007)
President- Medical Staff, Lucile Packard Children's Hospital (2007-2010)
Fellowship: Stanford University Pediatric Surgery (1981) CA
Residency: Alameda County Medical Center UCSF East Bay Surgical Residency (1979) CA
Internship: Alameda County Medical Center UCSF East Bay Surgical Residency (1975) CA
Board Certification: American Board of Surgery, Surgical Critical Care (1991)
Board Certification: American Board of Surgery, Pediatric Surgery (1984)
Residency: University of Oklahoma (1983) OK
Board Certification: American Board of Surgery, General Surgery (1980)
Medical Education: University of Wisconsin Medical School (1974) WI
BA, University of Wisconsin, Psychology (1970)
MD, University of Wisconsin, Medicine (1974)
MBA, The George Washington University, Information Technology (2000)
Current Research and Scholarly Interests
Minimal Access and Robotic Surgery
Optimizing Professional Practice Evaluation to Enable a Nonpunitive Learning Health System Approach to Peer Review.
Pediatric quality & safety
2021; 6 (1): e375
Healthcare organizations are focused on 2 different and sometimes conflicting tasks; (1) accelerate the improvement of clinical care delivery and (2) collect provider-specific data to determine the competency of providers. We describe creating a process to meet both of these aims while maintaining a culture that fosters improvement and teamwork.Methods: We created a new process to sequester activities related to learning and improvement from those focused on individual provider performance. We describe this process, including data on the number and type of cases reviewed and survey results of the participant's perception of the new process.Results: In the new model, professional practice evaluation committees evaluate events purely to identify system issues and human factors related to medical decision-making, resulting in actional improvements. There are separate and sequestered processes that evaluate concerns around an individual provider's clinical competence or behavior. During the first 5 years of this process, 207 of 217 activities (99.5%) related to system issues rather than issues concerning individual provider competence or behavior. Participants perceived the new process as focused on identifying system errors (4.3/5), nonpunitive (4.2/5), an improvement (4.0/5), and helped with engagement in our system and contributed to wellness (4.0/5).Conclusion: We believe this sequestered approach has enabled us to achieve both the oversight mandates to ensure provider competence while enabling a learning health systems approach to build the cultural aspects of trust and teamwork that are essential to driving continuous improvement in our system of care.
View details for DOI 10.1097/pq9.0000000000000375
View details for PubMedID 33409427
Transfusion Management of Conjoined Twins Undergoing Surgical Separation: A Single Center Experience with Three Sets of Thoraco-Omphalopagus Twins over Ten Years
WILEY. 2018: 122A–123A
View details for Web of Science ID 000444475900280
- Salvage of a failed open gastrocutaneous fistula repair with an endoscopic over-the-scope clip JOURNAL OF PEDIATRIC SURGERY CASE REPORTS 2016; 8: 40–41
Severe lactic acidosis and multiorgan failure due to thiamine deficiency during total parenteral nutrition.
BMJ case reports
A 16-year-old perioperative paediatric patient presented with refractory lactic acidosis and multiorgan failure due to thiamine-deficient total parenteral nutrition during a recent national multivitamin shortage. Urgent empiric administration of intravenous thiamine resulted in prompt recovery from this life-threatening condition. Despite readily available treatment, a high index of suspicion is required to prevent cardiovascular collapse and mortality.
View details for DOI 10.1136/bcr-2014-205264
View details for PubMedID 24895398
- Conjoined Twins FUNDAMENTALS OF PEDIATRIC SURGERY 2011: 893–99
Outcomes of sutureless gastroschisis closure
JOURNAL OF PEDIATRIC SURGERY
2009; 44 (10): 1947-1951
A new technique of gastroschisis closure in which the defect is covered with sterile dressings and allowed to granulate without suture repair was first described in 2004. Little is known about the outcomes of this technique. This study evaluated short-term outcomes from the largest series of sutureless gastroschisis closures.A retrospective case control study of 26 patients undergoing sutureless closure between 2006 and 2008 was compared to a historical control group of 20 patients with suture closure of the abdominal fascia between 2004 and 2006. Four major outcomes were assessed: (1) time spent on ventilator, (2) time to initiating enteral feeds, (3) time to discharge from the neonatal intensive care unit, and (4) rate of complications.In multivariate analysis, sutureless closure of gastroschisis defects independently reduced the time to extubation as compared to traditional closure (5.0 vs 12.1 days, P = .025). There was no difference in time to full enteral feeds (16.8 vs 21.4 days, P = .15) or time to discharge (34.8 vs 49.7 days, P = .22) with sutureless closure. The need for silo reduction independently increased the time to extubation (odds ratio, 4.2; P = .002) and time to enteral feeds (odds ratio, 5.2; P < .001). Small umbilical hernias were seen in all patients.Sutureless closure of uncomplicated gastroschisis is a safe technique that reduces length of intubation and does not significantly alter the time required to reach full enteral feeds or hospital discharge.
View details for DOI 10.1016/j.jpedsurg.2009.03.027
View details for Web of Science ID 000271331700014
View details for PubMedID 19853753
Hemopericardium from coronary artery laceration complicating extracorporeal membrane oxygenation.
Journal of perinatology
1997; 17 (3): 189-192
We report the clinical course and successful surgical treatment of hemopericardium resulting from coronary artery (CA) laceration in two patients with congenital diaphragmatic hernia (CDH) undergoing extracorporeal membrane oxygenation (ECMO) bypass.Retrospective case review.Two neonates with CDH had needle aspiration for either pneumothorax or pericardial effusion before initiation of ECMO. While on bypass, progressive hemopericardium led to narrow pulse pressure and decreased venous return that limited bypass flow. Widened cardiac silhouette on chest radiographs suggested hemopericardium; echocardiography was confirmatory in one case. The underlying diagnosis of CA laceration was made during pericardiotomy and treated with surgical patching.Pre-ECMO history of cardiothoracic needle aspiration is important because complications such as hemothorax or hemopericardium may arise once ECMO bypass is initiated. Inadvertent CA laceration may lead to acute hemopericardium, compromising venous drainage. However, CA laceration can be successfully repaired while the patient is on bypass.
View details for PubMedID 9210072
LOBAR LUNG TRANSPLANTATION AS A TREATMENT FOR CONGENITAL DIAPHRAGMATIC-HERNIA
JOURNAL OF PEDIATRIC SURGERY
1994; 29 (12): 1557-1560
The mortality rate for infants severely affected with congenital diaphragmatic hernia (CDH) remains high despite significant advances in surgical and neonatal intensive care including delayed repair and extracorporeal membrane oxygenation (ECMO). Because of the increasingly successful experience with single-lung transplantation in adults; this approach has been suggested as a potential treatment for CDH infants with unsalvageable pulmonary hypoplasia. The authors report on a newborn female infant who was the product of a pregnancy complicated by polyhydramnios. At birth, she was found to have a right-sided CDH and initially was treated with preoperative ECMO, followed by delayed surgical repair. Despite the CDH repair and apparent resolution of pulmonary hypertension, the infant's condition deteriorated gradually after decannulation, and escalating ventilator settings were required as well as neuromuscular paralysis and pressor support because of progressive hypoxemia and hypercarbia. A lung transplant was performed 8 days after decannulation, using the right lung obtained from a 6-week-old donor. The right middle lobe was excised because of the size discrepancy between the donor and recipient. After transplantation, the patient was found to have duodenal stenosis and gastroesophageal reflux, which required duodenoduodenostomy and fundoplication. The patient was discharged from the hospital 90 days posttransplantation, at 3 1/2 months of age. Currently she is 24 months old and doing well except for poor growth. This case shows the feasibility of single-lung transplantation for infants with CDH, and the potential use of ECMO as a temporary bridge to transplantation. Lobar lung transplantation allowed for less stringent size constraints for the donor lung.
View details for Web of Science ID A1994PW61200018
View details for PubMedID 7877027
EARLY HERNIA REPAIR IN THE PREMATURE-INFANT - LONG-TERM FOLLOW-UP
1993 Annual Meeting of the Section on Surgery of the American-Academy-of-Pediatrics
W B SAUNDERS CO. 1994: 978–82
The incidence of inguinal hernia and incarceration is high among premature infants. Optimal timing, anesthetic technique, and long-term results of hernia repair in hospitalized premature infants remain undefined. The authors reviewed the records of 52 consecutively treated premature infants who underwent bilateral inguinal herniorrhaphy under general anesthesia before discharge from the intensive care nursery. There were no significant differences in gestational age, birth weight, age and weight at time of surgery, or presence of preoperative apnea or bradycardia in between infants extubated within 24 hours and those intubated for more than 24 hours. Twenty-four infants (46%) were available for follow-up of 24 months or more (mean follow-up period, 57 months). One recurrence was identified, representing 4% of the long-term follow-up group and 2% of the initial population. Two patients had asymmetric testicular volumes suggestive of unilateral atrophy. The short- and long-term results suggest that repair under general anesthesia can be safely performed before discharge from the intensive care nursery.
View details for Web of Science ID A1994PB51600005
View details for PubMedID 7965533
PERITONEAL DRAINAGE AS PRIMARY MANAGEMENT OF PERFORATED NEC IN THE VERY-LOW-BIRTH-WEIGHT INFANT
24th Annual Meeting of the American-Pediatric-Surgical-Association
W B SAUNDERS CO. 1994: 310–15
Advances in perinatal and neonatal care in the past decade have produced a change in the population of infants with perforated necrotizing enterocolitis (NEC) treated at our institution: the majority are now of very low birth weight (VLBW, < 1,000 g). Peritoneal drainage has been reported as an initial resuscitative procedure for unstable infants who have complicated NEC. Initial success with peritoneal drainage prompted us to adopt an aggressive approach to its use in this patient population. Since 1987, peritoneal drainage has been the primary treatment for most infants weighing less than 1,500 g who have perforation, and for unstable infants weighing more than 1,500 g. Perforation was documented by pneumoperitoneum or aspiration of meconium by paracentesis. Intestinal resection was performed in most infants weighing more than 1,500 g and in those for whom drainage was ineffective. Twenty-nine infants with low or VLBW (mean gestational age, 27 weeks; mean birth weight, 994 g) were treated with one or two drains in the right lower quadrant. Broad spectrum antibiotics were continued until all drains were removed, usually within 10 to 14 days. Nasogastric suction was continued until patency of the gastrointestinal (GI) tract was confirmed by a nonionic upper GI series. Six (21%) infants died, although one of the deaths occurred 5 months after drainage; the patient had chronic lung disease and an intact GI tract. Seventeen of the 23 (74%) survivors required no further operative procedure, and 6 (26%) required laparotomy and resection because drainage had been ineffective. Peritoneal drainage provided definitive treatment in 18 of 29 (62%) infants in this series.(ABSTRACT TRUNCATED AT 250 WORDS)
View details for Web of Science ID A1994MX66700033
View details for PubMedID 8176608
LANGERHANS CELL HISTIOCYTOSIS PRESENTING WITH THE SUPERIOR VENA-CAVA SYNDROME - A CASE-REPORT
MEDICAL AND PEDIATRIC ONCOLOGY
1993; 21 (6): 456-459
A case of Langerhans' cell histiocytosis confined to the mediastinum and presenting with de novo superior cava syndrome is reported. The causes of superior vena cava syndrome in childhood are discussed as is the importance of obtaining pathologic diagnosis prior to initiating therapy.
View details for PubMedID 8515729
ESOPHAGEAL ATRESIA WITH TRIPLE CONGENITAL TRACHEOESOPHAGEAL FISTULAS
JOURNAL OF PEDIATRIC SURGERY
1992; 27 (12): 1527-1528
The surgical management of an infant with esophageal atresia and three (2 proximal and 1 distal) congenital tracheoesophageal fistulae is described. The pitfalls in the diagnosis of proximal fistulae are discussed.
View details for Web of Science ID A1992KC85600016
View details for PubMedID 1469561
SONOGRAPHIC DETECTION OF CONGENITAL PANCREATIC CYSTS IN THE NEWBORN - REPORT OF A CASE AND REVIEW OF THE LITERATURE
1990; 20 (6): 488-490
A case of congenital pancreatic cysts detected antenatally by ultrasound is presented. This is the second case detected antenatally. Congenital pancreatic cysts should be included in the differential diagnosis of upper abdominal cystic masses in the fetus and newborn infant.
View details for Web of Science ID A1990DP57300021
View details for PubMedID 2202976
ABDOMINAL-MASS LESIONS IN THE NEWBORN - DIAGNOSIS AND TREATMENT
CLINICS IN PERINATOLOGY
1989; 16 (1): 123-135
Most neonatal abdominal masses will be due to benign retroperitoneal lesions such as hydronephrosis and multicystic dysplastic kidney. Although history and physical examination, plain radiographs and ultrasonography will confirm most diagnoses, severe unilateral hydronephrosis, hemorrhagic neuroblastoma, and intraperitoneal cysts may provide diagnostic difficulties. Masses identified by prenatal ultrasound need careful evaluation as they may represent normal structures, nonsignificant variants, or physiologically significant anomalies. Many lesions will require operative intervention, which can be safely performed in small infants by trained personnel at facilities with appropriate support services. Genuine controversy exists in the management of some of these lesions including MDK, renal vein thrombosis, and acalculous cholecystitis.
View details for Web of Science ID A1989T887700011
View details for PubMedID 2656056
EXTRA-ADRENAL PHEOCHROMOCYTOMA - AN UNUSUAL LOCATION
JOURNAL OF PEDIATRIC SURGERY
1988; 23 (11): 1045-1047
A 14-year-old boy with a retrohepatic para-aortic pheochromocytoma demonstrates the potential difficulties of localization in an unusual extra-adrenal site of pheochromocytoma. Ultrasonography, computed tomography, metaiodobenzylguanidine scanning, and angiography with venous sampling failed to define the true anatomic location of this tumor. Collateral venous drainage produced confusing venous sampling data and represents a potential pitfall in the interpretation of these studies.
View details for Web of Science ID A1988Q843100025
View details for PubMedID 3244086
POST-NECROTIZING ENTEROCOLITIS STRICTURES PRESENTING WITH SEPSIS OR PERFORATION - RISK OF CLINICAL OBSERVATION
JOURNAL OF PEDIATRIC SURGERY
1988; 23 (6): 562-566
Intestinal stenosis or stricture occurs in approximately one third of medically treated infants surviving the acute phase of necrotizing enterocolitis (NEC). Identification of these lesions by the use of routine contrast enemas has been advocated as a means of decreasing potential morbidity from delayed diagnosis. However, the significant incidence of spontaneous resolution and reluctance to submit asymptomatic infants to contrast enema have led recent researchers to reserve these studies for patients developing symptoms of obstruction during a period of close observation. From July 1984 to July 1986, symptomatic strictures developed in five infants (15%) responding to medical management at our institution. Contrast enemas were not routinely performed and four (80%) of these patients presented with life-threatening sepsis or perforation associated with intestinal obstruction. Two infants developed complete colonic obstruction 4 and 6 weeks after discharge from the Intensive Care Nursery, having initially tolerated oral feedings. Both infants were critically ill due to perforation or sepsis and underwent emergency colostomy at community hospitals. Two other infants developed abdominal distension with sepsis and cardiopulmonary decompensation while remaining hospitalized for prematurity and pulmonary insufficiency. These patients became symptomatic 5 and 7 weeks after cautious refeeding while closely monitored in the Intensive Care Nursery. The occurrence of such life-threatening complications suggests that clinical observation alone is not adequate in the management of many of these infants. Contrast enemas should be performed to identify those patients at risk of such potential morbidity or mortality, especially those infants not residing near pediatric surgical facilities.
View details for Web of Science ID A1988N800300012
View details for PubMedID 3047359
MATURATIONAL PATTERNS OF CARBOHYDRASES IN THE ILEAL REMNANT OF RATS AFTER JEJUNECTOMY AT INFANCY
AMERICAN JOURNAL OF CLINICAL NUTRITION
1988; 47 (5): 868-874
The enteric epithelium of suckling rat undergoes dramatic functional and cytokinetic changes (redifferentiation) with maturation. Ileal epithelial maturation was studied in infant rats subjected to 60% proximal enterectomy at age 10 d in an effort to examine redifferentiation mechanisms. Two months after resection the residual ileal remnant was increased in diameter, weight, total protein, and DNA per unit length compared with ileal segments from control littermates that had laparotomy without resection. The residual ileum demonstrated increased sucrase activity per unit length but was indistinguishable from control ileal segments in activity per unit DNA or villus distribution. Lactase activity was negligible in all segments of the residual intestine. Villus height and crypt depth were increased in the residual ileum with slight increases in cell turnover and cell-migration rates. These results show the presence of an intrinsic program for regulation of ileal epithelial maturation and its resistance to alteration by a major stimulus applied before its expression.
View details for Web of Science ID A1988N242700015
View details for PubMedID 3129930
WATERSEAL GASTROSTOMY IN THE MANAGEMENT OF PREMATURE-INFANTS WITH TRACHEOESOPHAGEAL FISTULA AND PULMONARY-INSUFFICIENCY
JOURNAL OF PEDIATRIC SURGERY
1988; 23 (1): 29-31
The perioperative management of premature infants with esophageal atresia and tracheoesophageal fistula (EA/TEF) complicated by pulmonary insufficiency continues to be a challenge. Definitive repair is usually delayed or staged and a gastrostomy is initially placed to prevent reflux aspiration. In patients with decreased pulmonary compliance, gastrostomy placement results in decreased intragastric pressure leading to a loss of ventilatory pressure via the tracheoesophageal fistula. A technique using the principle of underwater seal to maintain effective ventilatory pressure after gastrostomy placement is described, and two illustrative cases are presented. After acute respiratory decompensation in these patients, the gastrostomy tube was connected to underwater seal resulting in improved respiratory status. The underwater seal is allowed to intermittently "bubble," thereby permitting partial gastric decompression. This technique maintains effective ventilatory pressure after gastrostomy placement in premature infants with EA/TEF and pulmonary insufficiency until definitive therapy can be achieved.
View details for Web of Science ID A1988L764300006
View details for PubMedID 3351723
MANAGEMENT OF SEPTIC COMPLICATIONS ASSOCIATED WITH SILASTIC CATHETERS IN CHILDHOOD MALIGNANCY
PEDIATRIC INFECTIOUS DISEASE JOURNAL
1987; 6 (11): 1042-1047
From January, 1979, to December, 1984, 63 Hickman or Broviac catheters were inserted into 50 high risk pediatric oncology patients (median age, 37 months). Catheters remained in place for an average of 241 days. Possible catheter sepsis and exit site infection accounted for the majority (39 of 76) of the complications of long term central venous catheterization. Neutropenia (absolute neutrophil count under 500/mm3) was associated with 70% of the catheter-related infections and 75% of the non-catheter-related infections. Catheters inserted during neutropenic episodes (23) were associated with an increased risk of subsequent septicemia (60% vs. 25%), a finding apparently related to their exposure to further neutropenia (38% vs. 16% catheter days). Of the 32 episodes of septicemia of unknown origin, 19 involved Gram-negative bacteria, 14 involved Gram-positive bacteria and 4 were caused by fungi. Five of these episodes involved multiple organisms. Staphylococcus epidermidis was the most common Gram-positive organism isolated (7 of 14). Four episodes of septicemia resolved before therapy and are considered false positive cultures. Of the other 28 episodes of septicemia, 25 (89%) were successfully treated without catheter removal including 3 episodes of fungemia and 4 of multiple organism sepsis. These data demonstrate the efficacy of antimicrobial treatment without catheter removal in the pediatric oncology population with catheter-associated infections including those associated with neutropenia, multiple organisms and fungemia.
View details for Web of Science ID A1987K989800009
View details for PubMedID 3696842
THE DILEMMA OF THE MULTICYSTIC DYSPLASTIC KIDNEY
AMERICAN JOURNAL OF DISEASES OF CHILDREN
1986; 140 (9): 925-928
Multicystic dysplastic kidney is the most frequent cause of an abdominal mass in the neonate, but controversy continues as to the optimal management of these lesions, since little is known about their natural history. Experience with two complicated cases and a review of reports of retained multicystic dysplastic kidneys suggest that such lesions pose a significant risk to their hosts. Malignancy, reversible hypertension, pain, and mass effect have been associated with retained lesions. Infection is another potential hazard that is frequently cited but poorly documented in the literature. In light of the currently low morbidity and mortality associated with operation and anesthesia in the neonatal period, resection appears to be the treatment of choice for the neonate with a multicystic dysplastic kidney.
View details for Web of Science ID A1986D779400039
View details for PubMedID 3017096
PRIMARY PULMONARY NEOPLASMS OF CHILDHOOD - A REVIEW
ANNALS OF THORACIC SURGERY
1983; 36 (1): 108-119
Primary tumors of the lung rarely occur in children. However, 230 well-documented cases, including the 2 presented in this review, have been identified in the English-language literature. One hundred fifty-one tumors in these reports were classified as malignant lesions and 79 as benign neoplasms. Bronchial "adenomas" constituted the largest group; most of these lesions were of the carcinoid variety, and 8% were definitely malignant. Forty-seven cases of bronchogenic carcinoma were reported in children under 16 years of age, although there were few squamous cell tumors (12%). Fifty-six percent of the benign tumors were classified as inflammatory pseudotumor. Most of the children in this collective series were seen with symptoms related to bronchial irritation or obstruction, such as cough, hemoptysis, atelectasis, or pneumonitis. Respiratory distress was an unusual symptom that was often associated with large tumors seen in the neonatal period. Approximately 20% of the children were totally symptomatic. The limited survival data that are available indicate that leiomyosarcoma and mucoepidermoid carcinoma have a more favorable prognosis in children than in adults. Survival with bronchial carcinoid tumors (90%), bronchogenic carcinoma (30%), and pulmonary blastoma (45%) appears to parallel that for adults. The experience with pulmonary rhabdomyosarcoma, as described in this review, emphasizes the importance of early diagnosis and the use of combined modes of therapy in the approach to these malignancies. Despite the rarity of primary pulmonary neoplasms in children, this diagnosis should be considered in young patients with solitary pulmonary masses or persistent, atypical pulmonary symptoms. It is hoped that early diagnosis will result in an improved prognosis and prevent life-threatening complications.
View details for Web of Science ID A1983QX79600021
View details for PubMedID 6344822
MOIRE PHOTOTOPOGRAPHY IN THE EVALUATION OF ANTERIOR CHEST WALL DEFORMITIES
JOURNAL OF PEDIATRIC SURGERY
1981; 16 (3): 353-357
One of the major remaining problems in the management of children with anterior chest wall deformities is the lack of a widely accepted objective method of evaluating the severity of the deformity. This deficiency has made it difficult to evaluate indications for operation or the results of operative repair. Moiré phototopography is a new method of accurately measuring human body contours utilizing recent developments in applied optics and has been used successfully in scoliosis screening programs. This technique has been applied to the evaluation of anterior chest wall deformities and the initial results of this study are presented. Moiré phototopography has proven to be a sensitive, reproducible, and easy to perform method of quantitating pectus deformities. While further evaluation is required, this early experience suggests this technique may provide a means of accurately and objectively measuring chest wall deformities so that their physiologic significance can be precisely investigated and the results of therapy critically reviewed.
View details for Web of Science ID A1981LS41400026
View details for PubMedID 7252740