Per Oral Endoscopic Myotomy (POEM) for pediatric achalasia: Institutional experience and outcomes.

BACKGROUND: The surgical treatment of achalasia by both laparoscopic and endoscopic approaches has been recognized as the definitive management in children. Despite reported low volumes in many centers, there has been an increasing worldwide experience with endoscopic approaches to pediatric achalasia. The aim of this study is to report our institutional experience with per oral endoscopic myotomy (POEM) as first-line or revisional therapy for achalasia. METHODS: An IRB approved retrospective review of all patients who underwent operative procedures for achalasia, specifically with the POEM technique, from July 2015 to September 2021. Data including demographics, intra-operative details, pre and post operative Eckardt scores, complications, outcomes, and follow-up were obtained. RESULTS: During the study period, a total of 43 children underwent 46 operations for achalasia including POEM and laparoscopic Heller myotomy (LHM). Operations included 37 POEMS (33 primary POEMS; 3 POEMS after failed LHM; and 1 POEM after failed POEM). Additionally, 9 LHM operations including, 4 primary LHM; 3 attempted POEMS converted to LHM; 1 attempted POEM after failed LHM converted to redo LHM; and 1 LHM after failed POEM. In the POEM group (n = 37), based on the high resolution esophageal manometry findings Chicago Classification types at diagnosis were as follows: 9 patients were type I (24.3%); 25 patients were type II (67.6%); 2 patients were type III (5.9%) and 1 patient was unknown type (2.7%). Sixteen children (43.2%) had prior endoscopic treatment of achalasia prior to POEM [Pneumatic Balloon Dilatation (PBD), and/or Botox injection (BTI)],), while prior operative intervention occurred in 4 patients (10.8%), 3 LHM and 1 POEM. Age at operation was 2-18 years (mean ± SD age: 11.6 ± 4.5 years). Weight at operation 11.8-100.7 kg (mean ± SD kg; 39 ± 19.9 kg). Range of baseline Eckardt score was 4-10 (mean ± SD: 6.73 ± 1.5). Operative time was 64-359 min (mean ± SD minutes: 138.1 ± 62.2 min). Intraoperative complications occurred in 16 patients (43.2%) but did not require reoperation during index admission including: 4 mucosotomy (11.8%); 9 pneumothoraces (24.3%); 2 pneumomediastinum (5.4%); 10 pneumoperitoneum (27%); 0 sub-mucosal tunnel bleeding (0%); 0 open conversion/death (0%). Post operative complications included: 5 recurrent dysphagia (13.5%); 0 esophageal leak (0%); 3 GERD (8.1%); 1 failed POEM (2.7%). Median length of stay was 2 days (mean ± SD days: 2.4 ± 0.9 day). Follow-up ranged from 1 to 74 months (median 15 months), mean follow-up 22.6 months ± 20 months. Post POEM Eckardt score was 0.6 ± 0.9. Five patients required a single PBD post POEM (13.5%) and 1 patient required a repeat myotomy (LHM) after POEM (2.7%) for a 16.2% reintervention rate. Subsequent normalization of Eckardt scores (≤ 3) and symptomatic relief was achieved in all patients (100%). CONCLUSIONS: POEM as first-line therapy for pediatric achalasia, or as a secondary procedure after failed prior myotomy or POEM, in our experience is safe and effective. We have shown equivalent results to our own prior experience with LHM. Long-term follow-up will be performed to monitor for recurrent symptoms, adequate physical growth, and general development. LEVEL OF EVIDENCE: II.

Current management of pediatric achalasia.

Achalasia is a rare condition affecting esophageal motility in children. In a manner similar to the disease found in the adult population, children experience symptoms of dysphagia, regurgitation, and chest pain due to a failure of relaxation of the lower esophageal sphincter. Standard diagnostic approaches include upper endoscopy and esophageal manometry. New developments in diagnosis include high-resolution esophageal manometry and the endoscopic functional lumen imaging probe. Therapies available include endoscopic balloon dilations and botulinum toxin injections into the lower esophageal sphincter, as well as surgical interventions. The Heller myotomy was first described in 1913; since then, there have been many modifications to the procedure to improve outcomes and lower morbidity. Currently, the most commonly performed surgical procedure is the laparoscopic Heller myotomy, in which the sphincter muscle is divided using longitudinal incisions with or without a partial fundoplication procedure. In recent years, per oral endoscopic myotomy (POEM) is gaining support as a viable natural orifice therapy for achalasia. Complications of POEM occur at a relatively low rate, and outcomes following the procedure have been promising. The treatment of end-stage achalasia however, may include partial or total esophagectomy with reconstruction if possible. Future research is focused primarily on increasing the efficacy, and lowering complications, of existing therapeutic modalities.

Case series of metal allergy following Nuss procedure: Not only for stainless steel bars.

BACKGROUND: Pectus excavatum is often managed with the Nuss procedure. Metal allergies to pectus bars occur in 5% of patients, though pre-operative testing is not generally routine. OBJECTIVES: This study describes our experience with pre-operative metal allergy testing and post-operative allergic reactions to pectus bars. METHODS: A retrospective study of patients who underwent a Nuss procedure at our institution from 2010-2020 was performed. Patients with documented "metal" allergy, defined by the need for and positive response to steroid treatment and the absence of infection, were included. Data on patient characteristics and clinical course were analyzed. RESULTS: Five of 204 patients (2.5%) identified developed allergic metal reactions. Three of five patients developed allergic reactions to titanium bars, with two requiring early removal of the bar (< 2-3 years). Four patients required more than one course of steroids, and three required debridements for skin breakdown. All patients have maintained good surgical correction at one- and three-years post removal. CONCLUSIONS: Pectus bar metal allergies occur with both stainless steel and titanium bars. Properly selected patients for pre-operative FinnⓇ Chamber testing may reduce the overall incidence of stainless-steel allergies but may miss titanium bar allergies. Early recognition and treatment of bar allergies may salvage the bar and avoid premature removal.

Median Arcuate Ligament Syndrome with Orthostatic Intolerance: Intermediate-Term Outcomes following Surgical Intervention.

OBJECTIVES: To report the intermediate-term outcome following surgical intervention for median arcuate ligament syndrome (MALS) in adolescents and young adults with orthostatic intolerance (OI) to assess clinical improvement in the gastrointestinal and 5 other functional domains and if relief of arterial obstruction is associated with resolution of clinical symptoms. STUDY DESIGN: Thirty-one patients were given 2 dysautonomia-designed questionnaires to assess changes in symptoms following operative intervention in 6 functional domains and underwent postoperative repeat abdominal ultrasound examinations. RESULTS: Average follow-up after surgery was 22.4 ± 14.8 months. Self-assessed quality of health on a Likert scale (1-10 with 10 being normal) improved from 4.5 ± 2.1 preoperatively to 5.3 ± 2.4 postoperatively (P = not significant). Gastrointestinal symptoms of abdominal pain, nausea, and vomiting improved in 63% (P = .007), 53% (P = .040), and 62% (P = .014) of patients, respectively. Cardiovascular symptoms of dizziness, syncope, chest pain, and palpitations improved in 45% (P = not significant), 50% (P = not significant), 54% (P = .043), and 54% (P = .037) of patients, respectively. Transabdominal ultrasound peak supine expiratory velocity decreased from 348 ± 105 cm/s preoperatively to 251 ± 109 cm/s at 6 months or more after a ligament release procedure. Decrease of the postoperative celiac artery Doppler velocity was not associated with an improvement in gastrointestinal symptoms (P = .075). CONCLUSIONS: Adolescent and young adult patients with median arcuate ligament syndrome and OI have a good response to surgical intervention. About two-thirds of patients report significant improvement in symptoms of abdominal pain, nausea, and vomiting. Despite these encouraging data, many patients with MALS and OI continue to have an impaired quality of health.

Preclinical evaluation of ultrasound-augmented needle navigation for laparoscopic liver ablation.

PURPOSE: For laparoscopic ablation to be successful, accurate placement of the needle to the tumor is essential. Laparoscopic ultrasound is an essential tool to guide needle placement, but the ultrasound image is generally presented separately from the laparoscopic image. We aim to evaluate an augmented reality (AR) system which combines laparoscopic ultrasound image, laparoscope video, and the needle trajectory in a unified view. METHODS: We created a tissue phantom made of gelatin. Artificial tumors represented by plastic spheres were secured in the gelatin at various depths. The top point of the sphere surface was our target, and its 3D coordinates were known. The participants were invited to perform needle placement with and without AR guidance. Once the participant reported that the needle tip had reached the target, the needle tip location was recorded and compared to the ground truth location of the target, and the difference was the target localization error (TLE). The time of the needle placement was also recorded. We further tested the technical feasibility of the AR system in vivo on a 40-kg swine. RESULTS: The AR guidance system was evaluated by two experienced surgeons and two surgical fellows. The users performed needle placement on a total of 26 targets, 13 with AR and 13 without (i.e., the conventional approach). The average TLE for the conventional and the AR approaches was 14.9 mm and 11.1 mm, respectively. The average needle placement time needed for the conventional and AR approaches was 59.4 s and 22.9 s, respectively. For the animal study, ultrasound image and needle trajectory were successfully fused with the laparoscopic video in real time and presented on a single screen for the surgeons. CONCLUSION: By providing projected needle trajectory, we believe our AR system can assist the surgeon with more efficient and precise needle placement.

Evidence of GMPPA founder mutation in indigenous Guatemalan population associated with alacrima, achalasia, and mental retardation syndrome.

Congenital disorders of glycosylation (CDG) are a heterogeneous group of inborn errors of metabolism mostly causing multisystem disease. In 2013, biallelic mutations in the GMPPA gene were described in association with one such CDG known as alacrima, achalasia, and mental retardation syndrome (AAMR). To date, 18 patients have been reported, nearly all displaying the same pathognomonic triad of symptoms described in the name. This condition shares considerable phenotypic overlap with Triple-A syndrome caused by biallelic mutations in the AAAS gene; however, AAMR lacks the characteristic adrenocortical findings associated with Triple-A syndrome. We report three patients from two unrelated families with the same homozygous GMPPA mutation (c.265dup, p.L89fs). Notably, both families reported indigenous Maya-Mam heritage and originated from the town of Concepción Chiquirichapa in Quezaltenango, Guatemala. Our cases help to expand the AAMR phenotype by outlining dysmorphic features not well described in the prior cases. Additionally, we encourage all providers with patients presenting with this unique triad of symptoms to consider sequencing of the GMPPA gene. Special consideration should be given to families of Guatemalan Maya-Mam ancestry who may also have this identified founder mutation. Finally, this condition may indeed be underdiagnosed based on a review of the literature.

GPS Laparoscopic Ultrasound: Embedding an Electromagnetic Sensor in a Laparoscopic Ultrasound Transducer.

Tracking the location and orientation of a laparoscopic ultrasound (LUS) transducer is a prerequisite in many surgical visualization and navigation applications. Electromagnetic (EM) tracking is a preferred method to track an LUS transducer with an articulating imaging tip. The conventional approach to integrating EM tracking with LUS is to attach an EM sensor on the outer surface of the imaging tip (external setup), which is not ideal for routine clinical use. In this work, we embedded an EM sensor inside a standard LUS transducer. We found that ultrasound image quality and the four-way articulation function of the transducer were not affected by this sensor integration. Furthermore, we found that the tracking accuracy of our integrated transducer was comparable to that of the external setup. An animal study conducted using the developed transducer suggests that an internally embedded EM sensor is a clinically more viable approach, and may be the future of tracking an articulating LUS transducer.

Laparoscopic Liver Resection with Augmented Reality: A Preclinical Experience.

INTRODUCTION: Intraoperative imaging, such as ultrasound, provides subsurface anatomical information not seen by standard laparoscopy. Currently, information from the two modalities may only be integrated in the surgeon's mind, an often distracting and inefficient task. The desire to improve intraoperative efficiency has guided the development of a novel, augmented reality (AR) laparoscopic system that integrates, in real time, laparoscopic ultrasound (LUS) images with the laparoscopic video. This study shows the initial application of this system for laparoscopic hepatic wedge resection in a porcine model. MATERIALS AND METHODS: The AR system consists of a standard laparoscopy setup, LUS scanner, electromagnetic tracking system, and a laptop computer for image fusion. Two liver lesions created in a 40-kg swine by radiofrequency ablation (RFA) were resected using the novel AR system and under standard laparoscopy. RESULTS: Anatomical details from the LUS were successfully fused with the laparoscopic video in real time and presented on a single screen for the surgeons. The RFA lesions created were 2.5 and 1 cm in diameter. The 2.5 cm lesion was resected under AR guidance, taking about 7 minutes until completion, while the 1 cm lesion required 3 minutes using standard laparoscopy and ultrasound. Resection margins of both lesions grossly showed noncoagulated liver parenchyma, indicating a negative-margin resection. CONCLUSIONS: The use of our AR system in laparoscopic hepatic wedge resection in a swine provided real-time integration of ultrasound image with standard laparoscopy. With more experience and testing, this system can be used for other laparoscopic procedures.

Congenital paraesophageal hernia: Contemporary results and outcomes of laparoscopic approach to repair in symptomatic infants and children.

BACKGROUND: Congenital paraesophageal hernia (CPEH) is a rare diaphragmatic anomaly for which repair has primarily been described by laparotomy, although, more recent case series describe laparoscopic repair. In reports with over five patients, the predominant approach has been with laparotomy. The purpose of our study was to review our recent institutional experience and results with exclusively laparoscopic repair of CPEH in infants and children. METHODS: An IRB approved retrospective review of all patients with CPEH who underwent laparoscopic treatment at a tertiary children's hospital from 2010 to 2017 was performed. We included only those patients from our own institution with primary CPEH, or CPEH with prior repair (s) at other centers, with recurrence presenting for operation. Data including demographics, diagnostic studies, operative details, complications, outcomes, and follow up were analyzed. Age at diagnosis was 1 day to 25 years of age (mean 2.5 years). RESULTS: A total 28 patients underwent 30 operations to treat CPEH. All operations were completed laparoscopically with no conversions to open. There were 6 Type II, 16 Type III, and 6 Type IV CPEH patients. Seventeen patients were less than one year of age (61%). Weight at time of repair was 10.3 kg (1.2-44 kg). Twelve patients were less than 5 kg (43%), eight patients (28.5%) were less than 10 kg, and 8 were more than 10 kg (28.5%). Operative time averaged 125 min (range 61-247 min). Three patients underwent initial CPEH repair (s) (open: 2 and laparoscopic: 1) at other institutions before laparoscopic revision was performed at our hospital (11%). Crural repair was performed in all patients, fundoplication in 26 (93%) and concomitant gastrostomy was performed in 14 patients (50%). Complications included two patients with recurrent hiatal hernias, which were redone laparoscopically (2/28 or 7% recurrence) and 1 capnothorax requiring pigtail drainage postoperatively. There were no deaths, no requirement for esophageal dilations, or esophageal lengthening. One patient required laparoscopic gastrostomy six weeks post initial repair for failure to thrive. Follow-up ranged from 4 months to 8 years (average 36 months). CONCLUSION: Congenital paraesophageal hernia in infants and children is uncommon. Based on our experience, the laparoscopic approach to repair is feasible, even for neonates, with excellent results, acceptably low recurrence rate, and may even be considered for revisional operations. STUDY TYPE: Clinical research paper. LEVEL OF EVIDENCE: Type IV.

Lateral Pancreaticojejunostomy for Chronic Pancreatitis and Pancreatic Ductal Dilation in Children.

BACKGROUND: Pancreatic ductal obstruction leading to ductal dilation and recurrent pancreatitis is uncommon in children. Treatment is dependent upon etiology but consists of decompression of the pancreatic duct (PD) proximally, if possible, by endoscopic retrograde cholangiopancreatography (ERCP) intervention or surgical decompression with pancreaticojejunal anastomosis. METHODS: After institutional review board approval, we retrospectively reviewed the records for 2 children who underwent lateral pancreaticojejunostomy for pancreatic ductal dilation. Data, including demographics, diagnostic studies, operative details, complications, outcomes, and follow-up, were analyzed. RESULTS: Case 1 was a 4-year-old female with pancreatic ductal obstruction with multiple episodes of recurrent pancreatitis and failure of ERCP to clear her PD of stones. She underwent a laparoscopic cholecystectomy with a lateral pancreaticojejunostomy (Puestow procedure). She recovered well with no further episodes of pancreatitis and normal pancreatic function 4 years later. Case 2 was a 2-year-old female who developed recurrent pancreatitis and was found to have papillary stenosis and long common bile-PD channel. Despite multiple sphincterotomies, laparoscopic cholecystectomy, and laparoscopic hepaticoduodenostomy, she continued to experience episodes of pancreatitis. She underwent a laparoscopy converted to open lateral pancreaticojejunostomy. Her recovery was also smooth having had no episodes of pancreatitis or hospital admissions for over 2 years following the Puestow. CONCLUSIONS: Indication for lateral pancreaticojejunostomy or Puestow procedure is rare in children and even less often performed using laparoscopy. In our small experience, both patients with pancreatic ductal obstruction managed with Puestow's procedure enjoy durable symptom and pain relief in the long term.

Splenic myoid angioendothelioma mimicking metastatic disease in an 8-year-old with Stage IV Wilms' tumour.

Myoid angioendothelioma are rare and benign vascular tumours of the spleen. Radiographic evaluation and diagnosis is often challenging and subjecting tissue samples to immuhistochemical analysis is often required to make a definitive diagnosis. Myoidangioendotheliomas can be managed with open or laparoscopic splenectomy with minimal risk of recurrent disease. Herein, we present a case of a myoid angioendothelioma in a patient with stage IV Wilms' tumour.

Primary Omental Torsion in a Pediatric Patient: Case Report and Review of the Literature.

Primary omental torsion is a rare cause of acute abdominal pain with a clinical presentation resembling acute appendicitis. Here, we report the case of a 7-year-old child presenting with right lower quadrant pain. Primary omental torsion was discovered upon laparoscopy, and the torsed omentum was excised without postoperative complications. Potential causes, contributing factors, diagnosis, and treatment are discussed.

Congenital H-type tracheoesophageal fistula: A multicenter review of outcomes in a rare disease.

OBJECTIVE: To perform a multicenter review of outcomes in patients with H-type tracheoesophageal fistula (TEF) in order to better understand the incidence and causes of post-operative complications. BACKGROUND: H-type TEF without esophageal atresia (EA) is a rare anomaly with a fundamentally different management algorithm than the more common types of EA/TEF. Outcomes after surgical treatment of H-type TEF are largely unknown, but many authoritative textbooks describe a high incidence of respiratory complications. METHODS: A multicenter retrospective review of all H-type TEF patients treated at 14 tertiary children's hospital from 2002-2012 was performed. Data were systematically collected concerning associated anomalies, operative techniques, hospital course, and short and long-term outcomes. Descriptive analyses were performed. RESULTS: We identified 102 patients (median 9.5 per center, range 1-16) with H-type TEF. The overall survival was 97%. Most patients were repaired via the cervical approach (96%). The in-hospital complication rate, excluding vocal cord issues, was 16%; this included an 8% post-operative leak rate. Twenty-two percent failed initial extubation after repair. A total of 22% of the entire group had vocal cord abnormalities (paralysis or paresis) on laryngoscopy that were likely because of recurrent laryngeal nerve injury. Nine percent required a tracheostomy. Only 3% had a recurrent fistula, all of which were treated with reoperation. CONCLUSIONS: There is a high rate of recurrent laryngeal nerve injury after H-type TEF repair. This underscores the need for meticulous surgical technique at the initial repair and suggests that early vocal cord evaluation should be performed for any post-operative respiratory difficulty. Routine evaluation of vocal cord function after H-type TEF repair should be considered. THE LEVEL OF EVIDENCE RATING: Level IV.

A Study of VITOM in Pediatric Surgery and Urology: Evaluation of Technology Acceptance and Usability by Operating Team and Surgeon Musculoskeletal Discomfort.

INTRODUCTION: We studied operating team acceptability of Video Telescopic Monitor (VITOM®) exoscope by exploring the ease of use of the device in two centers. We also assessed factors affecting surgeon musculoskeletal discomfort. METHODS: We focused on how the operating team interacted with the VITOM system with surrogate measures of usefulness, image quality, ease of use, workload, and setup time. Multivariable linear regression was used to model the relationships between team role, experience, and setup time. Relationships between localized musculoskeletal discomfort and use of VITOM alone, and with loupes, were also analyzed. RESULTS: Four surgeons, 7 surgical techs, 7 circulating nurses, and 13 surgical residents performed 70 pediatric surgical and urological operations. We found that subjective views of each team member were consistently positive with 69%-74% agreed or strongly agreed that VITOM enhanced their ability to perform their job and improved the surgical process. Unexpectedly, the scrub techs and nurses perceived more value and utility of VITOM, presumably because it provides them a view of the operative field that would otherwise be unavailable to them. Team members rated perceptions of image quality highly and workload generally satisfactory. Not surprisingly, setup time decreased with team experience and multivariable modeling showed significant correlations with surgeon and surgical tech experience, but not circulating nurse. An important finding was that surgeon neck discomfort was reduced with use of VITOM alone for magnification, compared with use of loupes and VITOM. The most likely explanation for these findings is improved posture with the neck at a neutral position when viewing the VITOM images, compared with neck flexion with loupes, and thus, a less favorable ergonomic position. CONCLUSION: This study suggests that there may be small drawbacks associated with VITOM use initially, but these reduce with increased experience and benefit both the surgeon and the rest of the team.

Laparoscopic stereoscopic augmented reality: toward a clinically viable electromagnetic tracking solution.

The purpose of this work was to develop a clinically viable laparoscopic augmented reality (AR) system employing stereoscopic (3-D) vision, laparoscopic ultrasound (LUS), and electromagnetic (EM) tracking to achieve image registration. We investigated clinically feasible solutions to mount the EM sensors on the 3-D laparoscope and the LUS probe. This led to a solution of integrating an externally attached EM sensor near the imaging tip of the LUS probe, only slightly increasing the overall diameter of the probe. Likewise, a solution for mounting an EM sensor on the handle of the 3-D laparoscope was proposed. The spatial image-to-video registration accuracy of the AR system was measured to be [Formula: see text] and [Formula: see text] for the left- and right-eye channels, respectively. The AR system contributed 58-ms latency to stereoscopic visualization. We further performed an animal experiment to demonstrate the use of the system as a visualization approach for laparoscopic procedures. In conclusion, we have developed an integrated, compact, and EM tracking-based stereoscopic AR visualization system, which has the potential for clinical use. The system has been demonstrated to achieve clinically acceptable accuracy and latency. This work is a critical step toward clinical translation of AR visualization for laparoscopic procedures.

Laparoscopic Gastrostomy Is Superior to Percutaneous Endoscopic Gastrostomy Tube Placement in Children Less Than 5 years of Age.

PURPOSE: Minimally invasive procedures for enteral access in children have evolved over the years, resulting in various techniques of gastrostomy tube placement. The two most common techniques are laparoscopic gastrostomy (LG) and percutaneous endoscopic gastrostomy (PEG). Our study compares the outcomes of both procedures exclusively in children under the age of five. METHODS: All procedures relating to enteral access in children <5 years of age were reviewed retrospectively from July 2009 to July of 2014 as approved by our Institutional Review Board. Demographics, techniques, and complications were collected and analyzed. RESULTS: Of 293 patients in our study, 150 patients underwent PEG, 75 LG, and 68 LG with Nissen fundoplication (LNG). The most common indication for enteral tube placement was failure to thrive and feeding intolerance. Operative time was less in the PEG group than in the other two groups (P = .001). Overall complication rate was 60% for LG and LNG and 58% for PEG (P = NS). The major complication rate was 3.3% in the PEG group and 0.7% for the LG and LNG groups. There were two deaths in the PEG group. Sixty-eight patients (45.3%) from the PEG group underwent tube changes under anesthesia, requiring additional trip to the operating room with general anesthesia compared with LG and LNG groups (2%) (P = .001). From the PEG group, 134 patients (89%) required many fluoroscopic interventions for tube dislodgments and conversion to gastrojejunostomy tubes for significant reflux and inability to use the gastrostomy (P = .001). CONCLUSION: PEG tubes had a higher major complication rate than LG tubes with or without fundoplication in children <5 years of age. Despite longer operative time, LG seems to be the procedure of choice for children of this age for enteral access. Elimination of unnecessary tube changes under anesthesia and the fluoroscopic interventions after the PEG would be beneficial.

Surgical management of esophageal achalasia: Evolution of an institutional approach to minimally invasive repair.

BACKGROUND: Surgical management of esophageal achalasia (EA) in children has transitioned over the past 2 decades to predominantly involve laparoscopic Heller myotomy (LHM) or minimally invasive surgery (MIS). More recently, peroral endoscopic myotomy (POEM) has been utilized to treat achalasia in children. Since the overall experience with surgical management of EA is contingent upon disease incidence and surgeon experience, the aim of this study is to report a single institutional contemporary experience for outcomes of surgical treatment of EA by LHM and POEM, with regards to other comparable series in children. METHODS: An IRB approved retrospective review of all patients with EA who underwent treatment by a surgical approach at a tertiary US children's hospital from 2006 to 2015. Data including demographics, operative approach, Eckardt scores pre- and postoperatively, complications, outcomes, and follow-up were analyzed. RESULTS: A total of 33 patients underwent 35 operative procedures to treat achalasia. Of these operations; 25 patients underwent laparoscopic Heller myotomy (LHM) with Dor fundoplication; 4 patients underwent LHM alone; 2 patients underwent LHM with Thal fundoplication; 2 patients underwent primary POEM; 2 patients who had had LHM with Dor fundoplication underwent redo LHM with takedown of Dor fundoplication. Intraoperative complications included 2 mucosal perforations (6%), 1 aspiration, 1 pneumothorax (1 POEM patient). Follow ranged from 8months to 7years (8-84months). There were no deaths and no conversions to open operations. Five patients required intervention after surgical treatment of achalasia for recurrent dysphagia including 3 who underwent between 1 and 3 pneumatic dilations; and 2 who had redo LHM with takedown of Dor fundoplication with all patients achieving complete resolution of symptoms. CONCLUSIONS: Esophageal achalasia in children occurs at a much lower incidence than in adults as documented by published series describing the surgical treatment in children. We believe the MIS surgical approach remains the standard of care for this condition in children and describe the surgical outcomes and complications for LHM, as well as, the introduction of the POEM technique in our center for treating achalasia. Our institutional experience described herein represents the largest in the "MIS era" with excellent results. We will refer to alterations in our practice that have included the use of flexible endoscopy in 100% of LHM cases and use of the endoscopic functional lumen imaging probe (EndoFLIP) in both LHM and POEM cases which we believe enables adequate Heller myotomy.

On-demand calibration and evaluation for electromagnetically tracked laparoscope in augmented reality visualization.

PURPOSE: Common camera calibration methods employed in current laparoscopic augmented reality systems require the acquisition of multiple images of an entire checkerboard pattern from various poses. This lengthy procedure prevents performing laparoscope calibration in the operating room (OR). The purpose of this work was to develop a fast calibration method for electromagnetically (EM) tracked laparoscopes, such that the calibration can be performed in the OR on demand. METHODS: We designed a mechanical tracking mount to uniquely and snugly position an EM sensor to an appropriate location on a conventional laparoscope. A tool named fCalib was developed to calibrate intrinsic camera parameters, distortion coefficients, and extrinsic parameters (transformation between the scope lens coordinate system and the EM sensor coordinate system) using a single image that shows an arbitrary portion of a special target pattern. For quick evaluation of calibration results in the OR, we integrated a tube phantom with fCalib prototype and overlaid a virtual representation of the tube on the live video scene. RESULTS: We compared spatial target registration error between the common OpenCV method and the fCalib method in a laboratory setting. In addition, we compared the calibration re-projection error between the EM tracking-based fCalib and the optical tracking-based fCalib in a clinical setting. Our results suggest that the proposed method is comparable to the OpenCV method. However, changing the environment, e.g., inserting or removing surgical tools, might affect re-projection accuracy for the EM tracking-based approach. Computational time of the fCalib method averaged 14.0 s (range 3.5 s-22.7 s). CONCLUSIONS: We developed and validated a prototype for fast calibration and evaluation of EM tracked conventional (forward viewing) laparoscopes. The calibration method achieved acceptable accuracy and was relatively fast and easy to be performed in the OR on demand.

Evaluating the impact of a minimally invasive pediatric surgeon on hospital practice: comparison of two children's hospitals.

PURPOSE: Widespread adoption of minimally invasive surgery (MIS) techniques in pediatric surgery has progressed slowly, and the shift in practice patterns has been variable among surgeons. We hypothesized that a pediatric surgeon committed to MIS could effectively change surgical practice by creating an emphasis on MIS. METHODS: Annual case volumes from 2000 to 2009 at two tertiary care pediatric hospitals, one with a dedicated minimally invasive pediatric surgeon, were evaluated for trends in MIS for ten different operations. Univariate analyses of the differences between hospitals in the use of the open versus laparoscopic approach were performed. The Breslow-Day test was used to examine differences in use of laparoscopic procedures across hospitals in early versus middle and middle versus late time periods. RESULTS: Between the two hospitals, for 9 of the 10 types of surgery, the number of laparoscopic and open procedures differed significantly (p values ranged from <0.0001 to 0.003). Over the 10-year period, the hospital with a dedicated MIS surgeon had a larger proportion of procedures done laparoscopically for all years. This difference reached statistical significance for appendectomy (p < 0.0001), congenital diaphragmatic hernia (p < 0.0002), chest wall reconstruction (p < 0.0001), cholecystectomy (p = <0.0001), gastrostomy (p < 0.0001), nissen fundoplication (p < 0.0001) oophorectomy (p < 0.0001), pyloromyotomy (p < 0.0001) and splenectomy (p = 0.0006). After grouping the years into early (2000-2003), middle (2004-2006) and late (2007-2009) categories, the hospital with a dedicated MIS surgeon had a significantly higher rate of increase in use of laparoscopic surgery between the early and middle years for four procedures: diaphragmatic hernia repair (p = 0.003), chest wall reconstruction (p = 0.0086), cholecystectomy (0.0083) and endorectal pull-through (p = 0.025). CONCLUSION: The presence of a dedicated minimally invasive pediatric surgeon led to a significant change in surgical practice with an overall trend of increasing MIS several years in advance of a hospital that did not have a dedicated MIS surgeon. This has implications for resident training in academic medical centers and potential patient care outcomes.

Minimally invasive percutaneous pericardial ICD placement in an infant piglet model: Head-to-head comparison with an open surgical thoracotomy approach.

BACKGROUND: Epicardial implantable cardioverter-defibrillator (ICD) placement in infants, children, and patients with complex cardiac anatomy requires an open surgical thoracotomy and is associated with increased pain, longer length of stay, and higher cost. OBJECTIVE: The purpose of this study was to compare an open surgical epicardial placement approach with percutaneous pericardial placement of an ICD lead system in an infant piglet model. METHODS: Animals underwent either epicardial placement by direct suture fixation through a left thoracotomy or minimally invasive pericardial placement with thoracoscopic visualization. Initial lead testing and defibrillation threshold testing (DFT) were performed. After the 2-week survival period, repeat lead testing and DFT were performed before euthanasia. RESULTS: Minimally invasive placement was performed in 8 piglets and open surgical placement in 7 piglets without procedural morbidity or mortality. The mean initial DFT value was 10.5 J (range 3-28 J) in the minimally invasive group and 10.0 J (range 5-35 J) in the open surgical group (P = .90). After the survival period, the mean DFT value was 12.0 J (range 3-20 J) in the minimally invasive group and 12.3 J (range 3-35 J) in the open surgical group (P = .95). All lead and shock impedances, R-wave amplitudes, and ventricular pacing thresholds remained stable throughout the survival period. CONCLUSION: Compared with open surgical epicardial ICD lead placement, minimally invasive pericardial placement demonstrates an equivalent ability to effectively defibrillate the heart and has demonstrated similar lead stability. With continued technical development and operator experience, the minimally invasive method may provide a viable alternative to epicardial ICD lead placement in infants, children, and adults at risk of sudden cardiac death.