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Dive into the research topics where Christy M. Dunst is active.

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Featured researches published by Christy M. Dunst.


Annals of Surgery | 2012

Long-term outcomes of an endoscopic myotomy for achalasia: the POEM procedure.

Lee L. Swanstrom; Ashwin A. Kurian; Christy M. Dunst; Ahmed Sharata; Neil H. Bhayani; Erwin Rieder

Background:Esophageal achalasia is most commonly treated with laparoscopic myotomy or endoscopic dilation. Per-oral endoscopic myotomy (POEM), an incisionless selective myotomy, has been described as a less invasive surgical treatment. This study presents 6-month physiological and symptomatic outcomes after POEM for achalasia. Methods:Data on single-institution POEMs were collected prospectively. Pre- and postoperative symptoms were quantified with Eckardt scores. Objective testing (manometry, endoscopy, timed-barium swallow) was performed preoperatively and 6 months postoperatively. At 6 months, gastroesophageal reflux was evaluated by 24-hour pH testing. Pre-/postmyotomy data were compared using paired nonparametric statistics. Results:Eighteen achalasia patients underwent POEMs between October 2010 and October 2011. The mean age was 59 ± 20 years and mean body mass index was 26 ± 5 kg/m2. Six patients had prior dilations or Botox injections. Myotomy length was 9 cm (7–12 cm), and the median operating time was 135 minutes (90–260). There were 3 intraoperative complications: 2 gastric mucosotomies and 1 full-thickness esophagotomy, all repaired endoscopically with no sequelae. The median hospital stay was 1 day and median return to normal activity was 3 days (3–9 days). All patients had relief of dysphagia [dysphagia score ⩽ 1 (“rare”)]. Only 2 patients had Eckardt scores greater than 1, due to persistent noncardiac chest pain. At a mean follow-up of 11.4 months, dysphagia relief persisted for all patients. Postoperative manometry and timed barium swallows showed significant improvements in lower esophageal relaxation characteristics and esophageal emptying, respectively. Objective evidence of gastroesophageal reflux was seen in 46% patients postoperatively. Conclusions:POEM is safe and effective. All patients had dysphagia relief, 83% having relief of noncardiac chest pain. There is significant though mild gastroesophageal reflux postoperatively in 46% of patients in 6-month pH studies. The lower esophageal sphincter shows normalized pressures and relaxation.


Annals of Surgery | 2014

A Comparative Study on Comprehensive, Objective Outcomes of Laparoscopic Heller Myotomy With Per-Oral Endoscopic Myotomy (POEM) for Achalasia

Neil H. Bhayani; Ashwin A. Kurian; Christy M. Dunst; Ahmed M. Sharata; Erwin Rieder; Lee L. Swanstrom

Objective:To compare symptomatic and objective outcomes between HM and POEM. Background:The surgical gold standard for achalasia is laparoscopic Heller myotomy (HM) and partial fundoplication. Per-oral endoscopic myotomy (POEM) is a less invasive flexible endoscopic alternative. We compare their safety and efficacy. Methods:Data on consecutive HMs and POEMs for achalasia from 2007 to 2012 were collected. Primary outcomes: swallowing function—1 and 6 months after surgery. Secondary outcomes: operative time, complications, postoperative gastro-esophageal reflux disease (GERD). Results:There were 101 patients: 64 HMs (42% Toupet and 58% Dor fundoplications) and 37 POEMs. Presenting symptoms were comparable. Median operative time (149 vs 120 min, P < 0.001) and mean hospitalization (2.2 vs 1.1 days, P < 0.0001) were significantly higher for HMs. Postoperative morbidity was comparable. One-month Eckardt scores were significantly better for POEMs (1.8 vs 0.8, P < 0.0001). At 6 months, both groups had sustained similar improvements in their Eckardt scores (1.7 vs 1.2, P = 0.1).Both groups had significant improvements in postmyotomy lower esophageal sphincter profiles. Postmyotomy resting pressures were higher for POEMs than for HMs (16 vs 7.1 mm Hg, P = 0.006). Postmyotomy relaxation pressures and distal esophageal contraction amplitudes were not significantly different between groups. Routine postoperative 24-hour pH testing was obtained in 48% Hellers and 76% POEMs. Postoperatively, 39% of POEMs and 32% of HM had abnormal acid exposure (P = 0.7). Conclusions:POEM is an endoscopic therapy for achalasia with a shorter hospitalization than HM. Patient symptoms and esophageal physiology are improved equally with both procedures. Postoperative esophageal acid exposure is the same for both. The POEM is comparable with laparoscopic HM for safe and effective treatment of achalasia.


Gastrointestinal Endoscopy | 2013

Peroral endoscopic esophageal myotomy: defining the learning curve

Ashwin A. Kurian; Christy M. Dunst; Ahmed Sharata; Neil H. Bhayani; Kevin M. Reavis; Lee L. Swanstrom

BACKGROUND Peroral endoscopic myotomy (POEM) is an endoscopic alternative to laparoscopic esophageal myotomy. It requires a demanding skill set that involves both advanced endoscopic skills and knowledge of surgical anatomy and complication management. OBJECTIVE Determine the learning curve for POEM. DESIGN Prospective cohort study. SETTING Tertiary-care teaching hospital. PATIENTS The study involved the first 40 consecutive patients undergoing the POEM procedure under a prospective institutional review board protocol (research.gov #NCT01399476, 1056). INTERVENTION Peroral endoscopic myotomy for esophageal motility disorders. MAIN OUTCOME MEASUREMENTS Length of procedure (LOP) and technical errors (inadvertent mucosotomy). RESULTS A total of 40 patients underwent POEM. The mean LOP was 126 ± 41 minutes. The mean myotomy length was 9 cm (range, 6-20 cm). The LOP per centimeter myotomy and variability decreased as our experience progressed. The means (± standard deviation) of the LOP per centimeter myotomy were as follows: first cohort, 16 ± 4 minutes; second, 17 ± 5 minutes; third, 13 ± 3 minutes; fourth, 15 ± 2 minutes; and fifth, 13 ± 4 minutes. The incidence of inadvertent mucosotomy also decreased with increasing experience, to 8, 6, 4, 0, and 1, respectively. These minor complications were repaired intraoperatively with clips. There were 7 patients with capnoperitonium and another with bilateral capnothoraces that were associated with hemodynamic instability but resolved by Veress needle decompression. Two patients required endoscopy in the early postoperative period: self-limited hematemesis in one and radiologic evidence of leakage at the mucosotomy site in another. LIMITATIONS Nonrandomized study. CONCLUSION Mastery of operative technique in POEM is evidenced by a decrease in LOP, variability of minutes per centimeter of myotomy, and incidence of inadvertent mucosotomies and plateaus in about 20 cases for experienced endoscopists. The learning curve can be shortened with very close supervision and/or proctoring.


Journal of The American College of Surgeons | 2011

A Stepwise Approach and Early Clinical Experience in Peroral Endoscopic Myotomy for the Treatment of Achalasia and Esophageal Motility Disorders

Lee L. Swanstrom; Erwin Rieder; Christy M. Dunst

BACKGROUND Peroral endoscopic myotomy (POEM) has recently been described in humans as a treatment for achalasia. This concept has evolved from developments in natural orifice translumenal endoscopic surgery (NOTES) and has the potential to become an important therapeutic option. We describe our approach as well as our initial clinical experience as part of an ongoing study treating achalasia patients with POEM. STUDY DESIGN Five patients (mean age 64 ± 11 years) with esophageal motility disorders were enrolled in an IRB-approved study and underwent POEM. This completely endoscopic procedure involved a midesophageal mucosal incision, a submucosal tunnel onto the gastric cardia, and selective division of the circular and sling fibers at the lower esophageal sphincter. The mucosal entry was closed by conventional hemostatic clips. All patients had postoperative esophagograms before discharge and initial clinical follow-up 2 weeks postoperatively. RESULTS All (5 of 5) patients successfully underwent POEM treatment, and the myotomy had a median length of 7 cm (range 6 to 12 cm). After the procedure, smooth passage of the endoscope through the gastroesophageal junction was observed in all patients. Operative time ranged from 120 to 240 minutes. No leaks were detected in the swallow studies and mean length of stay was 1.2 ± 0.4 days. No clinical complications were observed, and at the initial follow-up, all patients reported dysphagia relief without reflux symptoms. CONCLUSIONS Our initial experience with the POEM procedure demonstrates its operative safety, and early clinical results have shown good results. Although further evaluation and long-term data are mandatory, POEM could become the treatment of choice for symptomatic achalasia.


Journal of The American College of Surgeons | 2002

A review of technical aspects of sentinel lymph node identification for breast cancer

Todd M Tuttle; Theresa G Zogakis; Christy M. Dunst; Richard T. Zera; S. Eva Singletary

The management of lymph nodes in breast cancer has undergone significant changes over the past century. In the Halsted radical mastectomy, axillary lymph nodes were removed en bloc with the breast and pectoralis muscles. After World War II, Waangensteen and others advocated removing the supraclavicular and internal mammary lymph nodes and the axillary nodes. More recently, others have suggested that removing clinically normal axillary lymph nodes is not therapeutic, so is unnecessary. But the status of the axillary lymph node basin remains the most powerful predictor of longterm survival in patients with breast cancer. Furthermore, pathologic analysis of the axillary nodes provides essential information for determining adjuvant therapies. Until recently, a level I/II axillary lymph node dissection (ALND) was the recommended method for identifying nodal metastases. But ALND is associated with numerous side effects, including arm numbness and pain, fluid collections, infections, and lymphedema. Because most breast cancer patients today do not have lymph node metastases, ALND offers no benefit, and may, in fact, do harm to many patients. Sentinel lymph node (SLN) biopsy has been proposed as a substitute for routine ALND in patients with clinically normal axillary basins. The SLN, the first node to receive primary lymphatic drainage from the breast, may be used to predict the status of the remainder of the axilla. A patient with a negative SLN biopsy may be spared the risks of unnecessary ALND. Early investigators attempted to identify the SLN using peritumoral injections of either blue dye or radioactive colloid, or both. In preliminary studies, SLN biopsy was followed by ALND to determine the accuracy of the biopsy results. SLN biopsy results are assessed by identification rates and false-negative rates. If the SLN is not identified, an ALND should be performed. So a high identification rate is desired to reduce unnecessary ALNDs. A falsenegative result in a patient with breast cancer is especially troublesome; cancerous lymph nodes can be left untreated in the axilla, and, more important, appropriate adjuvant therapy might not be implemented. Overall, identification rates and false-negative rates vary considerably among surgeons and might be related to the lack of a standardized technique to identify the SLN. Despite the widespread use of SLN biopsy, a number of technical questions remain: Where should the tracer be injected? What volume of radioactive colloid should be used? Is the use of dual agents better than a single agent? What is the value of preoperative lymphoscintigraphy? Should internal mammary lymph nodes be removed? Is filtered radioactive colloid better than unfiltered? When should the tracer agents be injected? The literature now includes several hundred publications with more than 10,000 patients undergoing SLN biopsy using various techniques. In many cases, individual authors advocate the particular technique used at their own institution. An overview analysis is limited by retrospective studies, various degrees of surgeon experience, conflicting indications for the procedure, and the evolution of technology over the past several years. Nevertheless, a critical and objective review is important to provide the practicing general surgeon guidelines for accurate SLN identification.


Journal of Gastrointestinal Surgery | 2011

Paraesophageal Hernia Repair with Biomesh Does Not Increase Postoperative Dysphagia

Trudie A. Goers; Maria A. Cassera; Christy M. Dunst; Lee L. Swanstrom

IntroductionLaparoscopic techniques have led to hiatal procedures being performed with less morbidity but higher failure rates. Biologic mesh (biomesh) has been proposed as an alternative to plastic mesh to achieve durable repairs while minimizing stricturing and erosion. This paper documents the lack of significant dysphagia after the placement of biomesh during hiatal hernia repair.MethodsA retrospective chart review of patients who underwent paraesophageal hiatal hernia repairs with and without biomesh was performed. Hernias were diagnosed with esophagogastroscopy and esophageal manometry. Demographic, procedural, and pre- and post-surgery symptom data were recorded.ResultsFifty-six patients underwent biomesh repair while 33 patients underwent non-mesh repairs. The procedure time for mesh repairs was significantly longer (p = 0.004). Hospital stays, resting lower esophageal sphincter pressure, and mean contraction amplitudes were similar between groups. Residual pressure was measured to be significantly higher in patients who had mesh repairs (p = 0.0001). Normal esophageal peristalsis was maintained in both groups. At first follow-up, mesh patients complained of more dysphagia and bloating, but non-mesh patients had more heartburn. At second follow-up, non-mesh patients had more symptom complaints than mesh patients.ConclusionThe addition of biomesh for hiatal hernia repair does not result in significantly increased patient dysphagia rates postoperatively compared with patients who underwent primary repair.


JAMA Surgery | 2013

Partial Anterior vs Partial Posterior Fundoplication Following Transabdominal Esophagocardiomyotomy for Achalasia of the Esophagus Meta-regression of Objective Postoperative Gastroesophageal Reflux and Dysphagia

Ashwin A. Kurian; Neil H. Bhayani; Ahmed Sharata; Kevin M. Reavis; Christy M. Dunst; Lee L. Swanstrom

OBJECTIVES To review transabdominal esophagocardiomyotomy (surgical treatment of achalasia) of the esophagus and to compare outcomes of partial anterior vs partial posterior fundoplication. DATA SOURCES An electronic search was conducted among studies published between January 1976 and September 2011 using the keywords achalasia, myotomy, antireflux surgery, and fundoplication. STUDY SELECTION Prospective studies of transabdominal esophagocardiomyotomy were selected. DATA EXTRACTION Outcomes selected were recurrent or persistent postoperative dysphagia and an abnormal 24-hour pH test result. Studies were divided into the following 3 groups: myotomy only, myotomy with anterior fundoplication, and myotomy with posterior fundoplication. Studies were weighted by the number of patients and by the follow-up duration. Event rates were calculated using meta-regression of the log-odds with the inverse variance method. DATA SYNTHESIS Thirty-nine studies with a total of 2998 patients were identified. The odds of postoperative dysphagia were 0.06 (95% CI, 0.03-0.12) for myotomy only, 0.11 (95% CI, 0.09-0.14) for myotomy with anterior fundoplication, and 0.06 (95% CI, 0.04-0.08) for myotomy with posterior fundoplication. The odds of a postoperative abnormal 24-hour pH test result were 0.37 (95% CI, 0.12-1.08) for myotomy only, 0.16 (95% CI, 0.11-0.24) for myotomy with anterior fundoplication, and 0.18 (95% CI, 0.13-0.25) for myotomy with posterior fundoplication. The increased odds of postoperative dysphagia in the group undergoing myotomy with anterior fundoplication compared with the group undergoing myotomy with posterior fundoplication were statistically significant (P < .001). However, the incidence of a postoperative abnormal 24-hour pH test result was statistically similar. CONCLUSION Partial posterior fundoplication when combined with an esophagocardiomyotomy may be associated with significantly lower reintervention rates for postoperative dysphagia, while providing similar reflux control compared with partial anterior fundoplication.


Journal of Gastrointestinal Surgery | 2015

End of the Road for a Dysfunctional End Organ: Laparoscopic Gastrectomy for Refractory Gastroparesis

Neil H. Bhayani; Ahmed M. Sharata; Christy M. Dunst; Ashwin A. Kurian; Kevin M. Reavis; Lee L. Swanstrom

IntroductionGastroparesis is a functional disorder resulting in debilitating nausea, esophageal reflux, and abdominal pain and is frequently refractory to medical treatment. Therapies such as pyloroplasty and neurostimulators can improve symptoms. When medical and surgical treatments fail, palliative gastrectomy is an option. We examined outcomes after gastrectomy for postoperative, diabetic, and idiopathic gastroparesis.MethodsA prospective database was queried for gastrectomies performed for gastroparesis from 1999 to 2013. Primary outcomes were improvements in pre- versus postoperative symptoms at last follow-up, measured on a five-point scale. Secondary outcome was operative morbidity.ResultsThirty-five patients underwent laparoscopic total or near-total gastrectomies for postoperative (43 %), diabetic (34 %), or idiopathic (23 %) gastroparesis. Antiemetics and prokinetics afforded minimal relief for one third of patients. There were no mortalities. Six patients suffered a leak, all treated with surgical reintervention. With a median follow-up of 6 months, nausea improved or resolved in 69 %. Chronic abdominal pain improved or resolved in 70 %. Belching and bloating resolved for 79 and 89 %, respectively (p < 0.01).ConclusionsRegardless of etiology, medically refractory gastroparesis can be a devastating disease. Near-total gastrectomy can ameliorate or relieve nausea, belching, and bloating. Chronic abdominal pain commonly resolved or improved with resection. Despite attendant morbidity, gastrectomy can effectively palliate symptoms of gastroparesis.


The Annals of Thoracic Surgery | 2013

Does Morbid Obesity Worsen Outcomes After Esophagectomy

Neil H. Bhayani; Aditya Gupta; Christy M. Dunst; Ashwin A. Kurian; Valerie J. Halpin; Lee L. Swanstrom

BACKGROUND With worldwide increases in esophageal cancer and obesity, esophagectomies in the morbidly obese (MO) will only increase. Risk stratification and patient counseling require more information on the morbidity associated with esophagectomy in the obese. METHODS We studied nonemergent subtotal or total esophagectomies with reconstruction in the National Surgical Quality Improvement Project (NSQIP) database from 2005 to 2010. After excluding patients with disseminated disease and body mass index (BMI) less than 18.5, we compared outcomes of patients with normal BMI (18.5-25) to those of MO patients (BMI ≥ 35). Outcomes were mortality and morbidity. Multivariable regression controlled for age and comorbidities differing between groups. RESULTS Of 794 patients, 578 (73%) had a normal BMI and 216 (27%) patients were morbidly obese (MO). The population was 75% men, with a mean age of 62 years. Patients with a normal BMI were older and more likely to smoke (p < 0.001). MO patients had a higher incidence of hypertension (65% versus 41%) and diabetes (20% versus 10%), and fewer had preoperative weight loss greater than 10% (9% versus 31%) (p < 0.001). Overall, morbidity was 48.5% and mortality was 3%; there was no difference between the groups. On multivariable analysis, all outcomes were the same between groups except deep space infections and pulmonary embolism (PE), for which the obese were at 52% and 48% higher risk, respectively (p = 0.02). CONCLUSIONS In our study, postoperative mortality and pulmonary, cardiac, and thromboembolic morbidity were similar between MO patients and patients with a normal BMI. MO increased the odds of deep wound infections. Overall, BMI greater than 35 does not confer significant morbidity after esophagectomy. Patients with esophageal pathologic conditions should not be denied resection based on MO alone.


Journal of The American College of Surgeons | 2011

Concomitant Endoscopic Radiofrequency Ablation and Laparoscopic Reflux Operative Results in More Effective and Efficient Treatment of Barrett Esophagus

Trudie A. Goers; Pedro Leão; Maria A. Cassera; Christy M. Dunst; Lee L. Swanstrom

BACKGROUND Barrett esophagus (BE) caused by gastroesophageal reflux disease can lead to esophageal cancer. The success of endoscopic treatments with BE eradication depends on esophageal anatomy and post-treatment acid exposure. STUDY DESIGN Between January 2008 and December 2009, 10 patients were selected for combination treatment of BE using laparoscopic anti-reflux surgery and endoscopic radiofrequency ablation. Retrospective review of preoperative, procedural, and postoperative data was performed. RESULTS Seven study patients had a pathologic diagnosis of nondysplastic BE and 3 patients had a diagnosis of low-grade dysplasia. Average length of BE lesions was 6.4 ± 4.8 cm. Procedure time averaged 154.4 ± 46.4 minutes. At the time of surgery, the mean number of ablations performed was 4.39 ± 1.99. Six patients were noted to have major hiatal hernias requiring reduction. Five patients (80%) had 100% resolution of their BE at their first postoperative endoscopy. The remaining 3 patients had a ≥50% resolution and underwent subsequent endoscopic ablation. Symptomatic results revealed that 4 patients had substantial dysphagia to solids and other symptoms were minimal. Two patients were noted to have complications related to the ablative treatments. One stricture and 1 perforation were observed. CONCLUSIONS Endoscopic radiofrequency ablation of BE at the time of laparoscopic fundoplication is feasible and can effectively treat BE lesions. A single combined treatment can result in fewer overall procedures performed to obtain BE eradication.

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Dive into the Christy M. Dunst's collaboration.

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Lee L. Swanstrom

Providence Portland Medical Center

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Ashwin A. Kurian

Abington Memorial Hospital

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Neil H. Bhayani

Pennsylvania State University

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Steven R. DeMeester

University of Southern California

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Ahmed M. Sharata

Providence Portland Medical Center

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Maria A. Cassera

Providence Portland Medical Center

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Brian E. Louie

University of Southern California

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