Scholars@Duke
Dana Dale Portenier

Dana Dale Portenier

Associate Professor of Surgery
Surgery, Minimally Invasive Surgery
dana.portenier@duke.edu
Box 3351 Med Ctr, Durham, NC 27710
407 Crutchfield St, Durham, NC 27704

Scholarly Works - Journal articles

The functional lumen opening with self-forming magnetic anastomosis (FLOWS) study: results from the North American pivotal trial.

Journal article Surg Endosc · September 2026 OBJECTIVE: To evaluate the safety and effectiveness of using self-forming magnets (SFM) with an immediately functional lumen for the creation of small bowel anastomoses. BACKGROUND: Prevention of short-, medium-, and long-term gastrointestinal anastomotic ... Full text Link to item Cite

Postoperative outcomes following revision or conversion surgery after primary sleeve gastrectomy: an analysis of the MBSAQIP database.

Journal article Surg Obes Relat Dis · August 2025 BACKGROUND: A significant proportion of patients that undergo primary sleeve gastrectomy (SG) require revision or conversion metabolic and bariatric surgery (MBS). Despite various procedures performed in practice, comparative analyses of short-term outcome ... Full text Link to item Cite

The Role of Sleep Apnea in Postoperative Neurocognitive Disorders Among Older Noncardiac Surgery Patients: A Prospective Cohort Study.

Journal article Anesth Analg · January 1, 2025 BACKGROUND: Obstructive sleep apnea is associated with increased dementia risk, yet its role in postoperative neurocognitive disorders is unclear. Here, we studied whether the severity of untreated obstructive sleep apnea is associated with the severity of ... Full text Open Access Link to item Cite

Magnetic-assisted surgery: The road from laparoscopy to robotics

Journal article Mini Invasive Surgery · January 1, 2022 The incorporation of magnetic fields into surgery to reduce the invasiveness of minimally invasive surgery led to the creation of magnetic-assisted surgery. External magnets coupled with their internal counterparts assist during surgical procedures, avoidi ... Full text Cite

Metabolic profiles, energy expenditures, and body compositions of the weight regain versus sustained weight loss patients who underwent Roux-en-Y gastric bypass.

Journal article Surg Obes Relat Dis · December 2021 BACKGROUND: Weight regain (WR) has been an emerging problem after Roux-en Y gastric bypass (RYGB) and little is known about the mechanisms of WR after RYGB. OBJECTIVE: To evaluate the mechanisms of WR after RYGB through the postprandial gut hormones respon ... Full text Link to item Cite

Technical Feasibility, Outcomes, and Patient Satisfaction After Needlescopic and Laparoscopic Bariatric Surgery: a Randomized Study.

Journal article Obes Surg · November 2021 BACKGROUND: Needlescopic instruments create a 3-mm incision and may result in less pain and superior cosmesis. There is limited understanding of the effectiveness of needlescopic instruments in patients with a body mass index (BMI) > 35 kg/m2. We report pe ... Full text Link to item Cite

Glycemic Control Predicts Severity of Hepatocyte Ballooning and Hepatic Fibrosis in Nonalcoholic Fatty Liver Disease.

Journal article Hepatology · September 2021 BACKGROUND AND AIMS: Whether glycemic control, as opposed to diabetes status, is associated with the severity of NAFLD is open for study. We aimed to evaluate whether degree of glycemic control in the years preceding liver biopsy predicts the histological ... Full text Open Access Link to item Cite

Sexual and Gender Minority Bariatric Patients: An Unseen Population

Journal article Bariatric Surgical Practice and Patient Care · March 1, 2021 Background: This article has two aims: review current literature addressing sexual and gender minority (SGM) bariatric patients and describe a pilot study identifying sexual minority (SM) bariatric patients at an academic medical center. Methods: The liter ... Full text Cite

Magnetic Liver Retraction Decreases Postoperative Pain and Length of Stay in Bariatric Surgery Compared to Nathanson Device.

Journal article J Laparoendosc Adv Surg Tech A · February 2021 Objective: Retrospective case-matched comparison of magnetic liver retraction to a bedrail-mounted liver retractor in bariatric surgery specifically targeting short-term postoperative outcomes, including pain and resource utilization. Background: Retractio ... Full text Link to item Cite

First prospective clinical trial of reduced incision bariatric procedures using magnetic liver retraction.

Journal article Surg Obes Relat Dis · January 2021 BACKGROUND: Exposure of the surgical field is an essential component of minimally invasive surgery. Liver retraction is an important element of bariatric procedures because visualization of the stomach and gastroesophageal junction is key. The magnetic sur ... Full text Link to item Cite

Informed consent: a shared decision-making process that creates a new professional obligation for care.

Journal article Surg Endosc · November 2020 This statement on informed consent, developed by the SAGES Ethics Committee, has been reviewed and approved by the Board of Governors of SAGES. This statement is provided to offer guidance about the purpose and process of obtaining informed consent, and it ... Full text Open Access Link to item Cite

Performance and improvement of the DiaRem score in diabetes remission prediction: a study with diverse procedure types.

Journal article Surg Obes Relat Dis · October 2020 BACKGROUND: The DiaRem score has proven to be a reliable predictor tool for diabetes remission in Roux-en-Y gastric bypass (RYGB), as well as laparoscopic adjustable gastric band (LAGB) and laparoscopic sleeve gastrectomy (LSG). To our knowledge there are ... Full text Link to item Cite

Racial Disparities in Bariatric Surgery Complications and Mortality Using the MBSAQIP Data Registry.

Journal article Obes Surg · August 2020 BACKGROUND: Racial disparities in postoperative complications have been demonstrated in bariatric surgery, yet the relationship of race to complication severity is unknown. STUDY DESIGN: Adult laparoscopic primary bariatric procedures were queried from the ... Full text Link to item Cite

Determining changes in bone metabolism after bariatric surgery in postmenopausal women.

Journal article Surg Endosc · April 2020 BACKGROUND: Accelerated bone loss is a known complication after bariatric surgery. Bone mineral density has been shown to decrease significantly after Laparoscopic Roux-en-Y gastric bypass (RYGB). Laparoscopic sleeve gastrectomy (SG) effects on bone densit ... Full text Link to item Cite

Scars Matter: The Importance of Incision Decisions in Bariatric Patients.

Journal article Obes Surg · April 2020 This study aims to determine if cosmetic outcomes play an important role for patients undergoing bariatric surgery, when considering a surgical approach. A video-animation describing open, conventional laparoscopic, and reduced incision magnetic assisted s ... Full text Link to item Cite

Single Anastomosis Duodenal Switch: 1-Year Outcomes.

Journal article Obes Surg · April 2020 INTRODUCTION: Single-anastomosis duodenal switch has been suggested to be an effective bariatric procedure that offers excellent weight loss and by lengthening the common channel the potential to reduce micronutrient deficiencies. PURPOSE: To evaluate the ... Full text Link to item Cite

Complications of Robotic Surgery.

Journal article Surg Clin North Am · April 2020 Robotic-assisted surgery has represented a revolution for surgical practice and minimally invasive surgery. The case volume is increasing exponentially and the numbers continue to grow particularly owing to urology and general surgery subspecialties. Nonet ... Full text Link to item Cite

[Endoscopy after bariatric surgery: what the endoscopist must know].

Journal article Rev Med Chil · January 2020 Endoscopy is essential in the assessment and treatment of the bariatric patient, especially in the postoperative state. Since bariatric surgery is increasing exponentially, endoscopists should be familiar with the anatomy and how to manage possible complic ... Full text Link to item Cite

Validation of Serum Test for Advanced Liver Fibrosis in Patients With Nonalcoholic Steatohepatitis.

Journal article Clin Gastroenterol Hepatol · August 2019 BACKGROUND & AIMS: We analyzed markers of fibrosis in serum samples from patients with nonalcoholic fatty liver disease (NAFLD), assessed by liver biopsy. We used serum levels of markers to develop an algorithm to discriminate patients with advanced fibros ... Full text Link to item Cite

Single-Center Experience with Magnetic Retraction in Colorectal Surgery.

Journal article J Laparoendosc Adv Surg Tech A · August 2019 Background: Appropriate tissue retraction is essential in laparoscopic surgery, and colorectal operations often require an additional incision and trocar that can disturb visualization and maneuverability. Each incision carries an increased risk for compli ... Full text Link to item Cite

Asthma medication usage is significantly reduced following bariatric surgery.

Journal article Surg Endosc · June 2019 INTRODUCTION: Asthma is an important healthcare problem affecting millions in the United States. Additionally, a large proportion of patients with asthma suffer from obesity. These patients exhibit poor asthma control and reduced therapy response, increasi ... Full text Open Access Link to item Cite

Use of magnets in gastrointestinal surgery.

Journal article Surg Endosc · June 2019 BACKGROUND: Laparoscopic and endoscopic surgery has undergone vast progress during the last 2 decades, translating into improved patient outcomes. A prime example of this development is the use of magnetic devices in gastrointestinal surgery. Magnetic devi ... Full text Link to item Cite

Magnetic Liver Retraction: an Incision-Less Approach for Less Invasive Bariatric Surgery.

Journal article Obes Surg · March 2019 BACKGROUND: In bariatric surgery, retraction of the liver is essential to ensure appropriate visualization of the surgical field. Many devices are currently employed for this purpose. Generally, these devices require constant use of a port, or an additiona ... Full text Link to item Cite

Current news and trends in gastrointestinal robotic surgery

Journal article Revista De Cirugia · January 1, 2019 It is a fact that we are at a moment in the history of humanity in which the development of technologies has changed our daily lives, as well as that of our daily surgical practice. The fast evolution in technology has allowed surgery to evolve from a rudi ... Cite

Anatomical modifications of the biliopancreatic diversion with duodenal switch: Do they have a future role in bariatric and metabolic surgery?

Journal article Revista De Cirugia · January 1, 2019 Biliopancreatic Diversion with duodenal switch (BPD-DS) is the bariatric surgery that has shown the better results regarding long-term weight loss and comorbidities resolution. Nevertheless, BPD-DS´ adoption has been slow, mainly due to its nutritional com ... Full text Cite

Endoscopic Abscess Septotomy: A Less Invasive Approach for the Treatment of Sleeve Gastrectomy Leaks.

Journal article J Laparoendosc Adv Surg Tech A · July 2018 BACKGROUND: Postoperative leaks develop in a low percentage of patients undergoing laparoscopic sleeve gastrectomy (LSG), representing a rare yet devastating postoperative complication increasing morbidity and hospital stay. Leaks can become collections an ... Full text Link to item Cite

Bariatric surgery in patients with bipolar spectrum disorders: Selection factors, postoperative visit attendance, and weight outcomes.

Journal article Surg Obes Relat Dis · April 2017 BACKGROUND: As many as 3% of bariatric surgery candidates are diagnosed with a bipolar spectrum disorder. OBJECTIVES: 1) To describe differences between patients with bipolar spectrum disorders who are approved and not approved for surgery by the mental he ... Full text Link to item Cite

A Matched Cohort Analysis of Stomach Intestinal Pylorus Saving (SIPS) Surgery Versus Biliopancreatic Diversion with Duodenal Switch with Two-Year Follow-up.

Journal article Obes Surg · February 2017 BACKGROUND: In bariatric surgery, the procedure with the highest average weight loss is the biliopancreatic diversion with duodenal switch (BPDDS). A new simplified duodenal switch called the stomach intestinal pylorus sparing (SIPS) surgery with less mala ... Full text Link to item Cite

Laparoscopic Single-Site Inguinal Hernia Repair Using a Self-Fixating Mesh.

Journal article JSLS · 2017 BACKGROUND AND OBJECTIVES: Every year ∼20 million inguinal hernia repairs are completed worldwide. Increased patient access to medical information and education has elicited interest in minimally invasive surgical techniques that obtain improved surgical o ... Full text Link to item Cite

Predictors of weight regain in patients who underwent Roux-en-Y gastric bypass surgery.

Journal article Surg Obes Relat Dis · November 2016 BACKGROUND: Roux-en-Y gastric bypass (RYGB) is a highly effective treatment for obesity and results in long-term weight loss and resolution of co-morbidities. However, weight regain may occur as soon as 1-2 years after surgery. OBJECTIVES: This retrospecti ... Full text Link to item Cite

Patient Selection and Surgical Management of High-Risk Patients with Morbid Obesity.

Journal article Surg Clin North Am · August 2016 Bariatric surgery is the most effective way to improve comorbidities related to obesity. Since the introduction of minimally invasive laparoscopic surgery in the bariatric surgery techniques, the number of procedures has increased substantially; advances i ... Full text Link to item Cite

Gastric Bypass Surgery Leads to Long-term Remission or Improvement of Type 2 Diabetes and Significant Decrease of Microvascular and Macrovascular Complications.

Journal article Ann Surg · June 2016 OBJECTIVES: The aim of the study was to compare long-term outcomes of 2 groups of morbidly obese patients with type 2 diabetes mellitus-1 managed by Roux-en-Y gastric bypass surgery and a comparable group managed medically. METHODS: The present study was a ... Full text Link to item Cite

Effectiveness of laparoscopic Roux-en-Y gastric bypass on obese class I type 2 diabetes mellitus patients.

Journal article Surg Obes Relat Dis · 2015 BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (LRYGB) can dramatically improve type 2 diabetes mellitus (T2D) in obese class II and III patients. There is increasing evidence that shows bariatric surgery can also ameliorate T2D in patients with BMI bet ... Full text Link to item Cite

Conversion of vertical banded gastroplasty to stand-alone sleeve gastrectomy or biliopancreatic diversion with duodenal switch.

Journal article J Gastrointest Surg · April 2013 INTRODUCTION: Vertical banded gastroplasty (VBG) originated as a simplified bariatric operation to avoid malabsorption and provide lasting results due to a fixed stoma. Short-term results were excellent (50-70 % excess weight loss); however, patients often ... Full text Link to item Cite

Single-incision laparoscopic right colectomy: an efficient technique.

Journal article Surg Laparosc Endosc Percutan Tech · April 2012 PURPOSE: Laparoscopic right colectomy has an established patient benefit. We sought to demonstrate that a single-incision approach to laparoscopic right colectomy is safe, reproducible, and efficient. METHODS: Photographs were acquired from cases to depict ... Full text Link to item Cite

Algorithm to diagnose etiology of hypoglycemia after Roux-en-Y gastric bypass for morbid obesity: case series and review of the literature.

Journal article Surg Obes Relat Dis · 2012 BACKGROUND: Gastric bypass is a proven treatment option for weight loss and the reduction of medical co-morbid conditions in the obese population. Severe refractory and/or recurrent hypoglycemia can occur, especially in postoperative patients who do not co ... Full text Link to item Cite

Weight loss at first postoperative visit predicts long-term outcome of Roux-en-Y gastric bypass using Duke weight loss surgery chart.

Journal article Surg Obes Relat Dis · 2012 BACKGROUND: Roux-en-Y gastric bypass has been used for >3 decades. However, no normative data are available to aid the bariatric surgeon in assessing the adequacy of weight loss at each postoperative visit. The objective of the present study was to constru ... Full text Link to item Cite

In vivo assessment of an absorbable and nonabsorbable knotless barbed suture for laparoscopic single-layer enterotomy closure: a clinical and biomechanical comparison against nonbarbed suture.

Journal article J Laparoendosc Adv Surg Tech A · December 2011 BACKGROUND: Laparoscopic intracorporeal suturing and knot tying is a complex skill that requires repeated deliberate practice to master. A novel self-anchoring barbed suture material that does not require knot tying can eliminate knot failure and reduce op ... Full text Link to item Cite

Clinical Q&A

Journal article Bariatric Nursing and Surgical Patient Care · March 2009 Full text Cite

Remission of type 2 diabetes after Roux-en-Y gastric bypass is associated with greater weight loss.

Journal article Surg Obes Relat Dis · 2009 BACKGROUND: Physiologic studies in rodents and preliminary human studies have suggested that Roux-en-Y gastric bypass (RYGB) improves type 2 diabetes mellitus (T2DM) by way of metabolic changes, long before the bariatric or weight loss effects occur, leadi ... Full text Link to item Cite

Preoperative weight gain does not predict failure of weight loss or co-morbidity resolution of laparoscopic Roux-en-Y gastric bypass for morbid obesity.

Journal article Surg Obes Relat Dis · 2008 BACKGROUND: Success with preoperative weight loss (PWL) is often mandated by the bariatric team to assess patient compliance and has been suggested to correlate with improved postoperative weight loss outcomes. METHODS: We performed a retrospective analysi ... Full text Link to item Cite

New developments in surgery: Natural Orifice Transluminal Endoscopic Surgery (NOTES).

Journal article Arch Surg · March 2007 Natural orifice transluminal endoscopic surgery refers to the method of accessing the abdominal cavity through a natural orifice under endoscopic visualization. Since its introduction in 2004, numerous reports have been published describing different surgi ... Full text Link to item Cite

Expectant management of the asymptomatic gallbladder at Roux-en-Y gastric bypass.

Journal article Surg Obes Relat Dis · 2007 BACKGROUND: Because of the claim that about one third of patients develop gallstones within 6 months of Roux-en-Y gastric bypass (RYGB), many have recommended preoperative ultrasonography for all patients and/or prophylactic cholecystectomy (CCY), or ursod ... Full text Link to item Cite

Obesity surgery mortality risk score: proposal for a clinically useful score to predict mortality risk in patients undergoing gastric bypass.

Journal article Surg Obes Relat Dis · 2007 BACKGROUND: Currently, no clinically useful scoring system is available to stratify the mortality risk for patients undergoing gastric bypass (GBP). We propose the obesity surgery mortality risk score as a clinically useful score system to predict the mort ... Full text Link to item Cite

Leiomyosarcoma of scrotum--case report and review of literature.

Journal article Urology · February 2006 Leiomyosarcoma of the scrotum is a rare tumor. Cutaneous and subcutaneous leiomyosarcomas constitute the two subtypes. We report a case of cutaneous leiomyosarcoma of the scrotum in a 73-year-old man. Cutaneous leiomyosarcoma arises from the smooth muscle ... Full text Link to item Cite