BB&T Senior

NEW ORLEANS — Despite a massive oil spill threatening the Gulf Coast, Digestive Disease Week 2010 kicked off without a hitch, drawing roughly 15,000 GI researchers and 2,000 to 3,000 exhibitors to the Big Easy.

As DDW attendees arrived in New Orleans for the annual meeting of four organizations – the American Association for the Study of Liver Diseases (Alexandria, Virginia), the American Gastroenterological Association (Bethesda, Maryland), the American Society for Gastrointestinal Endoscopy (Oak Brook, Illinois) and the Society for Surgery of the Alimentary Tract (Beverly, Massachusetts) – obesity emerged as one of the hot topics in recent GI research.

A study suggests that surgeons planning to operate on heavier patients should expect the patient to be more likely to experience complications, surgical site infections, and/or require a reoperation than smaller patients.

“Being overweight or obese is known to impact a patient's ability to recover from surgery,“ David Berger, MD, a professor of surgery at the Baylor College of Medicine (BCM; Houston), told reporters during a press conference in April previewing the DDW meeting. “But our study indicates abdominal fat is particularly relevant to abdominal surgical outcomes.“

Berger's co-author, Courtney Balentine, MD, a fellow in surgical research at BCM, presented the findings to DDW attendees.

Traditionally, obesity has been measured by body mass index (BMI), a measure of weight relative to height. But Berger, who also is an operative care line executive at the Michael E. DeBakey VA Medical Center (Houston), says BMI is an indirect measure of obesity. “We felt that BMI was not the best predictor of obesity because it doesn't tell us anything about where the fat is distributed in obese individuals,“ he said.

Berger and Balentine sought to find out if a patient's waist circumference could serve as a better indicator than BMI in determining whether a patient would have difficulty recovering from surgery.

“We felt that having more fat located around their waist where abdominal surgery was being performed, would be more important for predicting complications than fat which may be located elsewhere such as on the arms, legs or posterior,“ Berger said.

The study of 150 patients who underwent rectal cancer surgery found heavier patients were twice as likely to experience complications than patients with a smaller waist circumference. Patients with a waist of 45 inches or more were three times more likely to experience surgical site infections and twice as likely to require reoperation after their initial surgery.

“This study provides important insight for surgeons planning to operate on a patient with heavy midline fat distribution,“ Berger said. “Necessary surgical procedures cannot be avoided, but surgeons may want to consider altering antibiotic dosages in order to better fight infection.“

While past studies of BMI and surgical infections have had inconsistent findings, the researchers say this study is the first using waist circumference as a predictor of short-term surgical complications.

Berger said that even after he and his colleagues adjusted for other factors which contribute to the risk of complications, they still saw that the odds of infection doubled each time the waist circumference increased by 10 centimeters, or about 4 inches, and the odds of having any complication increased by 60%. BMI was not a good predictor of complication, he said.

During April's press conference previewing the research, Lawrence Friedman, council chair of DDW 2010, asked Berger if the study results are applicable to other types of abdominal surgery or even non-abdominal surgery.

“I think it's probably relevant for other major abdominal surgeries where you have a significant incidence of wound infection,“ Berger said. “For other surgeries, it's probably not as relevant.“

He added that wound infection is a relevant factor. “We saw an increase in wound infections from 14% in the thinnest patients to 46% in the heaviest patients,“ Berger said, noting that, traditionally, antibiotic dosage has not been varied in the perioperative period depending on body weight. “So this may be an intervention that can be . . . used to try to reduce the infections in these patients.“

There are some other measures that have been shown to potentially decrease surgical site infection, according to Berger, such as maintaining high oxygen content and also maintaining the proper temperature. “Those have not been shown yet to be important in reducing infections in obese patients, but certainly may be a logical step to make sure those things are implemented as well,“ he said.

While a couple of small studies have looked at obese patients and show a benefit to adjusting antibiotics, Berger says there is no randomized prospective trials looking at obese patients and tailoring antibiotics based on the waist circumference or the fat of the patients.

Another interesting obesity-related study presented Monday morning at DDW raised concern that performance metrics ignore differences in complication rates and cost for obese patients undergoing two common general surgical procedures.

New Medicare and Medicaid payment policies are intended to reward physicians for positive patient outcomes while cutting costs, but according to new research from the Johns Hopkins University School of Medicine (Baltimore) such policies may actually provide financial incentives for doctors to discriminate against patients.

The researchers noted that pay-for-performance policies have grown in popularity throughout the last few years and are increasingly used to measure the quality of medical care. The premise behind the mechanism is to financially reward hospitals and doctors for good outcomes and punish for poor patient outcomes by adjusting reimbursement by 1% to 2% if an infection occurs within 30 days of surgery. According to Martin Makary, MD, a surgeon and associate professor of public health at the Johns Hopkins School of Medicine, such payment structures fail to account for patient factors that are out of the control of doctors yet influence outcomes, the most common being obesity, which can double a patient's chance of infection.

Studying national insurance claims of 36,483 patients who had undergone one of two common general surgical procedures, Makary, senior author of the study, found that obese patients undergoing appendectomy were 25% more likely to experience complications, and patients undergoing cholecystetomy were 7% more likely to have complications. In addition, Makary found that the cost of providing such care was higher for obese patients: the median total inpatient costs for obese patients after a basic gallbladder removal were $2,978 higher and $1,600 higher for appendectomy.

Because obesity rates are higher in minority populations – black women have a 50% incidence of being overweight compared to 18% for white men – Makary expressed concern for the discrimination implications under such payment structures. “What sounds good in theory turns out in reality to punish doctors who take care of more high-risk patients, and actually financially incentivizes discrimination,“ Makary said.

He says standardized outcomes accounting for patient factors would eliminate the unintended incentives to discriminate. The National Surgical Quality Improvement Program is a doctor-initiated program that has developed such outcome measures, he noted.

Another obesity-related study presented at the meeting found intragastric saline-filled balloons to be a safe, effective, and minimally invasive weight-loss treatment for pre-obese and obese patients, and may offer an alternative weight-loss treatment option for patients who may not be eligible for gastric bypass to reduce the morbidity and mortality associated with obesity.

According to researchers at Gastroendo Medical Group (Brazil), intragastric balloon procedure designs have progressed to eliminate many of the complications initially associated with the procedure, namely a smooth, seamless balloon constructed from a long-lasting material with a low ulcerogenic (tending to develop into ulcers) and obstruction potential, as well as the ability to adjust the balloon size and to fill the balloon with fluid instead of air. While this procedure has been employed internationally and in the U.S. for some time, this study may help establish expanded indications for intragastric balloon procedures including pre-obese patients, the authors noted.

Over a 15 month period, 81 patients completed the study using the intragastric balloon. Patients were divided along BMIs in four grades: pre-obese (BMI < 30), obesity grade 1 (BMI 30-34.9), obesity grade 2 (BMI 35-39.9) and obesity grade 3 (BMI = 40). Prior to the procedure, each patient had failed to respond to previous clinical treatment for weight loss including a calorie-restricted diet, physical activity, behavior modification and pharmacotherapy.

Researchers, led by Paula Elia, MD, at Gastroendo, performed the placement and subsequent removal of the balloon under propofol sedation. Balloons were smoothly inserted into the stomach by traction under direct endoscopy vision and were positioned in the upper stomach position. The balloon was filled with a saline solution and methylene blue, to help in locating and removal of the balloon. Patients were followed for five to seven months in a multidisciplinary clinical setting, including a gastroenterologist, endocrinologist, nutritionist, psychologist and psychiatrist. The balloon was removed after the five to seven month observation.

Participants across all obesity grades experienced significant weight loss, losing an average of 9. 18% of initial weight. Patients with an obesity grade 3 experienced a more significant average weight loss of 12.2% of initial weight.

Elia cautioned that the intragastric balloon and intragastric balloon procedures are not a miracle weight loss method; after the balloon is extracted, weight loss maintenance depends exclusively on a combination of a calorie-restricted diet, physical activity and behavior modification.

EUS comparative to surgery for pancreatic pseudocysts

Attempting to maneuver the halls of the Earnest N. Morial Convention Center is a bit like playing the classic arcade game Frogger – only instead of dodging trucks and alligators the object is to avoid the thousands of other DDW attendees navigating between sessions.

When they weren't zigzagging through the crowded hallways, however, gastroenterology specialists presented findings that highlighted surgery vs. chemotherapy in patients diagnosed with pancreatic cancer. One study of particular interest suggests that endoscopic ultrasound (EUS) is as effective as surgery in treating pancreatic pseudocysts while also being less expensive, less invasive and less painful than surgery.

Pancreatic pseudocysts develop in about 10% of patients with pancreatitis, a painful condition in which the pancreas is inflamed, causing abdominal pain, nausea and vomiting. Pseudocysts can block the intestines or stomach preventing food from being digested, and, because of their size, they increase pressure in the abdomen, causing pain, according to the study abstract.

“The way that we manage these patients usually is by surgery,“ Shyam Varadarajulu, MD, from the University of Alabama at Birmingham School of Medicine, told reporters during a press conference. He also presented his study to other DDW attendees.

With the surgical approach, the pseudocyst is opened and attached to the stomach so that the fluid can be drained into the stomach. Varadarajulu said the post-operative hospital stay is roughly five days, and costs $22,475.

EUS is a new technology that, according to the study, represents an alternative to surgery by using an ultrasound at the tip of an endoscope which is passed into the stomach and is used to locate the pseudocyst on the outside of the stomach, Varadarajulu said. Through a small incision and the use of a stent, the pseudocyst can be drained into the stomach without the incision on the skin's surface, which is required with surgery, Varadarajulu explained.

EUS typically results in a two-day hospital stay at the most, and often the patient actually goes home the same day. This less invasive approach is also quite a bit cheaper, Varadarajulu noted, at just $8,195. Previous research has shown that pseudocysts could be managed by EUS, he said, but the treatment outcomes compared to surgery was not known.

Varadarajulu and his fellow researchers studied 36 patients over a 30-month period that had undergone EUS to treat pancreatic pseudocysts. It is important to know, he said, that EUS is not always a treatment option, depending on where the pseudocyst is located in the pancreas because sometimes it simply can't be reached with an endoscopic ultrasound.

“Our results show the effectiveness of EUS in treating pseudocysts and indicate that an investment in the development of better devices for performing the procedure would be worthwhile,“ Varadarajulu said.

Another study of interest shows a potential link between pancreatic cancer and inflammatory bowel disease (IBD), a disease that afflicts one in 500 Americans, according to the study abstract.

Investigators had previously observed that pancreatic cancer seemed to occur more frequently in patients and family members of patients with IBD, so researchers at the University of Utah (Salt Lake City) examined data from the National Cancer Institute's Surveillance Epidemiology and End Results (SEER) database in conjunction with the Utah cancer registry. They looked at a retrospective, population-based cohort study of 2,877 adult patients over a 10-year period.

Jason Schwartz, MD, an assistant professor of surgery at the University of Utah, told reporters that the results were “somewhat startling and somewhat unexpected.“ He said the findings revealed that patients with IBD are three times more likely than the general population to develop pancreatic cancer. For women with ulcerative colitis, a form of IBD, that risk bumps up to four times more likely to develop the cancer than the general population. And for men with ulcerative colitis, the study showed up to a six-fold increased risk of pancreatic cancer.

According to the abstract, investigators say the study results suggest a possible hereditary link between IBD and pancreatic neoplasia. They added that because few risk factors have been identified for the development of pancreatic malignancy – making current screening attempts mostly ineffectual – these results have potential implications for the early identification of patients with pancreatic cancer and may translate to improvements in survival similar to other forms of cancer where early screening has been employed successfully.

“Given a diagnosis of [IBD], specialized populations may benefit from efforts aimed at early detection where surgical intervention may offer a hope of long-term survival,“ Schwartz said. “The survival rate for this cancer is currently very low, mostly because the tumor is discovered extremely late in its course.“

According to the study, previous reports have examined the association between IBD and various other malignancies, but this study is the first to examine standardized incidence rates of IBD and pancreatic cancer, which is an estimate of the occurrence of cancer in a population relative to a larger comparison population designated as “normal“ or “average.“

“Patients often ask their physicians 'what did I do to cause this?'“ said Craig Fischer, MD, of The Methodist Hospital (Houston) and the moderator of a press conference on the study. He said he anticipates a significant number of calls from his patients with ulcerative colitis, particularly men with the disease, soon after news of these study results are reported in the media.

Schwartz cautioned, however, that people should not conclude that all patients with IBD will develop pancreatic cancer. More studies are needed, he says, to examine whether an increased risk of pancreatic cancer exists in extended family pedigrees of patients with IBD. If an increased predilection for pancreatic cancer exists in these family members, future studies will also focus on identification of the mode of inheritance as well as attempts to identify “susceptibility genes“ that put patients at increased risk. He added that other studies may examine the utility of various screening modalities in susceptible populations.

“It's too early to make any screening recommendations,“ for IBD patients, Schwartz said.

Fischer pointed out that physicians treating pancreatic cancer patients are eager for a way to identify groups of people who might be considered high risk for developing the cancer, so that hopefully survival rates of the disease will ultimately be improved through earlier diagnoses.

“We don't want to look for a needle in the hay stack,“ Fischer said. “Give us that needle.“

Unfortunately, Schwartz reiterated his earlier point when MDD asked him what advice he might be able to offer for IBD patients – particularly those with ulcerative colitis who are, according to the study, at a four- to six-fold increased risk for pancreatic cancer.

“I don't have a good answer for you. I think it's too early [to offer such advice],“ Schwartz said.

'Electronic nose' can distinguish bowel disease

Gastroenterologists may soon be able to detect the existence of inflammatory bowel disease (IBD) by using an “electronic nose,“ according to Ramesh Arasaradnam, MD, gastroenterology consultant and senior lecturer at the University of Warwick (Coventry, UK).

Arasaradnam presented findings from his study, which used what is called a Cyrano A320 detection device, to DDW attendees. DDW is considered to be the largest international gathering of physicians and researchers in the field of gastroenterology, hepatology, endoscopy and gastrointestinal surgery.

“This gives a new insight into the nature of IBD, and in time may allow us to identify the disease at an earlier, more treatable stage,“ said Arasaradnam, the study's lead investigator. “This could prevent patients from having to undergo invasive procedures.“ He added that the test results may be able to help clinicians select the most appropriate treatment.

The device is based on the principal of the human nose, Arasaradnam told reporters during a DDW press conference highlighting technology breakthroughs for diagnosing and treating disease.

The device is designed to recognize the bio-odorant signature characteristic of the condition, Arasaradnam explained. For the study, he and his fellow investigators collected urine samples from healthy volunteers as well as those with ulcerative colitis and Crohn's disease. Then, five patients from each cohort were analyzed using a Cryano A320 detection device, which uses chemical sensors that create a “fingerprint“ of the total chemical composition of a sample. Each was sampled for 30 seconds and purged for 30 additional seconds in laboratory air, and then the differential response between the sample and background air was used to analyze the specimen. The result was that the device was able to distinguish between disease groups based on their gaseous profile from urine samples.

While it might seem to make more sense to use fecal samples rather than urine samples for this study, Arasaradnam said fecal samples are more difficult to obtain for a variety of reasons, including the fact that many patients are simply too embarrassed to produce a fecal sample for testing.

The technology is “very much in the early stages,“ Arasaradnam cautioned, “but it shows great promise in terms of early diagnosis.“

In addition to detecting IBD, Arasaradnam told BB&T the electronic nose can distinguish ulcerative colitis from Crohn's disease, and these in turn from “normal“ patients. For ulcerative colitis patients, the electronic nose is designed to differentiate between those who have and had not had treatment.

For example, if a patient who had ulcerative colitis but has undergone surgery to remove their colon to treat the disease provided a urine sample, the device would be able to tell them whether or not the disease was gone or if there was still inflammation in the portion of the bowel that remained.

The researchers hope to develop the tool to be able to distinguish where patients are on the pathway of treatment. Additionally, according to the abstract, they hope to devolve the instrument into a portable device that can be carried or used by anyone in a clinical setting, give results that are easy to interpret, does not require very specialized or high power computers, and is affordable. Currently the developers of the device, at the University of Warwick, are using a prototype that will need to be refined to be used on a regular basis, the researchers noted.

Arasaradnam also acknowledged during a conversation with BB&T after the press conference, that doctors are increasingly recognizing what is known as “phantom colon.“ Just like amputees have been known to experience “phantom leg“ – the sensation (often a painful sensation) that an amputated leg is still attached to the body – patients who have had surgery to remove all or a portion of their colon to treat ulcerative colitis often feel as if the organ is still there.

Doctors never used to listen to patients when they complained of this sensation, Arasaradnam admitted, but he says gastroenterologists are increasingly beginning to pay attention and acknowledge that phantom colon may actually exist.

“I just love the fact that the device name is Cyrano A320,“ chuckled Kenneth Wang, MD, of the Mayo Clinic College of Medicine (Rochester, Minnesota), when Arasaradnam finished talking about his study. Wang moderated the technology-focused press conference.

“Advancements in technology are changing the face of medicine daily,“ Wang said. “With every development we are able to diagnose and treat illness more effectively and at an earlier stage.“

Endoscopic stenting cheaper than surgical GJ

Physicians now have two treatment options for the relief of malignant gastric outlet obstruction, and a new study presented at the DDW meeting suggests that one option is significantly cheaper, with shorter hospital stays, than the other.

Shyam Varadarajulu, MD, associate professor of medicine in the Division of Gastroenterology & Hepatology at the University of Alabama at Birmingham School of Medicine presented the study, which he said demonstrates that endoscopic duodenal stenting is associated with lower costs and shorter hospital stays than surgical gastrojejunostomy (GJ) for the relief of malignant gastric outlet obstruction. Surgical GJ is considered the current gold standard for this problem.

Varadarajulu told DDW attendees that the median cost per hospitalization ($15,279 vs. 27,790) and the median length of hospital stay (LOS; 8 days vs. 16 days) were significantly less for endoscopic stenting than surgical GJ. In addition, Varadarajulu noted that endoscopic stenting was more commonly performed at urban vs. rural, and teaching vs. non-teaching hospitals. The study was conducted using the WallFlex Duodenal stent from Boston Scientific (Natick, Massachusetts).

Varadarajulu also presented similar findings at DDW that suggests that endoscopic ultrasound is as effective as surgery in treating pancreatic pseudocysts while also being less expensive, less invasive and less painful than surgery.

This study also was one of several studies presented at DDW that examined the diagnostic and therapeutic utility of Boston Scientific products. Other studies evaluated the use of the company's SpyGlass Direct Visualization system, Radial Jaw 4 biopsy forceps, along with several other devices in the company's endoscopy portfolio.

“We take our leadership in the stent space very seriously,“ David Pierce, VP of marketing for Boston Scientific Endoscopy, told BB&T during an interview at DDW. He emphasized the importance of presenting clinical studies backing up the company's devices. “It's not just bringing new technology to the market, it's bringing the clinical proof [that the technology works safely and effectively],“ Pierce said.

According to Boston Scientific, Endoscopic stenting is increasingly performed for the relief of malignant gastric outlet obstruction – a late complication of duodenal, pancreatic, gallbladder, biliary tract and small intestine cancers. An analysis of the Medicare database was conducted to identify hospitalizations for endoscopic stenting and surgical GJ for malignant gastric outlet obstruction between 2006 and 2008. The database included 423 endoscopic stenting and 352 surgical GJ hospitalizations that met the study inclusion criteria.

The study also evaluated clinical outcomes for 29 patients who underwent endoscopic stenting and 75 patients who underwent surgical GJ at the University of Alabama at Birmingham Hospital, and compared rates of technical and treatment success, post-procedure LOS and delayed complications. While both treatment methods were technically successful and relieved the obstruction, the researchers said, the median post-procedure LOS was significantly shorter for endoscopic stenting than surgical GJ (1.5 vs. 10.7 days). There was no difference in rates of delayed complications, according to the study.

Boston Scientific said its WallFlex Duodenal stent was used in many of the stenting patients in the study. It is a large diameter, radiopaque, flexible, self-expanding metal stent designed to help maintain luminal patency in patients with gastroduodenal obstructions. The stent has looped ends and incorporates a flared design intended to reduce the risk of mitigration, the company said. The low profile, reconstrainable delivery system features a tapered tip to support access and radiopaque markers to aid in placement accuracy, Boston Scientific added.

According to the company, palliation of symptoms is the primary treatment goal for patients suffering from malignant gastric outlet obstruction, and this study shows that stenting provides a less-invasive treatment option that is as effective as surgery but at a lower hospital cost and shorter stay.

The WallFlex Duodenal stent was one of many devices available for demonstration and displayed at Boston Scientific's massive DDW booth at the Earnest N. Morial Convention Center. Other products the company chose to spotlight during the meeting included:

• The Twister rotatable polyp retrieval device is now available and was designed to facilitate polyp and foreign body retrieval with a fully rotatable basket. The Twister rounds out the company's tissue acquisition family of forceps and snare products, Boston Sci said. BB&T teasingly asked Pierce at DDW if the Twister device was anything like the game. “It's as easy as the game,“ he quipped. In addition to being easy to use, the product offers some technical advantages over previous technology, Pierce said. “It's been a nice product for us and it fills a gap that we had in our portfolio. We are excited about the success it's had for us.“

• The SypGlass direct visualization system, designed to provide diagnostic and therapeutic applications under direct visualization throughout the pancreatico-biliary system, including the hepatic ducts, improving on traditional, long-standing cholangioscopy systems, according to the company. At DDW, Jeffrey Laczek, MD, presented a multi-center study featuring the SpyGlass system. The study suggests that cholangioscope image quality is not different when immersed in normal saline, contrast or a mixture of normal saline and contrast, and that endoscopists should use intraductal contrast prior to cholangioscopy if needed for lesion localization. Another study featuring the same device found that the system is a useful diagnostic tool when dealing with radiologically evident biliary strictures, and that tissue sampling under visual control is technically feasible and clinically safe, Boston Sci said.

• The WallFlex Biliary RX fully covered and partially covered stents have recently received FDA clearance, the company noted, and are indicated for the palliative treatment of biliary strictures produced by malignant neoplasms. According to Boston Scientific, this stent offers improvements over its WallStent Biliary Endoprosthesis with greater flexibility, enhanced full length radiopacity and looped and flared stent ends that may reduce the risk of tissue trauma and stent migration.

• The WallFlex Esophogeal fully covered and partially covered stents are part of Boston Sci's latest generation of self expanding metal stents, the company said. The WallFlex fully covered stent was cleared by FDA in November along with CE mark approval for the treatment of malignant esophageal strictures caused by tumors in patients with resectable and non-resectable esophageal cancer. Its Permalume covering is designed to help reduce food impaction, prevent tumor ingrowth, and seal concurrent esophageal anatomy such as peristalsis and strictures.