Gastroparesis can be a debilitating condition that affects patient quality of life. Over the past two decades, there has been a dramatic increase in hospital admissions and health care expenses due to gastroparesis and its complications . This chapter will focus on malnutrition and the options for enteral feeding techniques that with the aim of maximizing nutrition and improving symptoms.
When oral diet is not enough
The risk of malnutrition in gastroparesis is associated with its severity. Protracted nausea and vomiting not only limits nutritional intake but can also lead to food aversion furthering the detrimental cycle that leads to decreased caloric consumption, and essential vitamin and mineral deficiency. Dietary modification with consultation from a nutritional specialist should always be the first step in managing patients with gastroparesis. Patients should be counseled to use a low-fat, low-fiber diet, or a microparticle diet . When gastroparesis is severe enough to prevent adequate intake of the recommended diet, there can be compromise of weight, nutritional status and hydration. A study from the NIH Gastroparesis Consortium showed that out of 304 patients on an oral diet, 64% had a reported caloric-deficient diet defined as less than 60% of total energy requirements (TER). These patients were also deficient in vitamins A, B6, C, K, iron, potassium and zinc .
When to consider enteral nutrition
Unsuccessful maintenance of adequate nutrition with oral intake should lead to the consideration of enteral feeding to prevent malnutrition, as support while treatments for gastroparesis are being implemented. The Academy of Nutrition and Dietetics (AND) and American Society for Parenteral and Enteral Nutrition (ASPEN) published guidelines to define malnutrition, irrespective of underlying disease. AND/ASPN define malnutrition as at least 2 or more of the following: (1) insufficient energy intake; (2) weight loss, (3) loss of muscle mass; (4) loss of subcutaneous fat; (5) localized or generalized fluid accumulation that may mask weight loss; (6) diminished functional status. Patients who show signs of malnutrition according to these criteria have higher 30-day readmission rates, increased in-hospital mortality, with survivors showing increased hospital length of stay and reduced likelihood of shorter times to live discharge. These are mostly based on retrospective studies . It is important to note that laboratory values such as albumin and prealbumin are not reliable markers for malnutrition as they do not accurately reflect hepatic protein synthesis. They may also be affected by other factors such as clinical condition, the disease state, hydration status, the acute phase response, albumin leakage out of the intravascular space, and severe zinc deficiency .
In patients who cannot maintain normal body weight with oral nutrition, other means of support must be considered. Failure to reach or maintain a target weight determined with nutrition service consultation should be the trigger to offer enteral nutrition . Enteral feeding must also be considered in patients unable to sustain oral intake for nutrition, hydration or medication who have lost 5–10% of usual body weight over 3–6 months or have had numerous admissions for hypovolemia, diabetic ketoacidosis and electrolyte abnormalities due to nausea and vomiting. Such patients often have a severely diminished quality of life . Determination of the type and duration of enteral nutrition should be a multidisciplinary approach involving registered dieticians, gastroenterologists and primary care providers to optimize nutrition, weight gain and close outpatient monitoring.
Logistics of tube feeding—setting up home feeds
When the decision is made to proceed with GJ or J tube insertion, usually during a hospital admission, the logistics of feeding need to be addressed in advance of tube placement. That includes ensuring that feeds, as well as the means to deliver them (gravity, syringe or pump) and training of the patient and caregivers will be in place upon discharge. Homecare services will need to be involved in training and supervision of the initial feeding setup at home, and can be instrumental in determining insurance coverage options and eligibility. When available, multidisciplinary home enteral nutrition programs (HENs) may provide better outcomes for these patients . Criteria proposed for use of home enteral nutrition include inability to maintain oral nutrition, with recommendation of a feeding tube to be used for at least 4 weeks, demonstration of tolerance of enteral feeds, clinical stability, acceptance of the tube by the patient and caregivers, and a safe home environment with clean water and electricity . Insurance coverage for feeds, equipment and (if necessary) homecare will vary across jurisdictions and insurance providers. In the US, the Centers for Medicare and Medicaid has listed criteria for coverage of enteral therapy (National Coverage Determination [NCD] for Enteral and Parenteral Therapy [180.2]) ( www.cms.gov/medicare-coverage-database/details/ncd-details.aspx?NCDId=24 ).
The criteria which need to be met for Medicare coverate of enteral feeds and supplies have been discussed in detail by Newton and Barnadas :
Presence of a “permanent” disorder (>3 months or indefinite duration) of structures that allow food to reach the small bowel, or an impairment of the small bowel that prevents digestion and absorption. Gastroparesis is a recognized disorder for this purpose. Supplemental oral intake may be used, but the majority of nutrition needs to be delivered by tube.
Failure to maintain adequate nutrition with oral dietary adjustments or supplements. Typically this will require 750–2000 calories per day—registered dietician input is key here.
Liquid feeds must enter a tube to reach the stomach or small bowel—oral feeding formulas will not be covered.
If a special formula or pump is being ordered, medical documentation supporting the request(s) is required. Pumps are preferable for enteral feeding, as they can allow for easy titration of feed rates. Documentation of need for jejunal or small bowel feeding is one of the listed criteria for approval of a pump.
Unfortunately in US jurisdictions, there may not be uniformity in these criteria, or in the process to determine eligibility, across private and state run Medicaid plans. Some plans will not allow orders from providers who practice in neighboring states .
Methods for delivering enteral nutrition
Once it has been determined that enteral feeding is indicated, the type and route need to be individualized based upon length of intended therapy, need for gastric decompression and feasibility of procedure to confirm placement. A current recommendation from the American Society for Gastrointestinal Endoscopy (ASGE) advocates the use of jejunal feeds instead of direct gastric or duodenal feeding in patients with severe gastroparesis although this was based on low quality, GRADE II evidence given the lack of adequate clinical studies . It has been reported that jejunal feeds may improve symptoms and reduce hospitalizations in some patients with severe diabetic gastroparesis; however, this inference was from a small, retrospective study of surgical jejunostomy and although overall health was significantly improved, symptoms and nutritional status were not . Feeds are typically delivered by feeding pump, and sometimes gravity feeding, in an intermittent or continuous manner, although syringe bolus can also be used . The general technique is to gradually increase tube feeding rates up to levels which ensure adequate nutrition, subject to patient tolerance of feeds.
A summary of the types of enteric feeding is found in Table 29.1 .
|Type of access||Technique for placement||Purpose||Pros||Cons|
|Short term access (4–6 wk)|
|Nasojejunal (NJ)||Endoscopy (drag and pull, over the guidewire)||Temporary feeding|
|Radiology (over the guidewire)|
|Long term access (4–6 wk)|
|Gastrojejunostomy (GJ)||Percutaneous (endoscopy- PEG; radiology- RPG-J)|
|Surgery (laparoscopy-PLAG; open)|
|Direct jejunal access||Percutaneous (endoscopy- DPEJ; radiology- PEJ)|
|Surgery (laparoscopy; open)|
Short term enteral nutrition: nasojejunal access
A trial of nasojejunal (NJ) feeding has been considered a first step before proceeding with percutaneous enteric feeding in gastroparesis. Small bowel dysmotility can occur in patients with gastroparesis and thus a trial of enteric feed tolerance can be a useful way to assess the efficacy of a percutaneous technique before embarking on an invasive procedure. NJ tubes are recommended to stay in place for not more than 4 weeks due to increased risk of nasal trauma after this time . Patient tolerance is generally good, but some cannot tolerate any nasal tube, even a for a short time due to nasopharyngeal discomfort. Due to its visibility, some patients find presence of the tube psychologically stressful . Although NJ feeding is largely considered a bridge to later percutaneous feeding, one retrospective study reports that almost half of patients in one center experienced both weight gain and symptom improvement solely with a three month trial of NJ feeding, resulting in tube removal and successful transition to an oral diet .
The NJ feeding tube should be placed past the ligament of Treitz to minimize the amount of feed entering the stomach. This usually requires endoscopic placement, or fluoroscopy to confirm placement. Blind insertion into the stomach requires experience with tube positioning and use of prokinetics to allow passage beyond the pylorus, and runs a significant risk of malposition with concomitant pulmonary and pleural morbidity . Endoscopic placement can be achieved with the “drag-and-pull” method with clipping or suturing into the wall of the small intestine. Suture loops tied to the end of the feeding tube can be secured to the mucosa with standard endoscopic clips ( Fig. 29.1 ) . Alternatively, the “over the guidewire” technique uses a guidewire that is first placed into the small intestine through an endoscope channel, followed by removal of the scope leaving the wire in place, and passage of a feeding tube over the wire. The “drag and pull” method can also be used with a guidewire to prevent dislodgment into the stomach with removal of the scope ( Fig. 29.2 ) . The “over-the-guidewire” has a reported initial placement rate in one study of 90–100%, but is technically more cumbersome . If using fluoroscopy alone, successful placement is approximately 90%; however, the lack of ability to anchor the tube to the small bowel may pose a risk for migration . A randomized trial comparing “drag and pull” using clips with endoscopy-guided “over the guidewire” technique showed fewer repeat endoscopies required in the former technique due to higher success in the initial placement (94 vs 74%) .
Although they can be an effective temporary source of nutrition, NJ tubes have three major disadvantages: migration, clogging and lack of palliative gastric decompression. As described above, NJ tubes are notorious for migrating into the stomach with withdrawal of the endoscope or after an episode of vomiting, but are less likely to do so if clipped . Small diameter tubes (12–16 Fr) are prone to frequent clogging. Prevention includes proper training of the patient and nursing personnel to use frequent water irrigation and avoidance of injecting crushed medication tablets through the tube . Both migration and clogging may require repeat procedures to replace and/or reposition the tubes. NJ tubes do typically allow for palliative gastric decompression. To perform adequate gastric relief, a nasogastric tube usually needs to be at least 18 Fr in diameter. Separate NG and NJ tubes in each nostril are not commonly used due to patient discomfort. Currently, dual lumen NG-J tubes are not widely available for temporary NJ feeds and NG decompression but have been evaluated in post-surgical patients in intensive care units . NJ tubes may also result in reflux esophagitis, sinusitis and pressure ulceration . Aspiration and regurgitation may be less likely with jejunal versus duodenal tube placement .
Longer term enteral access: gastrojejunostomy, jejunostomy
If enteral access (for feeding and/or gastric decompression) is required for longer than 1 month, or if a nasojejunal feed trial is well tolerated by the patient, then more durable enteral feeding can be pursued. Placement of feeding tubes can either be gastrojejunal or direct jejunal. Various techniques can be used for placement – percutaneous or surgical. These procedures are performed by gastroenterologists, surgeons and radiologists. To date, studies comparing feeding tube placement types and techniques have not been performed. Each has its own advantages and disadvantages, and the chosen approach and technique must be individualized based on symptoms, institutional expertise and medical comorbidities.
A feeding gastrojejunostomy is a feeding pathway that extends from the abdominal wall, through the stomach and into the proximal small bowel. Gastrojejunostomy is one option to provide nutrition for severe gastroparesis recommended by the American society of Gastrointestinal Endoscopy (ASGE) . It has the added capability of allowing gastric venting for symptom alleviation. The role of gastrostomy for palliative decompression in patients with gastroparesis is not universally accepted . Although venting gastrostomy tubes may help some patients with gastroparesis who complain of abdominal distention, vomiting and bloating, there are no randomized trials proving efficacy and if vented fluids are not replaced, these tubes can cause electrolyte imbalances (especially hypokalemia) and dehydration . Most data supporting their benefit are retrospective studies on gastric decompression in patients with malignant small bowel obstruction .
There are many commercially available products but the basic gastrojejunostomy technique involves a 9 or 12 French jejunal feeding tube passed through an existing larger bore venting gastric tube (at least 18 French) that is then guided into the small bowel past the ligament of Treitz ( Fig. 29.3 ) . Percutaneous placement can be performed by an endoscopist or interventional radiologist under moderate or conscious sedation; laparoscopic placement by a surgeon requires general surgical anesthesia in an operating suite.
Percutaneous endoscopic gastrojejunostomy (PEG-J) requires endoscopic transillumination from the gastric side and external finger indentation to confirm safe placement. If transillumination or indentation is not visualized, then the procedure should not continue for fear of perforating overlying colon, small bowel or liver. The procedure usually involves two proceduralists: one to hold the endoscope and the other to puncture the stomach to create the ostomy. The next steps involve the “push” method where the feeding tube is pushed through the ostomy site between endoscopically placed T-fasteners which adhere the stomach to the abdominal wall, or the “pull” method where the tube is inserted through the mouth over a wire and pulled through the ostomy; both techniques are equally effective . Once the gastrostomy is created, then the jejunal limb of the feeding tube is passed through the PEG stoma and either pulled into the jejunum with the endoscope or less commonly threaded over an endoscopically placed guidewire passed into the proximal jejunum. Placement is usually secured by clipping a suture loop on the distal end of the tube to the jejunal mucosa. After PEG-J placement, gastric ventilation can be performed immediately and although timing for jejunal feedings post procedure has not been established, most proceduralists will wait 3–4 hours after placement, although it appears that earlier commencement at 1–3 hours may be safe in PEG tubes (this has not been confirmed in J tube feeding) .
Radiologically placed gastrojejunostomy (RPG-J) uses x-ray and fluoroscopy to ensure successful percutaneous gastric access. First, a nasogastric tube is placed to insufflate the stomach. Then the stomach is fixed to the abdominal wall with three gastropexy T-fasteners, followed by puncturing through the stomach. Successive dilations are then performed to the size of the desired feeding tube, which is then inserted over guidewire into the small intestine and confirmed with fluoroscopy . Overall, this technique is effective and safe .
Laparoscopic gastric access for gastrojejunostomy
Although rare for both PEG-J and RPG-J placement to be unsuccessful due to failure to obtain a safe percutaneous window, another option is percutaneous laparoscopic assisted gastrostomy (PLAG). This is a surgical procedure that requires general anesthesia. First, the peritoneum is inflated with CO2 via a Veress needle. Then, two 5 mm trocars are placed: one for a camera, the other for a working channel. The stomach is then inflated with CO 2 via the same Veress needle and three gastropexy T-fasteners with sutures are inserted into the stomach. The stomach is then fixated to the abdominal wall after traction of the sutures. An incision is made between the three anchors, and the GJ feeding tube is inserted into the stomach and guided past the ligament of Treitz ( Figs. 29.4–29.9 ). PLAG placement is more invasive than that of PEG or RPG, however, it has been shown to be a successful alternative if the latter two options are not possible, with lower morbidity than conventional surgical gastrotomy .