Enteric tube placement for gastroparesis: Gastrostomy, gastrojejunostomy and jejunostomy

Introduction

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.

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 .

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.

Gastrojejunal approach

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.