Surgical management of gastroparesis

Introduction

Gastroparesis (GP) is a disorder of delayed gastric emptying in the absence of mechanical obstruction that manifests with abdominal pain, nausea/vomiting, bloating and early satiety. Total or subtotal gastrectomy is indicated only as the final step in the GP subset of patients (<5%) whose vomiting has not responded to all medical therapies including PP and GES. However, extensive gastric resection surgery has complications, including long-term nutritional challenges, limiting its application . In those patients refractory to standard initial medical therapy affecting 30% of patients, then combining PP with GES is one consideration as the next best choice and approach currently recommended, with the main goal being to accelerate gastric emptying as well as addressing continuing nausea . Tailored approaches with staged care ranging from initial enteral support to simultaneous GES/PP are the preferred options for organ-sparing surgery in this population that suffers from chronic ongoing symptoms as well as malnutrition .

Enteral access: decompression and feeding

Enteral access is the first stage in the treatment paradigm for rescuing patients from chronic malnutrition and recurring hospital admissions (please also refer to Chapter 29 for definitive information on use of enteric tube placement in patients with gastroparesis).

Gastrostomy tubes

These tubes can prevent symptoms of nausea and vomiting in GP and reduce hospitalization rates by a factor of 5 during the year after placement by venting the stomach and allowing drainage of gastric contents . Venting functions can be complicated by electrolyte imbalances and malnutrition. Per-endoscopic gastrostomy (PEG) with jejunostomy extension (PEG-J) can provide dual drainage and feeding functions. Complications include migration of the J-tube extension back into the stomach and pyloric obstruction related to the tube also sharing the pyloric canal lumen . Gastrostomy tubes can be placed endoscopically or surgically using a wide variety of techniques listed in order below of complexity and feasibility:

1.

Gastrostomy-laparotomy technique. This is most commonly combined with concomitant procedures or in cases where inflammatory conditions or repeat surgeries prevent safe endoscopic or laparoscopy-assisted access.
2.

PEG-pull technique. First introduced by Ponsky in 1980, this technique utilizes the gastroscope for insufflation of the stomach to allow palpation and entry of a needle percutaneously using “safe tract” technique to advance a guide wire into the stomach and pull a gastrostomy tube through the mouth and esophagus to exit the anterior stomach .
3.

PEG-push technique. This technique utilizes a stiff wire to advance a gastrostomy that is pushed through the stomach and abdominal wall under endoscopic vision .
4.

PEG-introducer technique. This technique utilizes the Seldinger technique for sheath entry into the stomach with dilation and percutaneous entry of the tube over a wire under endoscopic visualization. The technique is associated with complications from accidental dislodgment, gastrointestinal perforation and tube site infection .
5.

Laparoscopic-Assisted PEG (LA-PEG). This is utilized in those where PEG was not successful secondary to a lack of accurate visualized safe gastric access. Laparoscopy begins with visual access to examine for evidence of inadvertent intestinal injury. The pull PEG technique is then utilized under laparoscopic visualization to ensure safe entry into the stomach .
6.

Laparoscopic gastrostomy. Comparable to open gastrostomy, this is often done in the setting of concomitant procedures. Gastric access is achieved by placing a purse-string suture in the avascular portion of the greater curvature of the body, followed by sharp entry into the stomach using a harmonic scalpel, and insertion of a balloon-tipped feeding catheter. Trans-abdominal sutures may be used to Stamm or suture the stomach to the anterior abdominal wall. Placement of Moss-type feeding tubes or dual lumen tubes are not feasibly accomplished due to a lack the ability to guide the tube through the pylorus using laparoscopy .
7.

Percutaneous transesophageal gastrostomy (PTEG). This technique was first described in 1998 and has not been FDA approved. Placement utilizes ultrasound and fluoroscopic detection of a balloon inflated in the cervical esophagus. A needle is used to access the balloon percutaneously from the neck. The wire and balloon are then advanced into the stomach. Following retraction of the balloon, a feeding catheter is placed percutaneously through the neck into the esophagus and then advanced into the stomach .

Commentary : The indication for this approach is limited to patients who are constantly trying to remove their abdominally-located feeding tube because of psychiatric reasons or in settings of dementia.

Complications of gastrostomy and PEG are low, varying between 5 to 25% and are most commonly attributed to infection. Other complications include tube dislodgment (12.8%), bleeding (1%), aspiration pneumonia, and visceral perforation, the latter mainly determined by the experience of the physician/operator .

Commentary, important advice, and words of caution : Gastrostomy is not a long-term recommendation. If patients cannot tolerate liquid or minimal solid food intake and they actually vomit/regurgitate within 5–20 minutes after intake, then the diagnosis is rumination syndrome and not gastroparesis, and the treatment for rumination syndrome is not gastrostomy. Also the “eating disorder” – anorexia/bulimia is another possibility that can present as immediate post-prandial vomiting, regurgitation, and it is not treated by a gastrostomy. Hence while popular in the pediatric setting, gastrostomy tubes have a very limited, if any, role in managing adults with gastroparesis – unless for a temporary use while resolving a pyloric or small bowel obstruction. In addition, the use of a gastrostomy suction eliminates the stomach from experiencing distention and preparing for the obvious future – oral intake. This tube approach delays and procrastinates appropriate treatment decisions as well as “hiding the diagnosis” by minimizing attempts at instituting oral nutrition intake.

Percutaneous endoscopic gastrostomy with jejunal extension (PEG-J)

This technique consists of an extension to a previously placed PEG tube that extends into the jejunum or can be an “all-in-one” kit with gastric and jejunal ports that allows for simultaneous venting and feeding. Placement involves a guide-wire inserted through an existing PEG which is guided beyond the pylorus. The tube can then be advanced under endoscopic visualization. The jejunal tube can also be pulled using a string at its tip with clipping to the jejunal mucosa . A third technique utilizes a small-caliber endoscope placed thought the pre-existing PEG to guide wire with subsequent tube placement. Complications of this technique include frequent clogging and dislodgment with migration into the stomach .

Commentary and words of caution : This methodology may be acceptable for very short-term settings. However, for maintaining nutrition as well as medication absorption long-term, this is not the correct choice. Patients will vomit and/or retch this PEG/PEJ tube back into the stomach. This results in actually vomiting the enteral formula. There must be frequent x-rays of the abdomen to confirm that the feeding tube is remaining in the jejunum and not migrating proximally into the duodenum or stomach. In addition, there are local skin reactions from the gastric acid contacting the abdominal wall and overall can only be endorsed for very temporary feeding goals (e.g. post-operative). The key requirement here is that there must be an expert in your medical center or community, a very experienced person to perform this procedure when appropriately accompanied by a nutrition support team.

Percutaneous endoscopic jejunostomy (PEJ)

These tubes have advantages of longer latency rates, minimal migration risks, less re-intervention and significant decreased aspiration risks. Placement involves use of either a pediatric colonoscope or a dedicated balloon enteroscope. Similar to PEG placement, the trans-illumination and “safe-track” principles are utilized to insert a large bore needle into the small bowel. A snare grasps the wire placed into the small bowel and the tube is placed using the endoscopic pull technique . Complications occur in 2–6% of these cases to include jejunal volvulus, necrotizing infections, bowel perforations and bleeding. Standard use of percutaneous T-fasteners decreases the risks of jejunal volvulus .

Commentary : The key ingredient here is to have a “go to” expert on your faculty or in your community who does these – has gained all the experience and also knows when this PEJ approach is inappropriate and/or unsafe and can make the decision that it is not the indicated route for nutrition.

Jejunostomy

Surgical jejunostomy tubes are the preferred approach for sustaining nutritional rescue and can be placed laparoscopically using a needle-catheter technique or by laparotomy using a Witzel tunnel. Fontana and Barnett describe improved nutrition in 57% and decreased hospitalizations in 52% of GP patients treated with feeding jejunostomy . Jejunal tube feeding does not halt disease progression but provides stability by providing non IV access for medications, fluids, and calories as well as “buys time” for treatment to work. Surgical jejunostomy or feeding endoscopic jejunal extension serve as a bridge establishing nutritional rescue and preparing for further surgical therapy .

Commentary: The surgically placed J-tube is the preferred method for sustained nutrition. During the procedure, a biopsy of gastric smooth muscle can also be of value to study the interstitial cell of Cajal, smooth muscle for fibrosis and neurons of the enteric nervous system. The recommended size is a 14 French to accommodate introducing dissolved medications. It is also key to suture the J-tube at the site of skin entry so it does not come out accidentally. The “law of jejunal feedings” is that oral and enteral feeds cannot be given together. The hormonal regulation induced by caloric absorption inhibits gastric emptying, and if oral intake is attempted during J-tube feeding, then vomiting will result. J-tube feeding is recommended only at night from 7 to 8 p.m. to 7–8 a.m. the next day at rates up to 80–100 cc/hr as tolerated. During the day, degrees of oral intake are attempted along with medications. Total caloric intake from both sources can be calculated and J-tube calories slowly decreased as oral intake increases. When not being used during the day, the J-tube needs to be flushed every 6 hours with 10–20 cc’s of water to prevent the possibility of clogging. Medications can also be dissolved and carefully injected through the J tube with follow up flushing. In addition, free water and/or electrolytes can be added avoiding the need for IV fluids.

Surgical management: pyloroplasty

A recent study by Shada et al. demonstrates that surgical PP can serve as an effective primary therapeutic approach in GP . Endoscopic interventions to include botulinum toxin injection and stenting at the pylorus can be used selectively to help predict the efficacy of stand-alone pyloroplasty PP . Interval response to these temporary interventions does have some predictive ability of a positive response to PP . Manometry demonstrates that pyloric contractions are of higher amplitude and longer duration in some diabetics with gastroparesis suggesting the entity of “pylorus spasm.” PP functionally reduces the barrier to gastric emptying . The present focus is on the endoFLIP technique to assess the compliance of the pylorus as extensively described in Chapter 34 , (written by Clarke and McCallum) where the roles of botulinum toxin and pyloric stenting are also discussed.

The standard surgical technique is the Heineke-Mikulicz PP. It should be noted that other described techniques to include the Jaboulay and Finney evolved to treat complications of peptic ulcer disease, specifically the standard vagotomy and pyloroplasty . Techniques most ideal to treat GP create a gastro-duodenostomy (organo-axial axis) dividing the pyloric muscle and separating muscular columns. Transverse closure (mesentero-axial) of this incision renders the valve incompetent and increases the outlet diameter which functionally increases gastric emptying. This technique is commonly reported by laparoscopic and robot-assisted techniques that allow either single layer full-thickness closure or double layer closure. Known complications in the peptic ulcer surgery era included dumping syndrome, but in the gastroparesis setting with often accompanying slow small bowel and colon transit, then the accelerated gastric emptying actually helps constipation .

Routine operative techniques include suspension of the cephalic and caudal ends of the pyloric ring followed by entry into the stomach using a harmonic scalpel. The incision is carried across the muscular pyloric band and extended into the duodenum . Special care is taken to ensure that the incision on the stomach extends 2 centimeters or greater with matching length on the anterior duodenal wall. Special care is taken to close the gastro-duodenostomy in a transverse fashion. Shada et al. describes running sutures starting from the center of the wound followed by a full-thickness closure with absorbable sutures. Others such as Davis et al. describe and inner running absorbable suture layer running from each end and meeting in the center followed by a second layer of permanent suture placed in a Lembert fashion to dunk the mucosal surface . ( Fig. 31.1 ) Precise surgical suturing is required to prevent subsequent leak from the surface of the repair which can lead to complications of fistula formation and delayed pocket site infections. Routine intra-operative endoscopy is utilized to test for leaks and assess for a patent pyloric channel. There is no evidence that the size of the PP alone determines the degree of improved gastric emptying by scintigraphy, although it was well known from the peptic ulcer surgery era that size correlates with symptoms of dumping syndrome .