Aetna considers intestinal transplantation medically necessary for persons who have failed total parenteral nutrition (TPN) when the selection criteria below are met.

Parenteral nutrition (see CPB 0061 - Nutritional Support) entails the administration of micronutrients and macronutrients via catheters in central or peripheral veins.  In most cases, the central venous route is used.  For long-term TPN, a central catheter (e.g., Hickman, Broviac, PIC) is placed subcutaneously in the anterior chest.  Indicators of failed TPN are liver failure, thrombosis, frequency of infection, and dehydration as demonstrated in the following clinical situations:

• Frequent episodes of severe dehydration despite intravenous fluid supplement in addition to TPN.  Under certain medical conditions such as secretory diarrhea and non-constructible gastro-intestinal (GI) tract, the loss of the GI and pancreatobiliary secretions exceeds the maximum intravenous infusion rates that can be tolerated by the cardiopulmonary system.  Frequent episodes of dehydration are detrimental to all body organs, especially the kidney and the central nervous system with the development of multiple kidney stones, renal failure, and permanent brain damage.
• Frequent line infection and sepsis.  The development of 2 or more episodes of systemic sepsis due to line infection per year that requires hospitalization indicates failure of TPN therapy.  A single episode of line-related fungemia, septic shock and/or acute respiratory distress syndrome are considered indicators of TPN failure.
• Impending or overt liver failure due to TPN-induced liver injury.  The clinical signs include elevated serum bilirubin and/or liver enzymes, splenomegaly, thrombocytopenia, gastro-esophageal varices, coagulopathy, stomal bleeding or hepatic fibrosis/cirrhosis.
• Other complications leading to loss of vascular access.  TPN failure may due to inadequate TPN access, which is an indication for intestinal transplantation.
• Thrombosis of the major central venous channels, jugular, subclavian, and femoral veins.  Thrombosis of 2 or more of these vessels is considered a life-threatening complication and failure of TPN therapy.  The consequence of central venous thrombosis is a lack of access for TPN infusion, fatal sepsis as a result of infected thrombi, pulmonary embolism, superior vena cava syndrome, or chronic venous insufficiency.
  

Selection Criteria: Aetna considers intestinal transplant medically necessary for the indications listed above for persons who meet the transplanting institution's protocol eligibility criteria.  In the absence of a protocol, Aetna considers intestinal transplant medically necessary for the indications listed above when all of the following selection criteria are met:

1. Absence of acute or chronic active infections that are not effectively treated; and
2. Adequate cardiovascular function (ejection fraction greater than or equal to 40 %); and
3. Adequate liver and kidney function, defined as a bilirubin of less than 2.5 mg/dL and a creatinine clearance of greater than 50 ml/min/kg; and
4. No active alcohol or chemical dependency that interferes with compliance to a strict treatment regimen.  Persons with a history of drug or alcohol abuse must be abstinent for at least 3 months before being considered a transplant candidate eligible for coverage; and
5. No uncontrolled and/or untreated psychiatric disorders that interfere with compliance to a strict treatment regimen; and
6. Absence of inadequately controlled HIV/AIDS, defined as:
   

A combined intestinal and liver transplant is considered medically necessary for persons with advanced liver disease necessitating liver transplantation (see CPB 0596 - Liver Transplantation) who meet the medical necessity criteria above (other than the requirement for adequate liver function).  Note: In candidates for a combined transplant, adequacy of renal function should be assessed with a measured glomerular filtration rate (GFR), as a calculated GFR is inaccurate in advanced liver disease.

Contraindications: Intestinal transplant is considered not medically necessary for persons with the following contraindications:

• Advanced neurological disorders (e.g., neuroaxonal dystrophy, Tay-Sachs disease, Niemann-Pick disease and variants, neuronal ceroid lipofuscinosis, and Huntington disease);
• Congestive heart failure with refractory symptoms and ejection fraction less than 40 %;
• Malignancy, other than non-melanomatous skin cancer, that is not effectively treated such that there is a substantial risk of recurrence;
• Multi-organ failure;
• Presence of other GI diseases (e.g., bleeding peptic ulcer, diverticulitis, chronic hepatitis);
• Sepsis.

Aetna considers measurement of fecal calprotectin experimental and investigational as a test for intestinal allograft rejection because its clinical value has not been established.

See also CPB 0342 - Intestinal Rehabilitation Programs.

Intestinal transplantation has become the treatment of choice for patients with chronic intestinal failure whose illness can not be maintained on total parenteral nutrition (TPN).  The term "intestinal failure" refers to gastro-intestinal (GI) function insufficient to meet body fluid and nutrient requirements; it includes short bowel syndrome (SBS) and severe motility disorders (e.g., chronic intestinal pseudo-obstruction syndrome in children and congenital intractable intestinal mucosa disorders).  Short bowel (also known as short gut) syndrome is a condition in which the absorbing surface of the small intestine is inadequate as a result of extensive disease or surgical removal of a large segment of the small intestine.  Patients with SBS are unable to obtain adequate nutrition from enteral feeding.

In infants, SBS is generally due to congenital anomalies.  Common causes of a SBS in infants and children include microvillus atrophy, intestinal atresia, midgut volvulus, complicated gastroschisis, aganglion syndrome, and necrotizing enterocolitis.  In adults, severe SBS usually occurs following a massive small bowel resection, which results in rapid intestinal transit and loss of absorptive function.  Common causes of SBS in adults include Crohn's disease, desmoid tumors (familial polyposis with Gardner’s syndrome), radiation enteritis, iatrogenic jejunal-ileal bypass (for morbid obesity), mesenteric venous thrombosis, superior mesenteric artery thrombosis, and traumatic mesenteric transection (blunt abdominal trauma).

Parenteral nutrition and home parenteral nutrition are the mainstay of therapy for children with SBS and other causes of intestinal failure.  Most infants with SBS eventually wean from parenteral nutrition, and most of those who do not wean tolerate parenteral nutrition for an extended period of time.  However, a subgroup of patients with intestinal failure who remain dependent on parenteral nutrition will develop life-threatening complications as a consequence of standard therapy.  The literature indicates that intestinal transplantation is recommended for this select group.  The majority of intestinal transplantation recipients are children, especially those under the age of 5.

Indications for intestinal transplantation include parenteral nutrition-associated liver disease, recurrent sepsis, and threatened loss of central venous access.  The literature suggests children with liver dysfunction should be considered for isolated intestinal transplantation before irreversible, advanced bridging fibrosis or cirrhosis supervenes, for which a combined liver and intestinal transplant is necessary.  Irreversible liver disease is suggested by hyperbilirubinemia persisting beyond 3 to 4 months of age combined with features of portal hypertension such as splenomegaly, thrombocytopenia, or prominent superficial abdominal veins.

In children, the 1- and 3-year graft survival rates for isolated small bowel and combined small bowel and liver transplantations range from 40 to 50 %, while the 1- and 3-year patient survival rates range from 80 to 100 %, depending on the age range of the patient.  Successful transplant recipients resume unrestricted oral diets.  Despite the use of potent immunosuppressive agents, rejection rates are still 50 % or higher.  Sepsis rates are also higher for patients who have had intestinal transplantation than for those who have received other organs because of bacterial translocation from the gut secondary to preservation injury and graft rejection.  Graft and patient survival rates after intestinal transplantation are comparable to rates after lung transplantation.

In addition to rejection and infection (bacterial, fungal, and viral), other complications of intestinal transplantation are graft-versus-host disease, cytomegalovirus infection as well as post-transplant lymphoproliferative disease associated with aggressive immunosuppression and Epstein-Barr virus.

Sudan et al (2007) stated that protocol endoscopy with biopsy is currently the gold standard of small bowel transplantation (SBTx) monitoring, however it is invasive, costly, needs skilled operator, may require anesthesia and may cause complications.  These researchers investigated fecal calprotectin level (FCL) as a candidate non-invasive marker for monitoring patients after SBTx.  Ileostomy effluents were collected at various post-operative days before endoscopy and biopsy.  Fecal calprotectin levels were measured by enzyme-linked immunosorbent assay and a cut-off level of 100 ng/mg was considered positive.  Results were retrospectively evaluated in combination with clinical, endoscopic, and histopathological findings.  Fecal calprotectin levels were presented as median ng/mg.  Fecal calprotectin levels were measured in 122 samples that were obtained from 29 patients after SBTx.  Only 1 of 69 positive FCL did not accompany abnormal findings.  Retrospective evaluation showed that 11 samples from 6 patients (FCL: 217) coincided with rejection episodes, 6 samples from 3 patients (FCL: 125) coincided with viral enteritis, 51 samples from 21 patients (FCL: 207) coincided with non-specific inflammation, 11 samples from 2 patients (FCL: 998) coincided with chronic intestinal ulceration, and finally 50 samples from 19 patients (FCL: 43) coincided with normal findings.  No significant FCL difference was found between rejection, infection, and inflammation.  Evolution in FCL in transplant recipients showed that FCL can predict rejection days before histopathological diagnosis.  The authors concluded that FCL is a promising clinical screening test for intestinal allograft rejection.  The major drawback of this study was that it was a retrospective study of selected patient samples with known diagnosis.  If the clinical utility of FCL is confirmed by prospective validation studies, its use may avoid unnecessary protocol endoscopy with biopsy.