Small intestinal transplantation in humans with or without the colon

The impact of colonic allograft inclusion on intestinal transplantation outcomes: Results from UNOS/OPTN database analysis

BACKGROUND

Outcomes of intestinal transplantation with colon allograft (ICTx) remain controversial. We aimed to assess the outcomes of ICTx in comparison to intestinal transplantation without colon (ITx) using the UNOS/OPTN registry database.

METHODS

We retrospectively reviewed 2612 patients who received primary intestinal transplants from 1998 to 2020. The rates of acute rejection (AR) within 6 months after transplant were compared between ICTx and ITx. Risk factors of 6-month AR were examined using logistic regression model by era. Furthermore, conditional graft survival was analyzed to determine long-term outcomes of ICTx.

RESULTS

Of 2612 recipients, 506 (19.4%) received ICTx. Graft and patient survival in ICTx recipients were comparable to those in ITx recipients. White ICTx recipients had a higher incidence of AR within 6 months compared to ITx during the entire study period (p = .002), colonic inclusion did not increase the risk of 6-month AR in the past decade. ICTx recipients who experienced 6-month AR had worse graft and patient survival compared to those who did not (p <.001 and p = .004, respectively). Among patients who did not develop 6-month AR, Cox proportional hazard model analysis revealed that colonic inclusion was independently associated with improved conditional graft survival.

CONCLUSIONS

In the recent transplant era, colonic inclusion is no longer associated with a heightened risk of 6-month AR and may provide better long-term survival compared to ITx when AR is absent. Risk adjustment for rejection and proper immunosuppressive therapy are crucial to maximize the benefits of colonic inclusion.

25 Years of a Standardized Technique for Living Donor Intestinal Transplantation: A Systematic Review

A safe, reproducible and standardized surgical technique for intestinal procurement and transplantation from a living donor (LD) was introduced in 1997 and has been used in the majority of cases since. The key principles are: 1. procurement of 180-200 cm of distal ileum in adults (about 60-150 cm in pediatric recipients depending on age and weight) on a vascular pedicle comprising the LD ileocolic vessels or terminal branches of the superior mesenteric vessels, 2. the terminal ileum (30-40 cm of the most distal ileum), the ileocecal valve and the cecum remain with the donor to not interfere with B12-absorption and bowel transit time, 3. systemic venous drainage with anastomoses between the LD ileocolic vessels and the recipient's infrarenal aorta and vena cava, and 4. restoration of recipient bowel continuity through proximal anastomosis and distal graft ileostomy for biopsy access and graft monitoring. Recipients of a successful LD intestinal transplant become total parenteral nutrition (TPN)-independent within a few weeks posttransplant. LD vs deceased donor (DD) intestinal transplants can be performed in a more timely fashion. Hence, LD (in contrast to DD) intestinal transplants are also pre-emptive procedures in patients with advanced, but still reversible, TPN-induced liver disease and help reduce the wait-list mortality for combined DD intestinal and liver transplants. Life-saving combined LD intestinal and liver transplants, albeit rare, have also been successfully performed either simultaneously or subsequently. There have been no reported deaths or major complications of living intestinal donors. A better metabolic profile has been reported in some donors post-donation. In total, 85 documented LD intestinal transplants have been performed worldwide at over 20 different transplant centers in 12 different countries. In about 70 transplants, the standardized technique was used. There has been no difference in outcome between LD vs DD intestinal transplants. Long-term studies have shown that > 10 year of graft function is not uncommon. Since the introduction of the standardized surgical technique, LD intestinal transplantation has evolved from an experimental to an established and standardized procedure.

Pediatric Intestinal Transplantation

Pediatric intestinal transplantation has moved from the theoretic to an actual therapy for children with irreversible intestinal failure who are suffering from complications of total parenteral nutrition. Owing to significant advancement in the management of intestinal failure and prevention of parenteral nutrition-related complications that have led to reduction in incidence of parenteral nutrition-associated liver disease and have improved intestinal adaptation, the indications for intestinal transplantation are evolving. Long-term outcomes have improved, but challenges in long-term graft function owing to chronic rejection and immunosuppressant-related complications remain the major opportunities for improvement.

Infectious Disease Transmission through Cell, Tissue, and Organ Transplantation: Reducing the Risk through Donor Selection

The incidence of cell transplant-transmitted infection is unknown and can only be inferred from prospective studies–that have not yet been performed and reported. The possibility of donor-to-recipient disease transmission through cell transplant therapy can be considered by reviewing the risk associated with other transplanted tissues and organs. Viral, bacterial, and fungal infections have been transmitted via transplantation of organs, tissue allografts such as bone, skin, cornea, and heart valves, and cells such as islets, hematopoietic stem cells, and semen. Several types of protozoan and worm parasites have been transferred via organ transplants. Bone allografts have transmitted hepatitis, tuberculosis, and human immunodeficiency virus (HIV-1). Corneas have transmitted rabies, Creutzfeldt-Jakob disease (CJD), hepatitis B (HBV), cytomegalovirus (CMV), herpes simplex virus (HSV), bacteria, and fungi. Heart valves have been implicated in transmitting tuberculosis and hepatitis B. HIV-1 and CMV seroconversion has been reported in patients receiving skin from seropositive donors. CJD has been transmitted by dura and pericardium transplants. Over the past several years, improvements in donor screening criteria, such as excluding potential donors with infection and those with behaviors risky for HIV-1 and hepatitis infection, and introduction of new donor blood tests have greatly reduced the risk of HIV-1 and hepatitis and may have nearly eliminated the risk of tuberculosis and CJD. Prior to use, many tissues are exposed to antibiotics, disinfectants, and sterilants, which further reduce or remove the risk of transmitted disease. Because organs, cells, and some tissue grafts cannot be subjected to sterilization steps, the risk of infectious disease transmission remains and thorough donor screening and testing is especially important.

Current status of intestinal and multivisceral transplantation

Clinical-nutritional autonomy is the ultimate goal of patients with intestinal failure (IF). Traditionally, patients with IF have been relegated to lifelong parenteral nutrition (PN) once surgical and medical rehabilitation attempts at intestinal adaptation have failed. Over the past two decades, however, outcome improvements in intestinal transplantation have added another dimension to the therapeutic armamentarium in the field of gut rehabilitation. This has become possible through relentless efforts in the standardization of surgical techniques, advancements in immunosuppressive therapies and induction protocols and improvement in postoperative patient care. Four types of intestinal transplants include isolated small bowel transplant, liver-small bowel transplant, multivisceral transplant and modified multivisceral transplant. Current guidelines restrict intestinal transplantation to patients who have had significant complications from PN including liver failure and repeated infections. From an experimental stage to the currently established therapeutic modality for patients with advanced IF, outcome improvements have also been possible due to the introduction of tacrolimus in the early 1990s. Studies have shown that intestinal transplant is cost-effective within 1-3 years of graft survival compared with PN. Improved survival and quality of life as well as resumption of an oral diet should enable intestinal transplantation to be an important option for patients with IF in addition to continued rehabilitation. Future research should focus on detecting biomarkers of early rejection, enhanced immunosuppression protocols, improved postoperative care and early referral to transplant centers.

Intestinal Transplantation in Pediatric Patients

Intestine transplantation has evolved into a feasible alternative for children with permanent intestinal failure and life-threatening complications related to total parenteral nutrition. Although the first transplantations were done nearly 40 years ago, long-term survival has only been achieved in the last decade. Nearly 700 intestinal transplantations have been performed internationally since 1985, with an overall patient survival of greater than 50%. Improvements in patient selection, medical management, and assessment and treatment for rejection and infection have contributed to the increased survival. This article will discuss current results and medical management strategies for this innovative type of transplantation for children with end-stage short gut syndrome.

The concept of gut rehabilitation and the future of visceral transplantation

In the 1990s, the introduction of visceral transplantation fuelled interest in other innovative therapeutic modalities for gut rehabilitation. Ethanol lock and omega-3 lipid formulations were introduced to reduce the risks associated with total parenteral nutrition (TPN). Autologous surgical reconstruction and bowel lengthening have been increasingly utilized for patients with complex abdominal pathology and short-bowel syndrome. Glucagon-like peptide 2 analogue, along with growth hormone, are available to enhance gut adaptation and achieve nutritional autonomy. Intestinal transplantation continues to be limited to a rescue therapy for patients with TPN failure. Nonetheless, survival outcomes have substantially improved with advances in surgical techniques, immunosuppressive strategies and postoperative management. Furthermore, both nutritional autonomy and quality of life can be restored for more than two decades in most survivors, with social support and inclusion of the liver being favourable predictors of long-term outcome. One of the current challenges is the discovery of biomarkers to diagnose early rejection and further improve liver-free allograft survival. Currently, chronic rejection with persistence of preformed and development of de novo donor-specific antibodies is a major barrier to long-term graft function; this issue might be overcome with innovative immunological and tolerogenic strategies. This Review discusses advances in the field of gut rehabilitation, including intestinal transplantation, and highlights future challenges. With the growing interest in individualized medicine and the value of health care, a novel management algorithm is proposed to optimize patient care through an integrated multidisciplinary team approach.

The development of a canine anorectal autotransplantation model based on blood supply: a preliminary case report

Colostomy is conventionally the only treatment for anal dysfunction. Recently, a few trials of anorectal transplantation in animals have been published; however, further development of this technique is required. Moreover, it is crucial to perform this research in dogs, which resemble humans in anorectal anatomy and biology. We designed a canine anorectal transplantation model, wherein anorectal autotransplantation was performed by anastomoses of the rectum, inferior mesenteric artery (IMA) and vein, and pudendal nerves. Resting pressure in the anal canal and anal canal pressure fluctuation were measured before and after surgery. Graft pathology was examined three days after surgery. The anal blood supply was compared with that in three beagles using indocyanine green (ICG) fluorescence angiography. The anorectal graft had sufficient arterial blood supply from the IMA; however, the graft's distal end was congested and necrotized. Functional examination demonstrated reduced resting pressure and the appearance of an irregular anal canal pressure wave after surgery. ICG angiography showed that the pudendal arteries provided more blood flow than the IMA to the anal segment. This is the first canine model of preliminary anorectal autotransplantation, and it demonstrates the possibility of establishing a transplantation model in dogs using appropriate vascular anastomoses, thus contributing to the progress of anorectal transplantation.

Inclusion of the colon in intestinal transplantation

PURPOSE OF REVIEW

Inclusion of the colon as a component of an intestinal graft has evolved over the past two decades. Initially thought to be hazardous and abandoned by many centers, colon inclusion has now proven to be an integral component of the intestinal transplant graft.The purpose of this review is to summarize the history of colon inclusion, the physiology of the colon, surgical techniques of colon inclusion, and outcome data.

RECENT FINDINGS

Recent studies at centers of excellence report the efficacy and safety of colon inclusion in intestinal transplantation. Quality-of-life indicators, stool patterns, fecal continence, and parenteral nutrition weaning were noted to be improved in recipients of colonic inclusion. Complex intestinal transplant case series were reported with no adverse effects of colon inclusion.

SUMMARY

Colon inclusion provides a necessary function in intestinal transplantation by taking advantages of its physiologic functions of water absorption, residue breakdown, and storage. Current clinical evidence supports the efficacy of selective and cautious use of the colon in intestinal transplantation.

Five hundred intestinal and multivisceral transplantations at a single center: major advances with new challenges

OBJECTIVE

To assess the evolution of visceral transplantation in the milieu of surgical technical modifications, new immunosuppressive protocols, and other management strategies.

SUMMARY BACKGROUND DATA

With the clinical feasibility of intestinal and multivisceral transplantation in 1990, multifaceted innovative tactics were required to improve outcome and increase procedural practicality.

METHODS

Divided into 3 eras, 453 patients received 500 visceral transplants. The primary used immunosuppression was tacrolimus-steroid-only during Era I (5/90–5/94), adjunct induction with multiple drug therapy during Era II (1/95–6/01), and recipient pretreatment with tacrolimus monotherapy during Era III (7/01–11/08). During Era II/III, donor bone marrow was given (n = 79), intestine was ex vivo irradiated (n = 44), and Epstein-Barr-Virus (EBV)/cytomegalovirus (CMV) loads were monitored.

RESULTS

Actuarial patient survival was 85% at 1-year, 61% at 5-years, 42% at 10-years, and 35% at 15-years with respective graft survival of 80%, 50%, 33%, and 29%. With a 10% retransplantation rate, second/third graft survival was 69% at 1-year and 47% at 5-years. The best outcome was with intestine-liver allografts. Era III rabbit antithymocyte globulin or alemtuzumab pretreatment-based strategy was associated with significant (P < 0.0001) improvement in outcome with 1- and 5-year patient survival of 92% and 70%.

CONCLUSION

Survival has greatly improved over time as management strategies evolved. The current results clearly justify elevating the procedure level to that of other abdominal organs with the privilege to permanently reside in a respected place in the surgical armamentarium. Meanwhile, innovative tactics are still required to conquer long-term hazards of chronic rejection of liver-free allografts and infection of multivisceral recipients.

An innovative sphincter preserving pull-through technique with en bloc colon and small bowel transplantation

This report describes a new innovative pull-through technique of hindgut reconstruction with en bloc small bowel and colon transplantation in a Crohn's disease patient with irreversible intestinal failure. The approach was intersphincteric and the anastomosis was established between the allograft colon and the recipient anal verge with achievement of full nutritional autonomy and anal continence.

Intestine transplantation in children: update 2010

This article reviews the current status of pediatric intestinal transplantation, focusing on referral and listing criteria, surgical techniques, patient management, monitoring, complications after transplant, and short- and long-term patient outcome. Intestine transplantation has become the standard of care for children who develop life-threatening complications associated with intestinal failure. The results of intestinal failure treatment have significantly improved in the last decade following the establishment of gut rehabilitation programs and advances in transplant immunosuppressive protocols, surgical techniques, and posttransplant monitoring. The 1-year patient survival is now 80% and more than 80% of the children who survive the transplant are weaned off parenteral nutrition. Early referral for pretransplant assessment and careful follow-up after transplant with prompt recognition and treatment of transplant-related complications are key factors contributing to superior patient outcomes and survival. The best results are being obtained at high-volume centers with survival rates of up to 75% at 5 years.

Small Bowel and Colon Transplantation in Rats Using Porto-Portal Cuff Anastomosis

Portal versus systemic venous drainage and colon grafting are major controversies in the techniques of intestinal transplantation. The rat is the best animal for research in this field. Nevertheless, this model requires complex microvascular anastomoses that are responsible for the high incidence of technical failures. A cuff technique is an easier anastomosis method than a hand-suture. We describe a simplified rat model of small bowel and colon transplantation using a porto-portal cuff anastomosis. DONOR: The entire small bowel, cecum, and ascending colon are harvested on a vascular pedicle, consisting of a long aortomesenteric conduit and portal vein. The right colonic vessels are preserved. The graft is flushed and a cuff device is placed on the end of the portal vein. RECIPIENT: The graft is implanted through an end-to-side aorto-aorta hand-sewn anastomosis. A segment between the first and second jejunal branch is isolated between clamps to insert into the portal cuff. After reperfusion, the recipient's mesentery is divided just below the cuff anastomosis. The recipient jejunum, ileum, and ascending colon are removed en bloc, and the graft is anastomosed in continuity with the remaining naive intestine concluding the operation. This simplified technique surmounts the technical obstacles in rats because it is easily and quickly performed, maintaining the physiological portal drainage, preserving graft ileocecal valve and ascending colon, and reaching acceptable success after a short period of training.

Anesthetic management for small bowel transplantation

Small bowel transplantation is quickly becoming the therapy of choice for short-gut syndrome. Improvements in surgical techniques, immunosuppressants, and anesthetic management of patients have allowed this procedure to become the standard of care for patients with irreversible intestinal failure who are unable to continue total parenteral nutrition therapy. This article discusses the evaluation process for candidate selection, including work-up for vascular access and hypercoagulability, intraoperative management of patients (including appropriate monitoring, hemodynamic changes, fluid management, surgical techniques, and effects of immunosuppressants), and patient survival and outcome.

Tolerogenic protocols for intestinal transplantation

The intestine has long been considered as a "forbidden" organ to transplant [Ann. Surg. 216 (1992) 223-33]. This is due to the particularly challenging nature of the immunological conflict that an intestinal graft may cause: a particularly vigorous rejection response, in addition to the capacity to mount a graft-versus-host disease (GVHD) [Transplantation 37 (1984) 429]. Currently, the short-term success of intestinal transplantation (Itx) depends upon the chronic delivery of profound immunosuppression but this causes infection, malignancies--in particular posttransplant lymphoproliferative disorder (PTLD)--and direct drug toxicity. For these reasons, the results of Itx remain inferior to those of other solid organ transplants in the middle and in the long term (Intestinal Transplant Registry: www.small-bowel-transplant.org). Improved results and wider application of Itx requires the development of protocols that would facilitate acceptance of the new intestine thereby allowing to reduce the need for immunosuppression with its attending complications. Relevant experimental data and the recent evolution in the clinical strategies used to promote acceptance of intestinal grafts are reviewed.

Surgical approaches and intestinal transplantation

The surgical treatment of short-bowel syndrome has been traditionally based on the correction of mechanical obstruction, which is responsible for bacterial overgrowth syndrome, or on intestinal expansion procedures. Since the introduction of clinical intestinal transplantation by Lillehei in 1964, there have been remarkable advances in the immunosuppressive regimens to control rejection and in preservation techniques, monitoring and critical care. Newer and more powerful immunosuppressants have helped to transform intestinal transplantation into a clinical reality-transplantation can now be a life-saving procedure for patients with intestinal failure. It is currently indicated in the event of life-threatening complications of an underlying disease or from total parenteral nutrition (TPN). Rehabilitation in successful cases is excellent.

Extrinsic denervation causes a transient proabsorptive adrenergic hypersensitivity in the canine proximal colon

Our aim was to determine if extrinsic denervation alters the absorptive response of the colon to proabsorptive and prosecretory stimuli. Ten dogs underwent enteric isolation of a 50-cm proximal colonic segment; five were also randomized to undergo extrinsic denervation (DEN). At 2 and 13 wk postoperatively, net absorptive fluxes (mean +/- SEM) of water and electrolytes were determined during basal conditions and during proabsorptive low-dose (0.3 microg/kg/min) or high-dose (3 microg/kg/min) norepinephrine or prosecretory VIP (500 pg/kg/min). The net absorptive flux of water under basal conditions was decreased in DEN versus neurally intact controls at two weeks (4.0 +/- 0.6 vs 6.6 +/- 0.7 microl/min/cm, P = 0.03) but did not differ at 13 weeks (5.0 +/- 1.0 vs 5.7 +/- 0.9, P > 0.05). Low- and high-dose norepinephrine increased water absorption in both groups at two weeks; the change in flux for high-dose norepinephrine was greater in DEN versus controls (4.1 +/- 1 vs 2.1 +/- 0.6 microl/min/cm, P = 0.04). Net absorptive fluxes of Na+ and Cl- followed these trends. VIP did not alter absorption of water or electrolytes. Extrinsic denervation of the proximal colon causes a decrease in net colonic absorption and a transient, proabsorptive adrenergic hypersensitivity in colonic absorption of water and electrolytes. VIP does not have a net secretory effect in the proximal canine colon.

Intestinal transplantation in pediatric patients

Intestine transplantation has evolved into a feasible alternative for children with permanent intestinal failure and life-threatening complications related to total parenteral nutrition. Although the first transplantations were done nearly 40 years ago, long-term survival has only been achieved in the last decade. Nearly 700 intestinal transplantations have been performed internationally since 1985, with an overall patient survival of greater than 50%. Improvements in patient selection, medical management, and assessment and treatment for rejection and infection have contributed to the increased survival. This article will discuss current results and medical management strategies for this innovative type of transplantation for children with end-stage short gut syndrome.

Serum citrulline and rejection in small bowel transplantation: a preliminary report

BACKGROUND

There is no known serum marker for intestinal rejection. Serum concentrations of the amino acid citrulline arise almost exclusively from the intestinal mucosa. We examined the impact of acute cellular rejection (ACR) of intestinal allografts on serum citrulline levels.

METHODS

Citrulline concentrations were assayed in serum samples of healthy volunteers (n=6) and seven patients who underwent small bowel transplants (SBTx). Trends in mean citrulline concentrations versus degree of ACR were assessed by matching posttransplantation citrulline concentrations with patients' grade of ACR at time of serum collection. Rejection was confirmed by biopsy and graded by following standardized criteria. An additional patient had citrulline concentrations determined for 31 sequential specimens 3-60 days posttransplant.

RESULTS

Mean citrulline concentrations in controls were significantly higher than posttransplantation samples at any rejection grade. Mean concentrations declined significantly as rejection severity increased. The overall downward trend was statistically significant (P<0.05). In sequential measurements, citrulline levels increased significantly over time with declining severity of rejection. The increase in mean citrulline concentration between posttransplant days 3-16 and 52-60 was significant (P<0.01).

CONCLUSIONS

Serum citrulline levels decline with increasing grade of ACR and may be a useful serum marker for intestinal rejection.

Clinical intestinal transplantation: a decade of experience at a single center

OBJECTIVE

To assess the long-term efficacy of intestinal transplantation under tacrolimus-based immunosuppression and the therapeutic benefit of newly developed adjunct immunosuppressants and management strategies.

SUMMARY BACKGROUND DATA

With the advent of tacrolimus in 1990, transplantation of the intestine began to emerge as therapy for intestinal failure. However, a high risk of rejection, with the consequent need for acute and chronic high-dose immunosuppression, has inhibited its widespread application.

METHODS

During an 11-year period, divided into two segments by a 1-year moratorium in 1994, 155 patients received 165 intestinal allografts under immunosuppression based on tacrolimus and prednisone: 65 intestine alone, 75 liver and intestine, and 25 multivisceral. For the transplantations since the moratorium (n = 99), an adjunct immunosuppressant (cyclophosphamide or daclizumab) was used for 74 transplantations, adjunct donor bone marrow was given in 39, and the intestine of 11 allografts was irradiated with a single dose of 750 cGy.

RESULTS

The actuarial survival rate for the total population was 75% at 1 year, 54% at 5 years, and 42% at 10 years. Recipients of liver plus intestine had the best long-term prognosis and the lowest risk of graft loss from rejection (P =.001). Since 1994, survival rates have improved. Techniques for early detection of Epstein-Barr and cytomegaloviral infections, bone marrow augmentation, the adjunct use of the interleukin-2 antagonist daclizumab, and most recently allograft irradiation may have contributed to the better results.

CONCLUSION

The survival rates after intestinal transplantation have cumulatively improved during the past decade. With the management strategies currently under evaluation, intestinal transplant procedures have the potential to become the standard of care for patients with end-stage intestinal failure.

Extrinsic neural innervation mediates absorption of water and electrolytes in canine proximal colon in vivo

INTRODUCTION

Extrinsic innervation mediates a proabsorptive effect in small intestine. Our aim was to determine whether extrinsic neural input modulates similar effects in the proximal colon in vivo.

METHODS

Ten adult dogs underwent enteric isolation of a 50-cm proximal colon loop; five each were randomized to undergo extrinsic denervation (Ext Den) of the isolated colonic segment or to serve as neurally innervated controls. After recovery, a 38 degrees C electrolyte solution (Na(+) 125 meq/L, K(+) 9 meq/L, Cl(-) 75 meq/L, HC03(-) 65 meq/L) was infused at 4 ml/min into the segment. Effluent was collected in 30-min intervals for 2 h after achieving steady state (determined by 14C nonabsorbable marker recovery); four studies were conducted at 1 and 12 weeks postoperatively. Net flux of H20, Na(+), K(+), and Cl(-) was determined. Colon morphometry was evaluated at 0 and 14 weeks. Data are presented as mean +/- SEM. Unpaired t test was applied for comparisons.

RESULTS

Net absorptive flux of H20 (microL/min/cm) was decreased in Ext Den vs controls at 1 week (4.40 +/- 0.63 vs 7.92 +/- 0.92, P = 0.03) but was not different at 12 weeks (4.70 +/- 1.20 vs 5.97 +/- 0.69; P > 0.05). Na(+) and Cl(-) followed the trends in H20 absorption (P < or = 0.05). Crypt depth (microm) decreased in controls at 14 weeks vs 0 week (915 +/- 20 vs 740 +/- 07, P = 0.01) but remained unchanged in Ext Den.

CONCLUSIONS

Loss of extrinsic neural input decreases colonic absorption. This observation suggests that extrinsic neural innervation provides net proabsorptive mechanisms for absorption of water and electrolytes in the proximal canine colon.

Intestinal transplantation for the treatment of desmoid tumors associated with familial adenomatous polyposis

BACKGROUND

Desmoid tumors associated with familial adenomatous polyposis (FAP) are locally invasive. Often occurring in the mesentery of the intestine, they sometimes recur after resection. Complications can include intestinal failure and dependence on parenteral nutrition. We describe 9 patients who underwent intestinal transplantation for the treatment of desmoid tumors associated with FAP.

METHODS

Records of patients undergoing intestinal transplantation for desmoid tumors at 2 transplant centers were reviewed for patient age, sex, type of graft, procedure date, tumor site, desmoid complications, medications, extracolonic manifestations, status at follow-up, and length of survival.

RESULTS

Nine patients with FAP and intestinal failure caused by desmoid tumors were treated with isolated intestinal (n = 6), multivisceral (n = 2), or combined liver-intestinal transplantation (n = 1). Desmoid tumors recurred in the abdominal walls of 2 patients. Two patients died: one as a result of sepsis, the other because of a rupture of a mycotic aneurysm of the aortic anastomosis. One graft lost to severe rejection was replaced with a second intestinal graft. Eleven to 53 months after transplantation, 7 patients were alive, well, independent of parenteral treatment, and leading apparently normal lifestyles.

CONCLUSIONS

Transplantation of the intestine alone or as part of a multivisceral transplantation may help rescue otherwise untreatable patients with complicated desmoid tumors.

FK506 rescues peripheral nerve allografts in acute rejection

This study investigated the ability of the immunosuppressant FK506 to reverse nerve allograft rejection in progress. Eighty-four Buffalo rats received posterior tibial nerve grafts from either Lewis or Buffalo donor animals. Allografts were left untreated for either 7, 10, or 14 days before receiving daily subcutaneous FK506 injections (2 mg/kg). Time-matched control animals received either an isograft, an allograft with continuous FK506, or an allograft with no postoperative FK506 therapy. All animals underwent weekly evaluation of nerve function by walking track analysis. Experimental group animals were sacrificed either immediately prior to initiation of FK506 therapy (days 7, 10, or 14), after 2 weeks of immunosuppressive treatment, or 8 weeks postsurgery. Histomorphometric analysis, consisting of measurements of total number of nerve fibers, neural density, and percent of neural debris, demonstrated a statistically significant increase in regeneration in the isograft group relative to the untreated allograft group within 28 days of transplantation. Grafts harvested from animals receiving 2 weeks of FK506 after 7 or 10 days of rejection were histomorphometrically similar to time-matched isografts. By contrast, grafts from animals receiving 2 weeks of FK506 following 14 days without therapy resembled untreated allografts and demonstrated significant histomorphometric differences from isografts at the corresponding time point. Analysis of walking track data confirmed that relative to untreated allografts, functional recovery was hastened in animals receiving an isograft, or allograft treated with FK506. This study demonstrated that when started within 10 days of graft placement, FK506 could reverse nerve allograft rejection in rats evaluated following 2 weeks of treatment.

Comparison of rejection rate and functional outcome of small bowel transplantation alone or in conjunction with the ileocecal valve versus combined small and large bowel transplantation

Preservation of the ileocecal valve improves absorptive function and decreases the amount of small bowel needed for survival in patients with short gut syndrome. We compared the results of small and large bowel transplant (SLBTx), small bowel transplant only (SBTx), and SBTx with the ileocecal valve (ICVTx) in a porcine model. Total enterectomy was performed on 18 Yorkshire-Landrace pigs followed by orthotopic SBLTx (n = 6), SBTx (n = 6), and ICVTx (n = 6). A jejunostomy and an ileostomy were constructed for biopsies. Overall mean survival was 17 d with no statistically significant difference between groups. Rejection was seen in 6/6 SLBTx, 4/6 SBTx, and 4/6 ICVTx recipients. Acute rejection was seen in 84.3% of SLBTx, 52.3% of SBTx, and 42.5% of the ICVTx mucosal biopsy samples. Two cases of intra-abdominal infection were in the ICVTx group only. Weight loss was 147 g/d in the SLBTx group, 643 g/d in the SBTx group, and 393 g/d in the ICVTx group. While the functional outcome after SLBTx and ICVTx was noticeably better than the SBTx group, the increased rejection and intra-abdominal infection rates make transplanting the large bowel or the ileocecal valve a less attractive clinical option.

Cold preservation of the human colon and ileum with University of Wisconsin solution

The inclusion of the colon in the intestinal graft resulted in worsening patient and graft outcome and increased the incidence of infection and rejection. In this study, we examine the role of ischemia on the barrier function of the epithelium during cold ischemia. Samples were collected from 15 harvested and transplanted human donor grafts (colon, 10; ileum, 6), which were immersed in University of Wisconsin (UW) solution. Ischemia (6, 12, 24, and 48 h) and reoxygenation were performed to evaluate the mucosal electrical status using the Ussing chamber technique. The functions of enterocytes and crypt cells were tested by glucose and theophylline challenge. Modified Park's classification was applied to evaluate the severity of mucosal damage under light microscopy. The colon had higher levels of baseline potential difference, short-circuit current, and resistance than the ileum during 6 48 h of ischemia. Colonic epithelial cells responded well to theophylline stimulation at 24 h of ischemia, while there was no ileal response. The colonic mucosa was histopathologically well preserved in UW solution for 48 h, and mucosal damage induced by reoxygenation was less than in the ileum. In conclusion, electrophysiologically and histopathologically, the colon is less susceptible to cold preservation damage than the ileum during storage with UW solution.

Total parenteral nutrition and cholestasis

Hepatobiliary dysfunction is recognized as a major adverse effect of total parenteral nutrition (TPN). It is unknown if this is caused by a deficiency or toxicity of the TPN solution or the underlying pathophysiology of disease processes that require TPN therapy. This article presents algorithms for evaluating abnormal liver tests in patients on TPN and discusses treatment options and the current status of intestinal transplantation.

Pediatric transplantation

Advances in organ preservation, surgical technique, and postoperative care have permitted the rapid development of liver transplantation in children. Consequently, the applicability of this procedure has gone beyond the treatment of life-threatening complications of chronic liver disease and now includes disabling morbidities and quality-of-life issues. The use of hepatic segments for transplantation with reduced or split cadaveric grafts and living-related donors has decreased the mortality of children awaiting liver transplantation. We are presently armed with a new potent immunosuppressive drug, tacrolimus, and an understanding that the migration and grafting of passenger leukocytes of bone marrow origin is the seminal explanation for allograft acceptance. The next forefront will involve manipulation of the process not only for the transplantation of already successful whole organs--such as the liver, kidney, pancreas, and heart--but also in the development of the intestinal transplantation program. Thus, augmentation of leukocyte traffic in unconditioned recipients of cadaver allografts with concomitant intravenous infusion of donor bone marrow cells under the same immunosuppressive management of tacrolimus-prednisone treatment will be the path into the future.

Quality of life of patients after intestinal transplantation

BACKGROUND

Quality of life is an important consideration in evaluating new medical or surgical treatments. Intestinal transplantation is now available for patients with irreversible intestinal failure. We compared quality of life among patients with intestinal failure receiving home parenteral nutrition (HPN) to that among patients who underwent intestinal transplantation (ITx) at the University of Pittsburgh Medical Center.

METHODS

The results of the Quality of Life Inventory, a self-administered questionnaire, were compared among 10 ITx recipients and 10 HPN patients. Change in quality of life was examined longitudinally over a 2-year period with repeat testing in four patients in each group.

RESULTS

ITx recipients were evaluated at mean time of 2.7 years after transplantation and after a mean period of 5.3 years of intestinal failure. HPN patients were evaluated after a mean period of 5.1 years of intestinal failure and were similar to the transplant recipients in age, gender, race, social status, education, etiology, and duration of disease. Assessed quality of life was markedly similar between HPN-dependent patients and ITx recipients, with significant differences in only 2 of 25 domains, despite the difficult early postoperative course and complex management that accompany intestinal transplantation. In longitudinal follow-up (n=4), ITx recipients reported significant improvement in anxiety (P=0.02), sleep (P=0.03), and impulsiveness/control (P<0.001), reflecting a progressive adjustment to their posttransplant status.

CONCLUSION

The quality of life in ITx recipients is similar to that in HPN-dependent patients. Quality of life among ITx recipients improves over time with decreased anxiety over physical functioning. Further research and efforts to improve quality of life in transplant recipients are needed.

Quality of life after small intestinal transplantation and among home parenteral nutrition patients

BACKGROUND

The purpose of the study was to quantify changes in the quality of life of small bowel recipients before and after transplantation and of home parenteral nutrition (HPN)-dependent patients before and after therapy. We examined quality of life across multiple areas of function including physical, social, and emotional indices.

METHODS

The Quality of Life Instrument in the form of a self-administered questionnaire was completed voluntarily by the recipients of small intestinal transplants and by a cohort of HPN-dependent patients.

RESULTS

Small intestinal transplant recipients reported significant improvement in the quality of their life and function. They also rated their quality of life and function during the pretransplant, TPN-dependent period to be worse than before the development of chronic intestinal failure. Similarly, HPN recipients reported significant worsening across most areas of quality of life when they compared their premorbid period to the HPN-dependent state.

CONCLUSIONS

TPN dependence causes significant impairment in the quality of life in most areas of functioning. In contrast, small intestinal transplantation restores the quality of life among recipients with functioning grafts.

Absorptive function following small intestinal transplantation

All studies involving small intestinal transplantation and absorptive function are reviewed. The effects ischemia-reperfusion, lymphatic disruption, denervation, rejection, immunosuppressive medication, and infection are elucidated as far as the studies allow. Species differences are discussed. Conclusions regarding the major absorptive defects are drawn.

Intensive Care of the Intra-Abdominal Organ Transplant Recipient

The postoperative care of a patient who receives an intra-abdominal organ transplant is in some ways simi lar to that of any major intra-abdominal procedure. However, certain features unique to organ transplanta tion, such as the variable functional status of the newly transplanted graft, complications that are specific to the organ transplanted, and the side effects from immuno suppressive drugs, suggest that transplantation inten sive care is a distinct subspecialty in critical care medicine. Today, the majority of patients receiving an intra-abdominal transplant will have a relatively uncom plicated postoperative course. However, preoperative disposition, intraoperative misadventure, or immediate postoperative difficulty will require the availability of an intensivist experienced in transplantation. The future of intra-abdominal transplantation will be highly depen dent on progress in immunotherapy. Newer, more spe cific immunomodulators with fewer nonimmune toxici ties should result in improved organ receptance, less graft dysfunction, and improved patient survival.

Clinical intestinal transplantation: new perspectives and immunologic considerations

BACKGROUND

Although tacrolimus-based immunosuppression has made intestinal transplantation feasible, the risk of the requisite chronic high-dose treatment has inhibited the widespread use of these procedures. We have examined our 1990-1997 experience to determine whether immunomodulatory strategies to improve outlook could be added to drug treatment.

STUDY DESIGN

Ninety-eight consecutive patients (59 children, 39 adults) with a panoply of indications received 104 allografts under tacrolimus-based immunosuppression: intestine only (n = 37); liver and intestine (n = 50); or multivisceral (n = 17). Of the last 42 patients, 20 received unmodified adjunct donor bone marrow cells; the other 22 were contemporaneous control patients.

RESULTS

With a mean followup of 32 +/- 26 months (range, 1-86 months), 12 recipients (3 intestine only, 9 composite grafts) are alive with good nutrition beyond the 5-year milestone. Forty-seven (48%) of the total group survive bearing grafts that provide full (91%) or partial (9%) nutrition. Actuarial patient survival at 1 and 5 years (72% and 48%, respectively) was similar with isolated intestinal and composite graft recipients, but the loss rate of grafts from rejection was highest with intestine alone. The best results were in patients between 2 and 18 years of age (68% at 5 years). Adjunct bone marrow did not significantly affect the incidence of graft rejection, B-cell lymphoma, or the rate or severity of graft-versus-host disease.

CONCLUSIONS

These results demonstrate that longterm rehabilitation similar to that with the other kinds of organ allografts is achievable with all three kinds of intestinal transplant procedures, that the morbidity and mortality is still too high for their widespread application, and that the liver is significantly but marginally protective of concomitantly engrafted intestine. Although none of the endpoints were markedly altered by donor leukocyte augmentation (and chimerism) with bone marrow, establishment of the safety of this adjunct procedure opens the way to further immune modulation strategies that can be added to the augmentation protocol.

The plasma FK506-binding protein 12 level is related to acute cellular rejection in small bowel transplantation

Since FK506 binding protein (FKBP12) inhibits dose-dependently the immunosuppressive activity of FK506 in vitro, plasma FKBP12 levels were measured after rat small bowel transplantation (SBTx). The mean plasma FKBP12 level in untreated recipients increased significantly at the onset of acute cellular rejection (ACR) compared to that in FK506-treated recipients without rejection at the same time after SBTx (P < 0.05). In both groups, however, the mean plasma FKBP12 level did not increase at 1 day after SBTx. These results suggest that plasma FKBP levels may be affected by ACR, but not by ischemia-reperfusion injury. Therefore, the plasma FKBP12 level should be considered as one of the parameters related to the immunosuppressive activity of FK506 in SBTx.