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S V McDiarmid

Publications and source records attributed to S V McDiarmid.

At least 19 recordsLinked to original sources
PubMed2004

P-selectin knockout mice have improved outcomes with both warm ischemia and small bowel transplantation.

AIM: To analyze the role of P-selectin in intestinal ischemia and reperfusion injury (IRI) using murine models. METHODS: A model of warm IRI wherein the SMA was occluded for 100 minutes was undertaken in the following groups (10 mice per group): Group 1 (control) wild-type (WT) C57BL6, no treatment; Group 2: 0.4 mg/kg of r-PSGL1-lg 10 minutes before and after clamping; Group 3: PSGL KO mice. Survival was assessed at 7 days; the intestine was assayed for histopathology, apoptosis, myeloperoxidase (MPO), IL1, and TNF. A second model of cold IRI followed by intestinal transplantation (IT) was undertaken in the following groups (two mice per group): Group A WT --> WT: Group B PSGL KO --> WT (1-hour ischemia); Group C: PSGL KO --> WT (2 hour ischemia). Survival only was assessed. RESULTS: Survival was 50% in group 1, 90% in group 2, and 100% in group 3. Graded histopathology and crypt apoptosis demonstrated significantly less injury in groups B and C. MPO was not different between groups. IL1 and TNF were significantly reduce in groups 2 and 3. Following IT, survival was <12 hours in group A, >7 days in group B, and <72 hours in group C. CONCLUSION: This study clearly demonstrates the importance of P-selectin in warm and cold IRI in that the blockade of P-selectin using rPSGL1-lg or the absence of P-selectin using KO mice confers a survival advantage and reduction in tissue injury. The mechanism is unclear but appears to be independent of neutrophil infiltration.

Animals↗
PubMed2004

Application of combined liver-intestinal transplantation as a staged procedure.

Liver-intestinal transplantation is a complex surgical procedure that historically has required prolonged operative periods. This report is the first series where liver-intestinal transplantation was performed as a staged procedure. Specifically, allograft reperfusion was followed by resuscitation and stabilization in an intensive care unit before completion of the transplant procedure. Triage of recipients to the intensive care unit following allograft reperfusion was determined at the time of operation and was based upon the clinical condition of the recipient including hemodynamic stability, evidence of coagulopathy, and assessment of early liver function. Medical stabilization was followed by completion of the transplant procedure and definitive abdominal closure within 72 hours. The application of combined liver-intestinal transplantation as a staged procedure demonstrated no effect upon early graft function, incidence of complications, or ability to perform a definitive abdominal closure.

Adult↗
PubMed2004

Infectious enteritis after intestinal transplantation: incidence, timing, and outcome.

AIM: To review the incidence, timing, and outcome of infectious enteritis after intestinal transplantation (IT). METHOD: A retrospective review of all patients undergoing IT at a single institution between 1991 and 2003 was analyze with standard statistical tools. RESULTS: Among 33 IT recipients, 13 (39%) developed 20 culture- or biopsy-proven episodes of infectious enteritis. The recipient demographics were 77% men and median age 2.6 years. Infections were diagnosed at a median of 76 days (32 to 1800) after IT. There were 14 viral (CMV one, rotavirus eight, adenovirus four, EBV one, three bacterial (Clostridium difficile), and three other infections (Giardia lamblia one, cryptosporidium two). Complete resolution was achieved in 17 (94%) infectious after appropriate antimicrobial or conservative therapy. Interestingly, there were six rejection episodes following infectious enteritis. Grafts were lost to rejection after rotaviral enteritis (n = 1) and adenoviral enteritis misdiagnosed as rejection (n = 1). Patient and graft survival were not adversely affected by infections. CONCLUSIONS: Infectious enteritis occurs frequently after IT. Viral agents are the cause in two-thirds of cases. With supportive care and appropriate treatment, resolution is possible in the majority of cases. Differentiating rejection and infection by histopathology can be difficult.

Adult↗
PubMed2004

Improved outcome after intestinal transplantation at a single institution over 12 years.

PURPOSE: To evaluate the outcomes of patients undergoing intestinal transplantation (IT). METHODS: Retrospective review was undertaken using existing medical records and database. RESULTS: Between November 1991 and May 2003, 114 patients were referred for consideration for IT, of which 33 patients received 37 intestinal allografts. All patients had intestinal failure and all patients had significant complications from total parenteral nutrition (TPN). TPN was the predominant cause of liver failure (63%). Combined liver intestinal grafts were used in the majority of patients. Overall 1- and 3-year patient survival is 77% and 52% with patients transplanted since 1999 having a 1- and 3-year survival of 94% and 73%, respectively. The most common cause of death was sepsis. No graft or patient was lost to cytomegalovirus or Epstein-Barr virus disease. Twenty-seven percent of allografts were lost to rejection. Long-term TPN independence is 82% for grafts more than 30 days after IT. Statistical analysis revealed several important factors impacting outcome. CONCLUSIONS: Successful IT defined as prolonged patient and graft survival and TPN independence can be readily achieved in select patients with IF and complications related to TPN therapy. Outcomes have improved with experience gained and control of viral infections and rejection.

Adolescent↗
PubMed2004

Induction therapy with interleukin-2 receptor antagonist after intestinal transplantation is associated with reduced acute cellular rejection and improved renal function.

PURPOSE: To determine the effectiveness of induction immunotherapy with interleukin-2 receptor antagonists (IL2RA) after intestinal transplantation (IT). METHODS: A single-center, retrospective study was undertaken of all patients undergoing IT using existing medical records and database. Immunotherapy was either triple (standard maintenance triple therapy [SMTT]) or IL2RA [induction IL2RA plus SMTTx] or OKT3 [induction antilymphocyte preparations plus SMTTx]). Data was collected for the first 175 postoperative days. Outcomes included pretransplant renal function, posttransplant serum creatinine normalized to age (nl-sCR), rejection (ACR), and survival. Standard statistical analysis was undertaken. RESULTS: There were no significant differences in the groups: triple (n = 10, median age 3.5 years, cGFR 106 +/- 44 mL/min), IL2RA (n = 13, median age 3.2 years, cGFR 101 +/- 61 mL/min), OKT3 (n = 4, median age 7.7 years, cGFR 104 +/- 27 mL/min). nl-sCR was significantly (P <.01) lower in IL2RA at most postoperative weeks. IL2RA had significantly fewer rejection and infectious episodes than the other two groups. Three-year patient survival was 92% in IL2RA versus 50% triple and OKT3. CONCLUSIONS: IL2RA immunotherapy after IT is associated with a lower incidence of renal dysfunction as compared with historical controls. Furthermore, IL2RA therapy resulted in a lower incidence of rejection and improved survival. IL2RA should be considered in select patients undergoing IT.

Child↗
PubMed2004

Studies of Pediatric Liver Transplantation: 2002 update. An overview of demographics, indications, timing, and immunosuppressive practices in pediatric liver transplantation in the United States and Canada.

Studies of Pediatric Liver Transplantation (SPLIT) was initiated in 1995 for the purpose of collecting comprehensive data from children undergoing liver transplantation. As of May 31, 2002, 1761 children were registered in SPLIT from 38 participating centers in the United States and Canada. This report focuses on the demographics, primary diagnoses, clinical indications for transplant, and probability of obtaining liver transplantation for the 1187 children receiving a liver transplant after registration in SPLIT. Demographic information is also provided for the 1092 children who received their first ever liver transplantation. For this cohort, we also describe immunosuppressive practices at the time of transplant, and how the use of different medications changes with time.

ABO Blood-Group System↗
PubMed2003

Current status of liver transplantation in children.

There are two critical issues on opposite ends of the timeline for patients who are eligible for liver transplantation. On the one hand, the crisis in the cadaveric organ supply makes surviving to transplant ever more risky. On the other hand, patients who receive successful transplants face the consequences of long-term immunosuppression and its potentially life-threatening complications. The donor shortage is forcing difficult decisions that affect all patients who await liver transplantation. It is important to scrutinize carefully the results of all policies that govern allocation and the ethics of the solutions we advocate to ensure that no patient subgroup is being at a disadvantage. Current immunosuppression practices are being challenged by an increasing understanding of the immunologic events triggered by the allograft and the goal to free patients from consequences of a lifetime of immunosuppression. Clinicians can expect, and perhaps require, that new immunosuppressive protocols will address how the planned intervention might be expected to advance the understanding of tolerance mechanisms. As knowledge increases, clinicians can anticipate innovative new immunosuppressive proposals. Calcineurin and steroid-free induction, the use of donor-derived bone marrow infusion, recipient pretreatment, costimulatory blockade, and new antibody induction approaches are all being proposed--often in combination--for clinical trials. Researchers face additional challenges in defining endpoints if the goal is not just the short-term reduction in rejection but the minimization, and eventual discontinuation, of immunosuppressive drugs while maintaining excellent long-term graft function. How much "failure" will be accepted and how will it be defined? How will clinicians interpret liver biopsies if they begin to accept that some lymphocytic infiltrates may be beneficial mediators of the ongoing immune activation necessary for the maintenance of tolerance? How will they adjust immunosuppression practices to the dynamic processes in the immune response that maintain tolerance? Remarkable short-term successes in providing transplants for thousands of children with liver failure have brought these challenges into sharp focus. Clinicians must seek to move the life-giving science of transplantation toward a new goal: providing long lifetimes of excellent graft function with minimal toxicity from immunosuppressive drugs and the hope of freedom from immunosuppression altogether. Pediatric liver recipients, whose grafts have inherent tolerogenic potential and for whom we can anticipate decades of life after transplant, may prove to be an ideal study population to further these goals.

Calcineurin Inhibitors↗
PubMed2003

Studies of Pediatric Liver Transplantation (SPLIT): a summary of the 2003 Annual Report.

The SPLIT database is accumulating comprehensive data on both pre- and posttransplant outcomes after pediatric liver transplantation. The relatively small numbers of children receiving any solid organ transplant, even at the largest single centers makes it difficult to study outcomes and changing trends from any single center and necessitates the formation of a large multi-center database. SPLIT has designed its data collection specifically to address outcomes relevant to children after liver transplantation such as growth and school performance and which are not collected by any other exisiting database. From the outcome data generated to date, a subset of which is presented above, hypothesis-driven studies can be designed. The first example of such a study was the development of the Pediatric Endstage Liver Disease (PELD) score. This model, which predicts death on the liver transplant waiting list for children with chronic liver disease was developed using data from SPLIT, has been adopted, and subsequently verified within the national cadaveric organ allocation system.

Adolescent↗
PubMed2001

Early graft function after pediatric liver transplantation: comparison between in situ split liver grafts and living-related liver grafts.

BACKGROUND: The systematic application of living-related and cadaveric, in situ split-liver transplantation has helped to alleviate the critical shortage of suitable-sized, pediatric donors. Undoubtedly, both techniques are beneficial and advantageous; however, the superiority of either graft source has not been demonstrated directly. Because of the potential living-donor risks, we reserve the living donor as the last graft option for pediatric recipients awaiting liver transplantation. Inasmuch as no direct comparison between these two graft types has been performed, we sought to perform a comparative analysis of the functional outcomes of left lateral segmental grafts procured from these donor sources to determine whether differences do exist. METHODS: A retrospective analysis of all liver transplants performed at a single institution between February 1984 and January 1999 was undertaken. Only pediatric (<18 years) recipients of left lateral segmental grafts procured from either living-related (LRD) or cadaveric, in situ split-liver (SLD) donors were included. A detailed analysis of preoperative, intraoperative, and postoperative variables was undertaken. Survival was estimated using the Kaplan-Meier method, and comparison of variables between groups was undertaken using the t test of Wilcoxon rank sum test. RESULTS: There were no significant differences in the preoperative variables between the 39 recipients of SLD grafts and 34 recipients of LRD grafts. The donors did differ significantly in mean age, ABO blood group matching, and preoperative liver function testing. Postoperative liver function testing revealed significant early differences in aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, prothrombin time, and alkaline phosphatase, with grafts from LRD performing better than those from SLD. SLD grafts also had significantly longer ischemia times and a higher incidence of graft loss owing to primary nonfunction and technical complications (9 vs. 2, P<0.05). However, six of these graft losses in the SLD group were because of technical or immunologic causes, which, theoretically, should not differ between the two groups. Furthermore, these graft losses did not negatively impact early patient survival as most patients were successfully rescued with retransplantation (30-day actuarial survival, 97.1% SLD vs. 94.1% LRD, P=0.745). In the surviving grafts, the early differences in liver function variables normalized. CONCLUSIONS: Inherent differences in both donor sources exist and account for differences seen in preoperative and intraoperative variables. Segmental grafts from LRD clearly performed better in the first week after transplantation as demonstrated by lower liver function variables and less graft loss to primary nonfunction. However, the intermediate function (7-30 days) of both grafts did not differ, and the early graft losses did not translate into patient death. Although minimal living-donor morbidity was seen in this series, the use of this donor type still carries a finite risk. We therefore will continue to use SLD as the primary graft source for pediatric patients awaiting liver transplantation.

Adult↗
PubMed2001

Preoperative factors associated with outcome and their impact on resource use in 1148 consecutive primary liver transplants.

BACKGROUND: Hepatic transplantation is a highly effective but costly treatment for end-stage hepatic dysfunction. One approach to improve efficiency in the use of scarce organs for transplantation is to identify preoperative factors that are associated with poor outcome posttransplantation. This may assist both in selecting patients optimal for transplantation and in identifying strategies to improve survival. METHODS: In the present work, we retrospectively reviewed consecutive liver transplants performed at the University of California at Los Angeles during a 6-year period and determined preoperative variables that were associated with outcome in primary grafts. In addition, we used the hospital's cost accounting database to determine the impact of these variables on the degree of resource use by high-risk patients. RESULTS: We found five variables to have independent prognostic value in predicting graft survival after primary liver transplantation: (1) donor age, (2) recipient age, (3) donor sodium, (4) recipient creatinine, and (5) recipient ventilator requirement pretransplant. Recipient ventilator requirement and elevated creatinine were associated with significant increases in resource use during the transplant admission. CONCLUSIONS: Patients at high risk for graft failure and costly transplants can be identified preoperatively by a set of parameters that are readily available, noninvasive, and inexpensive. Selection of recipients on the basis of these data would improve the efficiency of liver transplantation and reduce its cost.

Adult↗
PubMed2001

Orthotopic liver transplantation for autoimmune hepatitis and cryptogenic chronic hepatitis in children.

BACKGROUND: Autoimmune hepatitis (AIH) and cryptogenic chronic hepatitis (CCH) are important causes of liver failure in children, frequently necessitating orthotopic liver transplantation (OLT). The aim of this study is to review disease progression and potential differences between subgroups of children with AIH and CCH. METHODS: The medical records of 65 children diagnosed with AIH or CCH between 1980 and 1998 were evaluated. RESULTS: The median age at presentation was 9 years, 8 months (range 4 months-19 years), and the median follow-up period was 8 years (range 3 months-18 years, 10 months). Forty-one patients (63%) were female. Twenty-eight patients were Hispanic, 28 were Caucasian, 8 were African-American, and 1 was Asian. Forty-three patients (66%) were diagnosed with type 1 AIH, 8 (12%) with type 2 AIH, and 14 (22%) with CCH. Forty patients (62%) underwent OLT (51% of those with type 1 AIH, 75% of those with type 2 AIH, and 86% of those with CCH). Thirteen (33%) of the transplanted patients experienced disease recurrence. African-American patients experienced a significantly higher rate of disease recurrence post-OLT than did Hispanic patients. Seven patients (11%) died, two without OLT, and five posttransplantation. CONCLUSIONS: AIH and CCH frequently necessitate OLT in children. CCH is a more aggressive disease than Type 1 AIH among children with these disorders. Ethnicity influences the rate of disease recurrence after liver transplantation.

Adolescent↗
PubMed2001

Outcome after intestinal transplantation: results from one center's 9-year experience; discussion 1031-2.

HYPOTHESIS: Outcomes after intestinal transplantation have improved during the past decade with refinements in surgical techniques as well as advances in immunosuppression and antimicrobial therapy. DESIGN: Retrospective analysis. SETTING: Tertiary care medical center, August 1991 through December 2000. PATIENTS: Adult (5) and pediatric (12) patients with intestinal failure. All developed complications from long-term total parenteral nutrition therapy. Median age was 8.6 years and median weight was 22 kg. INTERVENTIONS: Primary intestinal transplantation with (n = 14) or without (n = 3) the liver. MAIN OUTCOME MEASURES: Patient and graft survival, viral infections, rejection, and nutritional autonomy. RESULTS: Twenty-one intestinal grafts were transplanted into the 17 recipients. All donors were cadaveric and were matched by ABO blood group and size. Patient survival at 1 and 3 years was 63% and 55%, respectively. Death-censored graft survival at 1 and 3 years was 73% and 55%, respectively. There were 1.5 acute cellular rejection episodes per graft and 3 grafts were lost to rejection. Incidences of infection with the Epstein-Barr virus and cytomegalovirus were negligible with aggressive prophylaxis and preemptive therapy. Nutritional autonomy was achieved in 69% of grafts surviving more than 30 days after intestinal transplantation. CONCLUSIONS: Intestinal transplantation is now the standard of therapy for patients with intestinal failure and complications resulting from total parenteral nutrition. Outcomes have markedly improved since initiation of the program. Aggressive immunosuppression as well as prophylaxis and preemptive antiviral therapy have led to low incidences of acute cellular rejection, Epstein-Barr virus, and cytomegalovirus. Finally, nutritional autonomy can be achieved after successful intestinal transplantation.

Adolescent↗