Managing junctional haemorrhage in the combat environment

Tactical combat casualty care and the application of extremity tourniquets have saved lives in combat. In the modern combat environment junctional injuries are common and difficult to treat. Recently, junctional tourniquets have emerged as a potential solution to this problem. Junctional tourniquets can be used as an adjunct to persistent haemorrhage despite application of conventional tourniquets or in the persistently hypotensive casualty. Surgeons must have an approach to receiving patients with junctional tourniquets in place in the operating room. The algorithms presented allow for an evidence-based and command-driven implantation of junctional tourniquets as part of tactical combat casualty care.

The future of resuscitative endovascular balloon occlusion in combat operations

Damage control resuscitation and early thoracotomy have been used to increase survival after severe injury in combat. There has been a renewed interest in resuscitative endovascular balloon occlusion of the aorta (REBOA) in both civilian and military medical practices. REBOA may result in visceral and limb ischaemia that could be harmful if use of REBOA is premature or prolonged. The purpose of this paper is to align our experience of combat injuries with the known capability of REBOA to suggest an implementation strategy for the use of REBOA in combat care. It may replace the resuscitative effect of thoracotomy; can provide haemostasis of non-compressible torso injuries such as the junctional and pelvic haemorrhage caused by improvised explosive devices. However, prehospital use of REBOA must be in the context of an overall surgical plan and should be restricted to deployment in the distal aorta. Although REBOA is technically easier than a thoracotomy, it requires operator training and skill to add to the beneficial effect of damage control resuscitation and surgery.

Scarpa's fascia and clinical signs: the role of the membranous superficial fascia in the eponymous clinical signs of retroperitoneal catastrophe

INTRODUCTION

The membranous superficial fascia (MSF) was described early in the 19th century, as was its role in the clinical sign of urethral disruption. Clinical signs of haemorrhage or leakage of pancreatic and biliary fluid into the retroperitoneum, which were described throughout the 20th century, all relied on circumscribed discolouration of the skin of the torso. The objective of this study was to relate the anatomy of the MSF to clinical signs of retroperitoneal catastrophe.

METHODS

The MSF was dissected in the torso of seven embalmed cadavers to note its extent and its attachments. The attachments of the MSF were mapped to the areas of skin discolouration that are described in the clinical signs.

RESULTS

The well known extent of the MSF in the inguinal region, its continuation into the perineum and its attachment to the fascia lata of the thigh were confirmed with our method of dissection. Dissection was continued superiorly, demonstrating continuation of the MSF over the entire torso with loose fibrous attachment of the MSF to the deep fascia. The MSF is firmly adherent to the midline of the abdomen except for the umbilicus, to a horizontal line below the clavicles and laterally in the abdomen to form pockets. The lines of firm adhesion correspond with the borders of the discoloured areas described in the clinical signs.

CONCLUSIONS

Circumscription of discolouration seen in the eponymous clinical signs of retroperitoneal catastrophe is explained by confinement of coloured retroperitoneal fluid by the MSF and its deep attachments.

Treatment of rectal war wounds

Treatment strategies for penetrating rectal injuries (PRI) in civilian settings are still not uniformly agreed, in part since high-energy transfer PRI, such as is frequently seen in military settings, are not taken into account. Here, we describe three cases of PRI, treated in a deployed combat environment, and outline the management strategies successfully employed. We also discuss the literature regarding PRI management. Where there is a major soft tissue component, repetitive debridement and vacuum therapy is useful. A loop or end colostomy should be used, depending on the degree of damage to the anal sphincter complex.

Management of devastating ocular trauma--experience of maxillofacial surgeons deployed to a forward field hospital

Combat-related eye injuries continue to increase in frequency and are generally secondary to Improvised Explosive Devices. Many ocular injuries are potentially preventable by the wearing of ballistic eye protection. The management of penetrating eye trauma is normally outside the routine practice of maxillofacial surgeons in the UK. The aim of this paper is to describe the surgical techniques used in the modern management of devastating ocular trauma including selected case examples managed by British military maxillofacial surgeons deployed to Afghanistan.

Recombinant activated factor VII in the treatment of non-haemophilia patients: physician under-reporting of thromboembolic adverse events

The objective of this study was to determine if clinically important thromboembolic adverse events (TAEs) because of recombinant activated factor VII (rFVIIa) administration are being under-reported. rFVIIa is a potent haemostatic agent with a short half-life of 2.6 h that is increasingly used in 'off-label' situations. Retrospective review of 94 patients who received rFVIIa during 1 January 2003 to 30 June 2007 was carried out at a tertiary care centre. Sixty-nine patients, 32 females and 37 males, mean age 55 years (18-84 years), satisfied study criteria of off-label usage. This was a high-risk population with 33 (48%) deaths. A mean dose of 8.2 mg (2.4-19.2 mg) was administered in two average divided doses. Thirty-six potential TAEs were identified in 29 patients, and of these, 12 patients had TAEs deemed to be rFVIIa related and were identified on average 8.8 days after exposure to rFVIIa. Forty-eight (70%) physician questionnaires were completed; however, no TAEs were reported in these questionnaires or on chart review. Potential clinically significant TAEs are being under-reported by treating physicians. Until further evidence, we suggest the urgent need to develop consensus recommendations for utilization and required follow up to monitor the safety of rFVIIa and that at a minimum, all use of rFVIIa should be regulated through a gate-keeping mechanism that ensures adherence to these policies. Furthermore, prospective registries and trials are necessary to evaluate the efficacy and safety of rFVIIa in off-label settings.

Cholecystectomy deferral in patients with endoscopic sphincterotomy

BACKGROUND

Cholecystectomy is not required in up to 64% of patients who adopt a wait-and-see policy after endoscopic clearance of common bile duct stones. Although reports of retrospective cohort series have shown a higher mortality among patients who defer cholecystectomy, it is not known if this is due to the patients' premorbid health status or due to the deferral of cholecystectomy. Randomised clinical trials of prophylactic cholecystectomy versus wait-and-see have not had sufficient power to demonstrate differences in survival.

OBJECTIVES

To evaluate the beneficial and harmful effects of cholecystectomy deferral (wait-and-see) versus elective (prophylactic) cholecystectomy in patients who have had an endoscopic biliary sphincterotomy.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Controlled Trials Register (CENTRAL) in The Cochrane Library, MEDLINE (1966 to 2007), EMBASE (1980 to 2007), and Science Citation Index Expanded without language restrictions until April 2007.

SELECTION CRITERIA

Randomised clinical trials comparing patients whose gallbladder was left in-situ after endoscopic sphincterotomy (wait-and-see group) versus patients who had cholecystectomy with either endoscopic sphincterotomy or common bile duct exploration (prophylactic cholecystectomy group), irrespective of blinding, language, or publication status.

DATA COLLECTION AND ANALYSIS

We assessed the impact of a wait-and-see policy on mortality. Secondary outcomes assessed were the incidence of biliary pain, cholangitis, pancreatitis, need for cholangiography, need for cholecystectomy, and the rate of difficult cholecystectomy. We pooled data using relative risk with fixed-effect and random-effects models.

MAIN RESULTS

We included 5 randomised trials with 662 participants out of 93 publications identified through the literature searches. The number of deaths was 47 in the wait-and-see group (334 patients) compared to 26 in the prophylactic cholecystectomy group (328 patients) for a 78% increased risk of mortality (RR 1.78, 95% CI 1.15 to 2.75, P = 0.010). The survival benefit of prophylactic cholecystectomy was independent of trial design, inclusion of high risk patients or inclusion of any one of the five trials. Patients in the wait-and-see group had higher rates of recurrent biliary pain (RR 14.56, 95% CI 4.95 to 42.78, P < 00001), jaundice or cholangitis (RR 2.53, 95% CI 1.09 to 5.87, P = 0.03), and of repeat ERCP or other forms of cholangiography (RR 2.36, 95% CI 1.29 to 4.32, P = 0.005). Cholecystectomy was eventually performed in 35% (115 patients) of the wait-and-see group.

AUTHORS' CONCLUSIONS

Prophylactic cholecystectomy should be offered to patients whose gallbladders remain in-situ after endoscopic sphincterotomy and common bile duct clearance.

Cyclosporin versus tacrolimus as primary immunosuppressant after liver transplantation: a meta-analysis

A systematic review of randomized clinical trials (RCT) was undertaken to evaluate the beneficial and harmful effects of immunosuppression with cyclosporin versus tacrolimus for liver transplanted patients. MEDLINE, EMBASE, Cochrane Central and Hepato-Biliary Group Controlled Trials Registers were searched. Using fixed and random effects model, relative risk (RR), values <1 favoring tacrolimus, with 95% confidence intervals (CI) were calculated. Of 717 potentially relevant references, 16 RCTs were eligible for inclusion. Mortality and graft loss at 1 year were significantly reduced in tacrolimus-treated recipients (Death: RR 0.85, 95% CI 0.73-0.99; graft loss: RR 0.73, 95% CI 0.61-0.86). Tacrolimus reduced the number of recipients with acute rejection (RR 0.81, 95% CI 0.75-0.88) and steroid-resistant rejection (RR 0.54, 95% CI 0.47-0.74) in the first year. Lymphoproliferative disorder or dialysis rates were not different but more de novo diabetes (RR 1.38, 95% CI 1.01-1.86) occurred with tacrolimus. More patients stopped cyclosporin than tacrolimus (RR 0.57, 95% CI 0.49-0.66). Treating 100 recipients with tacrolimus instead of cyclosporin would avoid rejection and steroid-resistant rejection in nine and seven patients respectively, graft loss and death in five and two patients respectively, but four additional patients would develop diabetes after liver transplantation.

Cyclosporin versus tacrolimus for liver transplanted patients

BACKGROUND

Most liver transplant recipients receive either cyclosporin or tacrolimus to prevent rejection. Both drugs inhibit calcineurin phosphatase which is thought to be the mechanism of their anti-rejection effect and principle toxicities. The drugs have different pharmacokinetic profiles and potencies. Several randomised clinical trials have compared cyclosporin and tacrolimus in liver transplant recipients, but it remains unclear which is superior.

OBJECTIVES

To evaluate the beneficial and harmful effects of immunosuppression with cyclosporin versus tacrolimus for liver transplanted patients.

SEARCH STRATEGY

The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded, and conference proceedings were searched (August 2005) to identify relevant randomised clinical trials. Our search included scanning of reference lists in relevant articles and correspondence with investigators and pharmaceutical companies.

SELECTION CRITERIA

All randomised clinical trials where tacrolimus was compared with cyclosporin for the initial treatment of first-time liver transplant recipients. We included randomised trials irrespective of blinding, language, and publication status.

DATA COLLECTION AND ANALYSIS

The primary outcome measure was all-cause mortality. Data were synthesised (fixed-effect model) and results expressed as relative risk (RR), values less than 1.0 favouring tacrolimus, with 95% confidence intervals (CI). Two authors assessed trials for eligibility, quality, and extracted data independently.

MAIN RESULTS

We included 16 randomised trials. The number of deaths was 254 in the tacrolimus group (1899 patients) and 302 in the cyclosporin group (1914 patients). At one year, mortality (RR 0.85, 95% CI 0.73 to 0.99) and graft loss (RR 0.73, 95% CI 0.61 to 0.86) were significantly reduced in tacrolimus-treated recipients. Tacrolimus reduced the number of recipients with acute rejection (RR 0.81, 95% CI 0.75 to 0.88), and steroid-resistant rejection (RR 0.54, 95% CI 0.47 to 0.74) in the first year. Differences were not seen with respect to lymphoproliferative disorder or de-novo dialysis rates, but more de-novo insulin-requiring diabetes mellitus (RR 1.38, 95% CI 1.01 to 1.86) occurred in the tacrolimus group. More patients were withdrawn from cyclosporin therapy than from tacrolimus (RR 0.57, 95% CI 0.49 to 0.66).

AUTHORS' CONCLUSIONS

Tacrolimus is superior to cyclosporin in improving survival (patient and graft) and preventing acute rejection after liver transplantation, but it increases the risk of post-transplant diabetes. Treating 100 recipients with tacrolimus instead of cyclosporin would avoid acute rejection and steroid-resistant rejection in nine and seven patients, respectively, and graft loss and death in five and two patients, respectively, but four additional patients would develop diabetes after liver transplantation.

Cyclosporin versus tacrolimus as primary immunosuppressant after liver transplantation: a meta-analysis

A systematic review of randomized clinical trials (RCT) was undertaken to evaluate the beneficial and harmful effects of immunosuppression with cyclosporin versus tacrolimus for liver transplanted patients. MEDLINE, EMBASE, Cochrane Central and Hepato-Biliary Group Controlled Trials Registers were searched. Using fixed and random effects model, relative risk (RR), values <1 favoring tacrolimus, with 95% confidence intervals (CI) were calculated. Of 717 potentially relevant references, 16 RCTs were eligible for inclusion. Mortality and graft loss at 1 year were significantly reduced in tacrolimus-treated recipients (Death: RR 0.85, 95% CI 0.73-0.99; graft loss: RR 0.73, 95% CI 0.61-0.86). Tacrolimus reduced the number of recipients with acute rejection (RR 0.81, 95% CI 0.75-0.88) and steroid-resistant rejection (RR 0.54, 95% CI 0.47-0.74) in the first year. Lymphoproliferative disorder or dialysis rates were not different but more de novo diabetes (RR 1.38, 95% CI 1.01-1.86) occurred with tacrolimus. More patients stopped cyclosporin than tacrolimus (RR 0.57, 95% CI 0.49-0.66). Treating 100 recipients with tacrolimus instead of cyclosporin would avoid rejection and steroid-resistant rejection in nine and seven patients respectively, graft loss and death in five and two patients respectively, but four additional patients would develop diabetes after liver transplantation.

Catastrophic microangiopathy induced by high-titre factor VIII inhibitors after liver transplantation for haemophilia A with cirrhosis

Liver transplantation may induce immune tolerance to factor VIII inhibitors but de novo development of inhibitors after transplantation may cause intractable haemorrhage. We report a patient with mild haemophilia A and high-titre FVIII inhibitors who received an orthotopic liver transplantation for complications of hepatitis C virus cirrhosis. Recombinant activated FVII was used in addition to routine haemostatic agents. Conventional immunosuppression was supplemented with antithymocyte globulin and cyclophosphamide. FVIII inhibitors disappeared from the circulation with liver transplantation but they were found to have bound to the graft endothelium, which became activated and induced catastrophic microangiopathy. A subsequent anamnestic response resulted in FVIII inhibitor titres of 1000 Bethesda Units. Uncontrollable haemorrhage persisted until the recipient's death. In patients with high-titre FVIII inhibitors resilient desensitization is required before liver transplantation.

Transplantation in Canada: report of the Canadian Organ Replacement Register

The solid organ transplant rate in Canada grew from 49.5 per million population (PMP) in 1993 to 56.8 PMP in 2002, with a peak rate of 61.0 in 2000. Most of this increase was seen in living donor kidney, liver, and lung transplants where combined rates rose twofold, from 124.9 per 1000 transplants to 243.5. Despite this, the rate of organ transplantation in the United States was 150% that of Canada in 2002. As of December 31, 2002, there were 3,956 patients waiting for an organ transplant in Canada, an 84% increase in the total number of patients on the waiting list as of December 31, 1993, 10 years ago. Cadaveric organ donation did not change over this period. An international comparison of cadaveric organ donation rates for 2001 place Canada (13.5 PMP) well below Spain (32.5 PMP) and the United States (22.6 PMP) but above Australia (9.3 PMP). As a result the annual gap between transplants performed and the waiting list has grown from 927 in 1992 to 2230 in 2001, representing an annual increase of 8.3%.

Mesh hood fascial closure in renal allograft compartment syndrome

Renal allograft compartment syndrome (RACS) is an underreported and poorly described surgical complication of renal transplantation. It occurs when a tight fascial closure compresses the graft in its limited retroperitoneal space. Without early recognition and reexploration, graft loss is inevitable. We describe a technique using a polypropylene mesh fascial closure (MHFC) to prevent and treat RACS. MHFC was performed primarily to prevent RACS and secondarily to treat this complication. Between April 2001 and October 2002, 16 patients undergoing 17 renal transplants underwent MHFC. Mean recipient body weight was 17% less than the mean donor weight. Mean follow-up was 9 months. Mean serum creatinine after primary MHFC was 148.4 micromol/L. Three of four patients with RACS regained function following secondary MHFC and had a mean serum creatinine of 155.3 micromol/L. Wound complications were seen in 5 (31%) with no wound or mesh infections and one patient was diagnosed with a lymphocele. We conclude that MHFC can be safely performed after kidney transplantation to prevent or treat RACS.

Long-term follow-up of pediatric en bloc renal transplantation

We reviewed the outcomes of pediatric en bloc renal transplantation at two Canadian centers in the cyclosporine era. Between 1984 and 2002, 16 patients received pediatric en bloc renal transplants. Mean recipient age and weight were 45 +/- 17 years and 72.2 +/- 14.4 kg, respectively. En bloc kidneys were procured from donors aged 2.1 +/- 0.8 years (range, 0.7 to 4.0), weighing an average of 14.3 +/- 2.0 kg (range, 12 to 17). All en bloc kidneys were successfully transplanted without thrombosis. All patients received calcineurin inhibitors and corticosteroids. Only three patients received antibody-based induction therapy. Rejection episodes occurring in seven grafts were all successfully treated. Mean follow-up was 3.7 years (range 0.4 to 15.0). Mean serum creatinine values at 3 months and 1 and 3 years were 138.8 +/- 54.5 micromol/L, 118.6 +/- 38.1 micromol/L, and 95.1 +/- 24.4 micromol/L, respectively. The mean creatinine value of five patients with at least 5 years follow-up was 96.8 +/- 12.3 micromol/L. Three-year graft and patient survival rates were 94%. Two deaths with functioning grafts occurred secondary to cardiac and infectious etiologies. None of the grafts were lost independent of death. We conclude that en bloc transplantation has excellent short- and long-term results. Improving graft function after 3 years represented by reduced serum creatinine suggests that these kidneys have excellent renal reserve and growth potential.

Liposomal tacrolimus lotion as a novel topical agent for treatment of immune-mediated skin disorders: experimental studies in a murine model

BACKGROUND

Systemic but not topical tacrolimus (TAC) is effective against psoriasis. Mechanical methods that enhance skin penetration by TAC increase its topical antipsoriatic effect. Liposomal delivery of TAC would increase its penetration of skin, allow for slow release and diminish its toxicity.

OBJECTIVES

To test a liposomal TAC (LTAC) formulation in a murine model.

METHODS

Drug penetration was assessed using radiolabelled LTAC, and the effect of TAC and LTAC on Balb/c skin graft survival and on ovalbumin-induced delayed-type hypersensitivity reactions was tested in C57BL/6 mice.

RESULTS

Radiotracer studies showed that topical application of LTAC achieved nine times the concentration of TAC at a target site than did systemic administration of TAC. Combination of systemic and topical LTAC significantly increased mean +/- SD skin graft survival (14.8 +/- 1.5 days) compared with systemic TAC (8.0 +/- 0.7 days) and control mice (8.4 +/- 1.2 days). LTAC was more effective systemically than TAC in the prevention of delayed-type hypersensitivity reactions. Topical LTAC also prevented this response.

CONCLUSIONS

Topical LTAC was effective in this model of immune-mediated skin disease. Because LTAC achieves higher skin concentrations than systemic TAC it may be an effective delivery system for TAC in the treatment of psoriasis.

Liposomal tacrolimus lotion as a novel topical agent for treatment of immune-mediated skin disorders: experimental studies in a murine model

BACKGROUND

Systemic but not topical tacrolimus (TAC) is effective against psoriasis. Mechanical methods that enhance skin penetration by TAC increase its topical antipsoriatic effect. Liposomal delivery of TAC would increase its penetration of skin, allow for slow release and diminish its toxicity.

OBJECTIVES

To test a liposomal TAC (LTAC) formulation in a murine model.

METHODS

Drug penetration was assessed using radiolabelled LTAC, and the effect of TAC and LTAC on Balb/c skin graft survival and on ovalbumin-induced delayed-type hypersensitivity reactions was tested in C57BL/6 mice.

RESULTS

Radiotracer studies showed that topical application of LTAC achieved nine times the concentration of TAC at a target site than did systemic administration of TAC. Combination of systemic and topical LTAC significantly increased mean +/- SD skin graft survival (14.8 +/- 1.5 days) compared with systemic TAC (8.0 +/- 0.7 days) and control mice (8.4 +/- 1.2 days). LTAC was more effective systemically than TAC in the prevention of delayed-type hypersensitivity reactions. Topical LTAC also prevented this response.

CONCLUSIONS

Topical LTAC was effective in this model of immune-mediated skin disease. Because LTAC achieves higher skin concentrations than systemic TAC it may be an effective delivery system for TAC in the treatment of psoriasis.

Liposomal tacrolimus administered systemically and within the donor cell suspension improves xenograft survival in hemiparkinsonian rats

The most widely used immunosuppressant in neural transplantation is cyclosporine- A (CsA). However, CsA has significant toxic effects when administered systemically. Tacrolimus (FK506), is a more potent immunosuppressant than CsA and can be prepared in lipid micelles (LTAC). This liposomal preparation allows for the administration of tacrolimus to the site of transplantation, possibly reducing the systemic side effects of immunosuppression. In this study we investigated the ability of LTAC to promote graft survival in hemiparkinsonian rats implanted with fetal mouse xenografts when LTAC is administered systemically to the host, when added to the donor cell suspension, or in combination. Rats with unilateral 6-hydroxydopamine lesions were transplanted with 800,000 fetal mouse ventral mesencephalic (VM) cells and were randomly divided into four groups. Group 1 was not immunosuppressed; Group 2 received daily systemic injections of LTAC; Group 3 received LTAC within the cell suspensions of mouse VM cells; and Group 4 received LTAC in the cell suspensions along with daily systemic administration of LTAC. Transplanted rats were assessed for rotational behavior 3 and 6 weeks posttransplantation. Cell survival was assessed using tyrosine hydroxylase (TH) immunohistochemistry. A significant reduction in rotational scores was observed only in the group of animals receiving the combination of LTAC-treated donor cells and systemic LTAC administration. This functional improvement correlated with a significantly greater survival of TH-immunoreactive cells in this group of animals. The other groups had poor cell survival and no significant functional improvement. We conclude that a combination of systemic immunosuppression and treatment of the cell suspension with LTAC may be a superior strategy to optimize xenograft survival. This strategy may have important implications for clinical neural transplantation.

Orthotopic liver transplantation using low-dose tacrolimus and sirolimus

Although sirolimus (SRL) binds the immunophilin FK506-binding protein-12 (FKBP-12) with greater avidity than tacrolimus (TAC), animal studies have shown that SRL and TAC act synergistically to prevent rejection. Dose-related toxicity is more often the cause of TAC discontinuation than rejection. We hypothesized that SRL would allow for a substantial reduction in the concomitant dose of TAC after liver transplantation to levels less than the threshold for toxicity. A series of 56 liver transplant recipients were administered a combination of SRL and TAC (target trough levels, 7 and 5 ng/mL, respectively). Planned weaning of steroids commenced after 3 months. Pharmacokinetic (PK) studies were undertaken. Patient and graft survival were 52 patients (93%) and 51 grafts (91%), with a follow-up of 23 months (range, 6 to 35 months). One episode (1.8%) of hepatic artery thrombosis was seen. The rate of acute cellular rejection was 14%. No extra treatment was administered in 3 of 8 patients, and the other 5 episodes responded to a single course of steroids. Cytomegalovirus infection occurred in 4 patients (7%). Renal function, glucose control, and lipid metabolism are near normal in 47 patients (84%) without additional medication. Steroid elimination is completed in 51 patients (91%). Bioavailability of SRL and TAC varied between transplant recipients, but trough levels strongly correlated with the area under the curve (r(2) = 0.82 and r(2) = 0.84, respectively). Simultaneous administration did not affect the PK profile of the drugs at this dose. The ratio of trough level to daily dose correlated between SRL and TAC. The synergistic effect seen in animal models also occurs in clinical liver transplant recipients on SRL-TAC combination immunosuppression. A low-dose combination of SRL and TAC should be compared with conventional immunosuppression in a multicenter, randomized, controlled trial.

Repopulation of liver endothelium by bone-marrow-derived cells

The mechanism underlying the immunological advantage of hepatic allografts relative to other organs is incompletely understood. We used molecular probes for the repetitive units on the Y chromosome, to identify an increasing number of male liver venous endothelial cells in needle biopsy samples of men who received female donor liver grafts. We have also shown repopulation of liver endothelium by bone marrow derived cells in a male to female mouse bone marrow transplant model. We conclude that the liver has unique venous endothelium characterised by turnover and replacement by bone marrow derived cells.

Conversion to rapamycin immunosuppression in renal transplant recipients: report of an initial experience

BACKGROUND

The aim of this study is to evaluate the effects of RAPA conversion in patients undergoing cyclosporine (CsA) or tacrolimus (Tac) toxicity.

METHODS

Twenty renal transplant recipients were switched to fixed dose rapamycin (RAPA) (5 mg/day) 0 to 204 months posttransplant. Drug monitoring was not initially used to adjust doses. The indications for switch were chronic CsA or Tac nephrotoxicity (12), acute CsA or Tac toxicity (3), severe facial dysmorphism (2), posttransplant lymphoproliferative disorder (PTLD) in remission (2), and hepatotoxicity in 1. Follow-up is 7 to 24 months.

RESULTS

In the 12 patients switched because of chronic nephrotoxicity there was a significant decrease in serum creatinine [233+/-34 to 210+/-56 micromol/liter (P<0.05) at 6 months]. Facial dysmorphism improved in two patients. No relapse of PTLD was observed. Five patients developed pneumonia (two Pneumocystis carinii pneumonia, one infectious mononucleosis with polyclonal PTLD lung infiltrate) and two had bronchiolitis obliterans. There were no deaths. RAPA was discontinued in four patients, because of pneumonia in two, PTLD in one, and oral aphtous ulcers in one. RAPA levels were high (>15 ng/ml) in 7 of 13 (54%) patients.

CONCLUSIONS

RAPA conversion provides adequate immunosuppression to enable CsA withdrawal. However, when converting patients to RAPA drug levels should be monitored to avoid over-immunosuppression and adequate antiviral and Pneumocystis carinii pneumonia prophylaxis should be given.

Is routine ureteric stenting needed in kidney transplantation? A randomized trial

BACKGROUND

Whether routine ureteric stenting in low-urological-risk patients reduces the risk of urological complications in kidney transplantation is not established.

METHODS

Eligible patients were recipients of single-organ renal transplants with normal lower urinary tracts. Patients were randomized intraoperatively to receive either routine stenting or stenting only in the event of technical difficulties with the anastomosis. All patients underwent Lich-Gregoire ureteroneocystostomy.

RESULTS

Between June 1994 and December 1997, 331 kidney transplants were performed at a single center, 305 patients were eligible, and 280 patients were enrolled and randomized. Donor and recipient age, sex, donor source, whether first or subsequent grafts, ureteric length, native renal disease, and immunosuppression were similar in each group. In the no-routine-stenting group 6 of 137 patients (4.4%) received stents after randomization for intraoperative events that in the surgeon's opinion required use of a stent. In an intention-to-treat analysis there was no difference between groups in the primary outcome cluster of obstruction or leak [routine stenting 5 of 143 (3.5%) vs. no routine stenting 9 of 137 (6.6%); P=0.23], or in either of these complications analyzed separately. All urological complications were successfully managed without major morbidity. Living donor organs and shorter ureteric length (after trimming) were univariate risk factors for leaks, although increasing donor age was associated with obstruction.

CONCLUSIONS

Routine ureteric stenting is unnecessary in kidney transplantation in patients at low risk for urological complications. Careful surgical technique with selective stenting of problematic anastomoses yields similar results.

Sirolimus-tacrolimus combination immunosuppression

A series of 32 recipients of liver, kidney, or pancreas transplants who were treated with sirolimus and low-dose tacrolimus experienced a low rate of rejection and excellent graft function without drug-related toxic effects.

Aortic valve grafts in the rat: evidence for rejection

OBJECTIVE

The histopathologic changes of fresh rat aortic valve allografts over time and the effect of cryopreservation were examined.

METHODS

Fifty-six syngeneic and allogeneic rat aortic valves were transplanted, either fresh or after cryopreservation, and then at different time points they were explanted and histologically examined in a blinded fashion.

RESULTS

Histopathologic changes in the first week are similar in syngeneic and allogeneic grafts. Fresh syngeneic grafts and leaflets retained normal structure up to 56 days. Allogeneic grafts showed retrovalvular thrombus formation with leaflet ghosts and neointimal proliferation. Cryopreservation did not alter this process.

CONCLUSIONS

Cardiac allograft valves in the rat model undergo changes that are characteristic of cell-mediated rejection and lead to valve failure.

Prevention of postsurgical adhesions with N,O-carboxymethyl chitosan: examination of the most efficacious preparation and the effect of N,O-carboxymethyl chitosan on postsurgical healing

BACKGROUND

Adhesion formation after operation can result in major complications. We have previously demonstrated that N,O-carboxymethyl chitosan (NOCC) is an effective inhibitor of postsurgical peritoneal adhesion formation. However, the optimal form of NOCC (i.e., cross-linked gel versus solution), as well as the best time of administration for optimal reduction in adhesion development, was not investigated. In addition, because adhesion formation and normal wound healing are related events and weakening of wound healing would be a serious drawback to the use of NOCC clinically, we wished to assess the effect of NOCC on the healing of surgical incisions.

METHODS

Three surgical models were used: (1) an abdominal aortic anastomosis, (2) a large bowel anastomosis, and (3) an abdominal skin incision. In the first model Sprague-Dawley rats received an abdominal aortic transection and repair. NOCC solution or gel was administered at different time points throughout the procedure. Control and NOCC-treated animals were killed 14 days after operation. The condition of the anastomosed vessel was examined, and adhesion frequency and intensity in the abdomen were scored. In the second model Sprague-Dawley rats underwent large bowel transection and repair. Control and NOCC-treated animals were killed on postoperative days 4, 7, and 14, and strength of repair was assessed by removal of the large bowel and measurement of the bursting strength of the repaired incision. In the third model rats received an abdominal incision and were immediately closed. Control and NOCC-treated animals were killed 14 days after operation, and the skin tensile strength of the wound was measured with a tensiometer.

RESULTS

In all three models studied, NOCC treatment did not adversely affect the strength of the repaired incision. NOCC solution administered before operation did not greatly reduce adhesion formation, whereas the delivery of both NOCC gel and solution after operation was most efficacious.

CONCLUSIONS

The administration of both NOCC gel and solution after operation is most efficacious, and NOCC does not compromise postsurgical healing in rats at doses that prevent peritoneal adhesion formation.

Prevention of experimental postoperative peritoneal adhesions by N,O-carboxymethyl chitosan

BACKGROUND

Postsurgical adhesion formation can result in significant morbidity and, to a lesser extent, death. The purpose of this experiment was to assess the ability of N,O-carboxymethyl chitosan (NOCC) to prevent postsurgical adhesion formation in vivo.

METHODS

Randomized groups of Sprague-Dawley rats were studied under two abdominal surgery models, the uterine horn model and the small bowel laceration model, for the ability of NOCC to reduce the incidence and severity of adhesion formation. Adhesions in animals were assessed after death by a blinded observer 10 to 14 days after surgical manipulation.

RESULTS

NOCC consistently reduced the size, strength, and number of adhesions in both rat models. NOCC was also found to be more effective than hyaluronic acid at inhibiting adhesion formation.

CONCLUSIONS

NOCC is a more effective antiadhesion agent than is the more expensive hyaluronic acid. Although the exact mechanism of NOCC's antiadhesion activity is as yet unclear, the novel chemical is of particular interest for clinical use.

Importance of minor histocompatibility antigens in the development of allograft arteriosclerosis

Although acute rejection has been mostly ameliorated with the use of powerful immunosuppressive drugs, kidney and heart transplants continue to succumb to a more chronic response characterized by intimal lesions in the graft vasculature. This late-stage response is referred to as allograft arteriosclerosis. Allorecognition is clearly involved in the initiation of this response but the relative importance of major histocompatibility (MHC) and minor histocompatibility (mH) antigens remains unclear. By taking advantage of the B10 congenic set of mice and our newly described mouse aortic interposition graft model we have been able to assess the contribution of these antigens to the development of the concentric intimal lesions characteristic of allograft arteriosclerosis. We performed transplants between syngeneic animals, animals which were disparate at both MHC and multiple mH, animals which were disparate at MHC only, and animals which were disparate at multiple mH antigens only. H-Y antigen variation was controlled for by performing all transplants between female mice. In all cases the recipients were C57BL/10 (H-2b) mice. Both cellular infiltration into the intima and resulting intimal thickness were measured at 2, 4, 8, and 13 weeks posttransplant. At all time points, the grafts from MHC disparate only donors showed less severe intimal lesions than the grafts from fully disparate or mH disparate donors. This difference reached statistical significance at 4 and 13 weeks. This suggests that mH antigens are as immunogenic as MHC antigens with respect to the generation of allograft arteriosclerosis. These findings are not unique to vascular grafts and may relate to the importance of indirect antigen presentation in the development of chronic rejection.

Prolongation of rat kidney allograft survival by nematodes

Nippostrongylus infection strongly stimulates TH2 activity in vivo. Given the evidence of cross regulation between TH2 and TH1 cells, and the link between TH1 activity and graft rejection, we examined the effects of Nippostrongylus infection on the fate of kidney allografts in rats. Both prior Nippostrongylus infection and prior treatment with a soluble worm product significantly delayed kidney allograft rejection. Control graft rejection occurred at 9.7 +/- 1.2 days whereas grafts in Nippostrongylus- or worm extract-treated recipients lasted 32.7 +/- 11.3 days and 21.5 +/- 4.6 days, respectively. At day 5 posttransplant mononuclear cell infiltration was much reduced in the Nippostrongylus-treated recipients. Flow cytometry of isolated graft-infiltrating leukocytes showed a marked decrease in infiltrating T cells (82.8% reduction) with both CD4+ cells (81.0% reduction) and CD8+ cells (84.6% reduction) being reduced. CD8+ T cells, in particular, made up a much smaller proportion of the graft-infiltrating cells (22% rather than 49%) in the Nippostrongylus-treated animals as compared with untreated controls. Immunohistochemical assay of the graft tissue confirmed the flow cytometric results. Interleukin 4 expression was clearly demonstrated by RT-PCR of the isolated graft-infiltrating leukocytes from the Nippostrongylus-treated recipients but not from the control recipients. These data are consistent with our current hypothesis that Nippostrongylus delays graft rejection by inducing a cross-regulatory suppression of TH1 activity.

Use of OKT3 monoclonal antibody as induction therapy for control of rejection in liver transplantation

This report details a single center's experience with OKT3 induction immunosuppression for liver transplantation. One hundred ninety-nine consecutive, unselected adult liver recipients received OKT3 therapy for 9-10 days combined with low-dose steroids and azathioprine. Cyclosporine was begun to overlap with the last few days of OKT3 therapy. The average dose of OKT3 was 45 mg. Fifty-two patients (26.1%) experienced 57 episodes of acute rejection. The median time of onset of rejection was 18 days after grafting. Seventy-eight percent of the rejection episodes were steroid-sensitive. Recurrent rejection was uncommon and the need for OKT3 retreatment was infrequent. One year actuarial graft and patient survival was 79.7% and 82.3% respectively. Based on this evidence, it appears that OKT3 prophylaxis provides good control of acute rejection with a very low incidence of recurrent rejection.

Development of a mouse aortic transplant model of chronic rejection

Chronic rejection is the most common cause of late graft failure after solid organ transplantation. A model of chronic rejection, the rat aortic allograft, has histologic features that parallel those in the vessels of human transplanted organs. However, the molecular tools required to dissect the immunology of chronic rejection are unavailable in the rat. We developed aortic transplantation in the mouse as a new model of chronic rejection. This will allow the use of the diversity of recombinant cytokines and monoclonal antibodies available for the mouse and its well-defined genetics to investigate chronic rejection in greater detail. We describe the perioperative care and surgical technique for the model in which a 1 cm segment of donor thoracic aorta was used to replace a section of recipient abdominal aorta below the renal arteries and above the aortic bifurcation. Mortality rates were initially high (70%) due to thrombosis and shock. Changes in technique and operator facility resulted in a high rate of success (75%). After 192 operations, the current success rate is > 80%. Mice free from complications at 12 hrs postop had indefinite survival, and after 2 months the typical vascular lesion of chronic rejection was present. This new model of chronic rejection will be a valuable tool to study the molecular immunology and genetics of chronic rejection.

Normal fasting volume and postprandial emptying of the denervated donor gallbladder in liver transplant recipients

BACKGROUND/AIMS

Truncal vagotomy causes gallbladder dilatation and possibly cholelithiasis. During liver transplantation, when the gallbladder is transplanted with the donor liver, the gallbladder and liver are extrinsically denervated. The aim of this study was to determine whether extrinsic denervation affects gallbladder volume and postprandial emptying.

METHODS

To evaluate fasting gallbladder volume, 26 transplant recipients underwent ultrasonography. Twenty-eight normal volunteers were controls. To evaluate postprandial contractility, seven transplant recipients underwent radionuclide gallbladder-emptying studies. Gastric emptying and cholecystokinin release were simultaneously determined after a fatty meal to exclude a difference in gallbladder stimulus. Sixteen normal volunteers were controls.

RESULTS

There were no differences in fasting gallbladder volume or postprandial contractility, gastric emptying, and cholecystokinin release between transplant patients and controls. Median fasting and postprandial gallbladder volumes for the transplant recipients (95% confidence) were 16 mL (12-34 mL) and 3 mL (0-8 mL), respectively, and for controls were 18 mL (13-21 mL; P = 0.73) and 3 mL (1-6 mL; P = 0.97), respectively.

CONCLUSIONS

These data do not show gallbladder dilatation or impaired postprandial gallbladder contraction in the extrinsically denervated gallbladder. This finding suggests that gallbladder dilatation may be caused by the unopposed activity of the sympathetic system after truncal vagotomy.