Allograft-related Complications Research Articles

Hepatic allograft rejection after liver transplantation: Clinicopathological debates!

Liver transplantation (LT) represents a life-saving surgical procedure and is considered the current standard of care for the majority of patients having end-stage liver disease. As known, significant progress in organ preservation techniques, perioperative care, and strict immunosuppression protocols are associated with favorable patient/graft survival post-LT. Hence, proper evaluation of liver allograft-related complications among survivors has paid great attention, particularly the rejection sequel after LT. It is a seriously underestimated cause of allograft injury, which pushes researchers for understanding the exact pathogenesis of different types and proper time diagnosis for better management of such complications. However, it still represents a challenge because of the complexities related to diagnosis and histopathology. Hence, increasing clinical awareness with earlier diagnosis of post-LT rejection is essential through stimulating further studies. Therefore, our review will focus on the clinicopathological debates regarding liver allograft loss after transplantation.

Bone allografting: an original method for biological osteosynthesis and bone reinforcement in children with osteogenesis imperfecta.

Osteogenesis imperfecta (OI) is a genetic disorder responsible for various symptoms including deformities and frequent fractures. Bone allografting is poorly documented in this condition. The objective of this study was to describe our experience and assessments in a consecutive series of OI patients. Thirty-nine lower limb allograft procedures (28 femurs, 11 tibias) were performed in 26OI patients (mean age, 12.9 years). They were classified as type III of Sillence (17), type IV (6), and 3 recessive forms. The indications for surgery were correction of deformity (19), fracture (16), and non-union (4). In all cases, bone allografting was added to reinforce areas of fragility and in 28 cases for osteosynthesis to lock the rotations at the osteotomy site and to avoid screwed metallic plate. The duration of bone consolidation and allograft fusion was assessed. Complications and Gillette functional score were reported. The mean follow-up was 6.7years (range, 2 to 10 years). On average, bone consolidation was achieved after 3.3 months and graft fusion after 7.7 months. No bone allograft-related complications were observed and there was any secondary displacement. The Gillette functional score was improved in 23 patients and stable in three cases. Complications were reported in two cases: one partial allograft resorption and one delayed consolidation of a non-union. One refracture was observed but after a significant trauma in a child who had regained significant physical activity. Bone allografting in children with OI is a reliable method of biological fixation, allowing efficient fusion and contributing to increased bone capital and functional outcome.

What's New in Musculoskeletal Tumor Surgery.

What's New in Musculoskeletal Tumor Surgery.

Cytomegalovirus-related Complications and Management in Facial Vascularized Composite Allotransplantation: An International Multicenter Retrospective Cohort Study.

There is a paucity of data on the impact of cytomegalovirus (CMV) serostatus and CMV infection on outcomes in facial vascularized composite allotransplantation. This international, multicenter, retrospective cohort study presents data on CMV and basic transplant-related demographics, including pretransplant viral D/R serostatus, and duration of antiviral prophylaxis. CMV-related complications (viremia, disease), allograft-related complications (rejection episodes, loss), and mortality were analyzed. We included 19 patients, 4 of whom received CMV high-risk transplants (D+/R-). CMV viremia was noted in 6 patients (all 4 D+/R- patients and 2 D-/R+), mostly within the first-year posttransplant, shortly after discontinuation of antiviral prophylaxis (median 2 mo). CMV disease occurred in 2 D+/R- patients. The high-risk group experienced relatively more rejection episodes per month follow-up. None of D+/R- patients suffered allograft loss due to rejection (longest follow-up: 121 mo). D+/R- patients were at increased risk of CMV-related complications. Although a higher number of rejections was noted in this group, none of the D+/R- patients lost their allograft or died because of CMV or rejection. Thus, CMV D+/R- face transplantation can likely be safely performed with prophylaxis, active surveillance, and prompt treatment.

Letter: Sacroplasty Augmentation of Instrumented Pelvic Reconstruction After High Sacrectomy: A Technical Case Report.

Letter: Sacroplasty Augmentation of Instrumented Pelvic Reconstruction After High Sacrectomy: A Technical Case Report.

Why Should Arteries from Expanded Criteria Donors Be Harvested?

Couture et al. investigated the early and late outcomes of patients with vascular graft infection treated by complete excision of the infected graft followed by infrarenal aortic repair using a cryopreserved arterial allograft (CAA).1 According to previously published similar series, they showed that the main drawbacks of CAA were allograft related complications, including rupture, pseudo-aneurysm, tear or collateral bleeding, and thrombosis or stenosis, leading to high CAA related re-intervention rates.

Results of cryopreserved arterial allograft replacement for thoracic and thoracoabdominal aortic infections

BackgroundPrimary and secondary thoracic aortic infections are rare but associated with high morbidity and mortality. There is currently no consensus on their optimal treatment. Arterial allografts have been shown to be resistant to bacterial colonization. Complete excision of infected material, especially synthetic grafts, combined with in situ aortic repair is considered the best treatment of abdominal aortic infections. The aim of this study was to assess the management of thoracic and thoracoabdominal aortic infections using arterial allografts. MethodsBetween January 2009 and December 2017, all patients with thoracic and thoracoabdominal aortic native or graft infections underwent complete excision of infected material and in situ arterial allografting. The end points were the early mortality and morbidity rates and early and late rates of reinfection, graft degeneration, and graft-related morbidity. ResultsThirty-five patients with a mean age of 65.6 ± 9.2 years were included. Twenty-one (60%) cases experienced graft infections and 14 (40%) experienced native aortic infections. Eight (22.8%) patients had visceral fistulas: 5 (14.4%) prosthetic-esophageal, 1 (2.8%) prosthetic-bronchial, 1 (2.8%) prosthetic-duodenal, and 1 (2.8%) native aortobronchial. In 12 (34.3%) cases, only the descending thoracic aorta was involved; in 23 (65.7%) cases, the thoracoabdominal aorta was involved.Fifteen (42.8%) patients died during the first month or before discharge: 5 of hemorrhage, 4 of multiorgan failure, 3 of ischemic colitis, 2 of pneumonia, and 1 of anastomotic disruption. Eleven (31.5%) patients required early revision surgery: 6 (17.1%) for nongraft-related hemorrhage, 3 (8.6%) for colectomy, 1 (2.9%) for proximal anastomotic disruption, and 1 (2.9%) for tamponade. One (2.9%) patient who died before discharge experienced paraplegia. One (2.9%) patient experienced stroke. Six (17.1%) patients required postoperative dialysis. Among them, four died before discharge. The mean length of stay in the intensive care unit was 11 ± 10.5 days; the mean length of hospital stay was 32 ± 14 days.During a mean follow-up of 32.3 ± 23.7 months, three allograft-related complications occurred in survivors (15% of late survivors): one proximal and one distal false aneurysm with no evidence of reinfection and one allograft-enteric fistula. The 1-year and 2-year survival rates were 49.3% and 42.5%, respectively. ConclusionsAlthough rare, aortic infections are highly challenging. Surgical management includes complete excision of infected tissues or grafts. Allografts offer a promising solution to aortic graft infection because they appear to resist reinfection; however, the grafts must be observed indefinitely because of the risk of late graft complications.

Solid-organ transplant surgeries in era of COVID-19 pandemic: How to go about it?

Solid-organ transplant surgeries in era of COVID-19 pandemic: How to go about it?

Treatment of benign and borderline bone tumors with combined curettage and bone defect reconstruction.

The management of bone defects following simple curettage of bone tumors is controversial and in light of the numerous emerging substitutes for bone grafts, we wished to review and report our experience with the use of cancellous allograft bone in the treatment of benign and borderline bone tumors. We reviewed the medical records of 164 consecutive patients with benign or borderline bone tumors treated with simple curettage at our orthopedic oncology center between 2009 and 2013. Postoperative radiological changes were evaluated by a modified Neer's classification in defects that were subsequently reconstructed with allograft bone ( n = 133). Simple curettage with subsequent defect filling using allograft bone was the surgical procedure performed in the majority of our patients (81%) and was associated with a low overall 2.5-year local recurrence (LR; 9.8%) and complication rate (7.5%). The radiological appearance of the grafted defects was deemed satisfactory in 85% of cases, with signs of either complete or partial healing present 6-12 months postoperatively. With respect to pathology, we found high rates of LR in giant cell tumors (GCTs) of bone, simple cysts (SCs) in children, and preexisting local recurrent disease. We did not observe any allograft-related complications. Simple curettage and bone defect reconstruction with bone allograft is a sufficient treatment for most benign bone lesions and is associated with a low complication rate. For high-risk entities, such as GCTs of bone, SCs in children, and recurrent disease, additional adjuvant treatment could be considered to avoid LR.

Twenty-year experience with cryopreserved arterial allografts for vascular infections.

The aim of this study was to analyse outcomes over 2 decades using cryopreserved vascular allografts to treat vascular infection. We conducted a retrospective study of patients identified from our institutional database who were treated for primary or secondary vascular infection using implanted allografts. Between October 1992 and May 2014, 54 patients underwent surgery for vascular infection out of 118 patients implanted with cryopreserved vascular allografts. The 52 patients for whom we had full information form the basis of the study with a 96% follow-up. The average age was 64 ± 11 years; 87% were men; 65% had previous vascular surgery; 19% had emergency operations. A total of 75% of the patients had aortoiliofemoral infections. Five patients underwent surgery with cardiopulmonary bypass. Fifty percent required more than 1 allograft and 15% had concomitant procedures. Seventy-three percent (38/52) of specimen cultures yielded positive results with polymicrobial flora in 29%. Surgical specimens most frequently grew coagulase-negative staphylococci. The early postoperative reoperation rate was 15% for allograft-related complications. There were 20 (38%) early deaths, including deaths of acute myocardial infarction, anastomosis rupture and persistent sepsis and shock. Uncontrolled infection leading to septic shock and multiple organ failure was the cause of death in 50% of the cases. The mean duration of freedom from allograft reintervention was 12.2 years. The mean duration of freedom from allograft occlusion or limb loss was 12.1 years [95% confidence interval (CI) 9.9-14.4]. Of the 32 surviving patients, we had patency information for 66% obtained by angiography or computed tomography. The mean survival for the cohort was 5.9 years (95% CI 3.9-7.8). Mean freedom from cardiovascular infection-related death was 9.3 years (95% CI 7.2-11.4). Allografts can be indicated for treatment of primary/secondary infection and have remarkable results in multimorbid patients. Patients with vascular infection have a high-risk profile, around 40% mortality during the first 6 months, with reduction in overall mortality thereafter. We believe that allografts may play a role in the surgical treatment of vascular infection.

Late Fate of Cryopreserved Arterial Allografts

Initial enthusiasm for use of cryopreserved arterial allografts was subsequently tempered by suboptimal long-term outcome. Thrombosis, anastomotic pseudo-aneurysm, allograft disruption, aneurysmal degeneration, recurrent intestinal fistulization, and persistent infection are commonly reported in series with long-term follow-up. The authors reviewed their experience over the past 15 years with the use of cryopreserved arterial allografts as a vascular substitute for vascular prosthetic infection or for primary arterial infection, to investigate allograft-related complications. A retrospective analysis of prospectively collected data was conducted for 103 cryopreserved arterial allografts inserted in 96 patients between July 2000 and July 2015. There were 78 patients with infected vascular prosthesis (IVP), nine patients with an aorto-enteric fistula (AEF), and nine patients with primary arterial infection (PAI). The in-hospital mortality was eight out of 78 (9%) IVP patients, three out of nine AEF patients, and zero out of nine PAI patients. Median follow-up was 49 months. Allograft-related re-interventions were necessary in 29% of the patients with IVP and four of the patients with AEF, but none of the patients with PAI. Five-year survival for the IVP, AEF, and PAI patients was 53%, 44%, and 90%, respectively. This series highlights some shortcomings of cryopreserved arterial allografts in the long term, including suboptimal outcome-results and shortage of material. The authors discuss the allograft-related complications and suggest some tricks to minimize their risk.

Long-term-management of organ transplant recipients

Due to advances in immunosuppressive therapy and surgical techniques, survival rates after solid organ transplantation have constantly improved over the last decades. In long-term care after transplantation, physicians need to focus as much on diagnosis and treatment of allograft-related complications as they should consider comorbidities and evaluate risk-factors and adverse events of immunosuppressive agents to prevent secondary diseases. In particular, cardiovascular and metabolic diseases, malignancy and infection play a major role in long-term survival. Therefore, screening of organ transplant recipients in regard to these complications and adverse events is a crucial part of follow up in these patients.

Comparison of Fusion Rates between Glycerol-Preserved and Frozen Composite Allografts in Cervical Fusion.

Background. This retrospective, two cohort series study was designed to compare a room temperature, glycerol-preserved composite pinned bone allograft (G-CPBA) with the same graft type provided in a frozen state (F-CPBA) for use as a cervical interbody spacer in anterior cervical discectomy and fusion (ACDF). Methods. A comprehensive chart review was performed for 67 sequential patients that received either a F-CPBA or a G-CPBA and had at least one-year follow-up. Twenty-eight patients had received G-CPBA grafts and 37 patients had received F-CPBA grafts. Two additional 2-level patients had received one of each type of grafts. Results. At 3 months, 45.3% (29 of 64) of glycerol-preserved and 41.4% (29 of 70) of frozen allografts, respectively, were considered to be fused radiographically. At 12 months, 100% of both treatment groups (41 glycerol-preserved and 45 frozen) were considered fused. Fusion rates for G-CPBA were statistically similar to F-CPBA at both 3 and 12 months (P = 0.6535 and >0.999, resp.). There were no allograft related complications in either treatment group. Conclusions. 100% fusion rates were attained by both treatment groups at 12 months and were similar at short-term follow-up for all comparable levels. Level of Evidence. Level of evidence is III.

Gene Therapy to Enhance Allograft Incorporation After Host Tissue Irradiation

Structural bone allografts are used to reconstruct large skeletal defects after tumor surgery. Although allograft-related complications are declining, the use of perioperative radiation therapy is associated with a poorer outcome. Recently, BMP-2 levels in the host bed were reportedly diminished after exposure to radiation doses consistent with those used perioperatively to treat musculoskeletal sarcoma. Reintroduction of this osteogenic protein may circumvent the deleterious effects of preoperative radiation on allograft incorporation. We introduced a novel polymeric BMP-2 gene delivery system into the host-allograft junctions at the time of transplantation in an ovine tibial defect model with or without preoperative exposure to 50 Gy radiation. After 4 months, we noted no radiographic or histologic improvements in allograft incorporation after preoperative radiation and BMP-2 reintroduction; however, 50 Gy radiation was associated with increased porosity in the interface regions and poorer radiographic healing. We identified no BMP2-expressing cells or protein in the interface at the study end point, suggesting the polymeric gene delivery system was unable to promote extended expression of the protein or induce a healing response. Although gene therapy may hold promise as a novel technique to improve allograft incorporation, our data do not support that contention with the current approach.

352: Controlled Ventilation High Resolution Computed Tomography, Pulmonary Function Testing, and Transbronchial/Open Lung Biopsy for the Detection of Allograft-Related Complications Following Infant Lung Transplantation

352: Controlled Ventilation High Resolution Computed Tomography, Pulmonary Function Testing, and Transbronchial/Open Lung Biopsy for the Detection of Allograft-Related Complications Following Infant Lung Transplantation

Aortic Graft Infections: Treatment With Arterial Allograft

Since its reintroduction by Kieffer in 1991, many authors have used arterial allografts for surgical management of vascular prosthetic graft infection. During a decade, 25 patients with aortic graft infection were treated using in situ revascularization with arterial allograft. There were 23 male and 2 female patients of mean age of 65.7 ± 8.8 years (range, 43–78). Antibiotic therapy was administered for a mean time of 26 ± 5 days (range, 21–45) in the postoperative period. The mean follow-up time was 2.3 ± 3 years (range, 22 days–8.7 years). The mean in-hospital postoperative stay was 29.6 ± 14 days (range, 9–68). An aorto-enteric fistula (AEF) was present in 11 patients (44%), producing gastrointestinal bleeding. The overall mortality rate was 13 of 23 (56.5%) patients. The allograft-related mortality rate was 5 of 23 (22%). The overall allograft-complicated patient rate was 15 of 23 (65%); we observed 18 allograft ruptures in 12 patients and 8 allograft thromboses in 6 patients. The overall amputation rate was 8.7% (2 of 23). Age of the recipient older than 69 years ( P = .02), positive preoperative marked-leukocyte scanning ( P = .04), and persistent postoperative leukocytosis ( P = .03) were significant variables associated with an increased risk of allograft-related complications. The use of arterial allografts for aortic graft infections represents an interesting alternative for the treatment of graft infection. Nevertheless, there are some problems related to the durability of this type of graft, which can still be considered as a “bridge transplant.”

Experience with cryopreserved arterial allografts in the treatment of prosthetic graft infections

The authors present a retrospective study on 30 patients with prosthetic graft infection. Included are 25 patients with aortic graft infection, three with infection of a femorodistal bypass and two with infected axillofemoral grafts. There were 23 isolated primary prosthetic graft infections and seven aorto-enteric fistulas. Treatment consisted of graft excision and replacement with cryopreserved arterial homografts, harvested from brain-death multi-organ donors. The in situ technique was used in 27 cases. Eight patients died postoperatively and two deaths were from allograft related complications. The operative mortality rate was 11% for isolated aortic graft sepsis and the early limb salvage rate was 100%. Persistent or recurrent infection was noted in two cases. The mean follow-up of the series was 24.5 months and occlusive complications occurred in five patients (23%), which resulted in two major amputations. Serial CT scans showed abnormalities in six of the 22 survivors, all of them related to the aortic segment of the allograft. It is concluded that in situ reconstruction with cryopreserved arterial allografts represents an acceptable alternative, especially in the treatment of isolated aortic graft sepsis. Continued follow-up towards late deterioration and/or occlusive complications remains mandatory.

In situ allograft replacement of infected infrarenal aortic prosthetic grafts: Results in forty-three patients

Purpose: Dissatisfaction with conventional methods of treatment of infected infrarenal aortic prosthetic grafts and excellent long-term results reported by heart surgeons after allograft replacement for management of infections involving the ascending aorta have prompted us to investigate allograft replacement in the management of arterial infections.Methods: From October 1988 to April 1992, 43 consecutive patients with infected infrarenal aortic prosthetic grafts underwent in situ replacement with preserved allografts obtained from cadavers as part of a program to retrieve multiorgan transplant tissue. Thirty-four patients had isolated prosthetic infections, whereas nine had aortoenteric fistulas. One patient had a concomitant below-knee amputation for septic arthritis of the ankle as a result of septic emboli. Nineteen patients had nonvascular-associated procedures, including 17 intestinal procedures.Results: Five patients (12%) died after operation: four of general causes and one of rupture of the native aorta as a result of persistent infection. Three patients successfully underwent repeat operation for allograft-related complications (one case each of occlusion, septic rupture, and graft-enteric fistula). All surviving patients were discharged after control angiography showed patent allografts. Two patients were unavailable for follow-up. The other 36 patients have been monitored with serial duplex and computed tomography scanning for a mean follow-up of 13.8 months (range 1 to 42 months). There were four late deaths: three were unrelated to the vascular operation, and one may have been caused by late persistent or recurrent infection. Nine patients (26%) have had pathologic changes in the allograft, with three (9%) requiring repeat operation. There were no early or late postoperative amputations in the entire series.Conclusions: Although complete protection against persistent or recurrent infection has not been achieved and late deterioration may be expected, in situ allograft replacement seems to be a major advance in the management of infected infrarenal aortic prosthetic grafts.