Technical Variant Liver Transplant Utilization for Pediatric Recipients: Equal Graft Survival to Whole Liver Transplants and Promotion of Timely Transplantation Only When Performed at High-volume Centers

BACKGROUND

Technical variant liver transplantation (TVLT) is a strategy to mitigate persistent pediatric waitlist mortality in the United States, although its implementation remains stagnant. This study investigated the relationship between TVLT utilization, transplant center volume, and graft survival.

METHODS

Pediatric liver transplant recipients from 2010 to 2020 (n = 5208) were analyzed using the Scientific Registry of Transplant Recipients database. Transplant centers were categorized according to the average number of pediatric liver transplants performed per year (high-volume, ≥5; low-volume, <5). Graft survival rates were compared using Kaplan-Meier curves and log-rank tests. Cox proportional hazards models were used to identify predictors of graft failure.

RESULTS

High-volume centers demonstrated equivalent whole liver transplant and TVLT graft survival ( P = 0.057) and significantly improved TVLT graft survival compared with low-volume centers ( P < 0.001). Transplantation at a low-volume center was significantly associated with graft failure (adjusted hazard ratio, 1.6; 95% confidence interval, 1.14-2.24; P = 0.007 in patients <12 y old and 1.8; 95% confidence interval, 1.13-2.87; P = 0.013 in patients ≥12 y old). A subset of high-volume centers with a significantly higher rate of TVLT use demonstrated a 23% reduction in waitlist mortality.

CONCLUSIONS

Prompt transplantation with increased TVLT utilization at high-volume centers may reduce pediatric waitlist mortality without compromising graft survival.

Impact of Pretransplant Donor BK Viruria in Kidney Transplant Recipients

BACKGROUND

BK virus (BKV) is a significant cause of nephropathy in kidney transplantation. The goal of this study was to characterize the course and source of BKV in kidney transplant recipients.

METHODS

We prospectively collected pretransplant plasma and urine samples from living and deceased kidney donors and performed BKV polymerase chain reaction (PCR) and immunoglobulin G (IgG) testing on pretransplant and serially collected posttransplant samples in kidney transplant recipients.

RESULTS

Among deceased donors, 8.1% (17/208) had detectable BKV DNA in urine prior to organ procurement. BK viruria was observed in 15.4% (6/39) of living donors and 8.5% (4/47) of deceased donors of recipients at our institution (P = .50). BKV VP1 sequencing revealed identical virus between donor-recipient pairs to suggest donor transmission of virus. Recipients of BK viruric donors were more likely to develop BK viruria (66.6% vs 7.8%; P < .001) and viremia (66.6% vs 8.9%; P < .001) with a shorter time to onset (log-rank test, P < .001). Though donor BKV IgG titers were higher in recipients who developed BK viremia, pretransplant donor, recipient, and combined donor/recipient serology status was not associated with BK viremia (P = .31, P = .75, and P = .51, respectively).

CONCLUSIONS

Donor BK viruria is associated with early BK viruria and viremia in kidney transplant recipients. BKV PCR testing of donor urine may be useful in identifying recipients at risk for BKV complications.

Eliminating international normalized ratio threshold for transfusion in pediatric patients with acute liver failure

INTRODUCTION

Transfusion protocols are not well-studied for pediatric patients with acute liver failure (ALF). This study evaluates the utility of an international normalized ratio (INR)-based transfusion threshold for these patients.

METHODS

Forty-four ALF pediatric patients from 2009 to 2018 were reviewed and divided into two groups: (a) a threshold group including patients between 2009 and 2015 who were transfused for an INR above 3.0, per institutional policy (n = 30), and (b) a post-threshold group including patients after 2015 through 2018 who were transfused based on clinical judgment (n = 14). Preoperative INRs, preoperative transfusions, intraoperative transfusions, early reoperation, renal function, graft function and deaths were compared.

RESULTS

Liver failure severity was similar between threshold and post-threshold groups. Threshold patients had a lower average INR prior to transplantation, 2.8 (range 1.8-3.8) vs 4.4 (range 2.1-9.0), respectively (P = .01). Twenty-six threshold patients (87%) received preoperative FFP compared with seven post-threshold patients (50%, P = .0088). Two threshold patients (7%) received preoperative cryoprecipitate compared with five post-threshold patients (36%, P = .014). The incidence of pre-transplant bleeding, operative transfusions, and 1-year patient and graft survival did not differ significantly.

CONCLUSION

Clinical judgment vs an INR-based threshold for transfusions did not increase perioperative complications in children with ALF.

Impact of the kidney allocation system on young pediatric recipients

The kidney allocation system (KAS) altered pediatric candidate prioritization. We determined KAS's impact on pediatric kidney recipients by examining delayed graft function (DGF) rates from 2010 to 2016. A propensity score-matched pediatric recipients pre- and post-KAS. A semiparametric decomposition analysis estimated the contributions of KAS-related changes in donor characteristics and dialysis time on DGF rate. The unadjusted odds of DGF were 69% higher post-KAS for young (<10 years at listing) recipients (N = 1153, P = .02) but were not significantly increased for older pediatric (10-17 years at listing) recipients (N = 2624, P = .48). Post-KAS, young recipients received significantly fewer pediatric (<18 years) donor kidneys (21% vs 32%, P < .01) and had longer median pretransplant dialysis time (603 vs 435 days, P < .01). After propensity score matching, post-KAS status increased the odds of DGF in young recipients 71% (OR 1.71, 95% CI 1.01-2.46). In decomposition analysis, 24% of the higher DGF rate post-KAS was attributable to donor characteristics and 19% to increased recipient dialysis time. In a confirmatory survival analysis, DGF was associated with a 2.2 times higher risk of graft failure (aHR2.28, 95% CI 1.46-3.54). In conclusion, KAS may lead to worse graft survival outcomes in children. Allocation changes should be considered.

The role of surgery in the treatment of stage III non—small-cell lung cancer

Stage III, locally advanced non-small-cell lung cancer represents an incredibly heterogeneous group of patients. The majority of patients are treated with curative intent, but optimal therapy is controversial and the role of surgery is not well defined. Consensus has shown that the majority of patients with IIIB disease are not amenable to resection. The exceptions are selected patients with tumor stage 4 (T4) by virtue of a satellite nodule or those with isolated invasion of the spine, superior sulcus, carina, or vena cava. Surgery is more widely used for stage IIIA disease. Patients with nodal stage 2 (N2) disease represent the largest population of patients in stage III. Increasing evidence supports the use of surgery as part of a multimodality approach for N2 disease. The impact of surgery is partially determined by the bulk of the mediastinal node involvement. Patients with micrometastatic disease and single-station nodal involvement have the greatest chance for cure, and surgery appears to play a significant role in their treatment. Patients with bulky multistation disease are frequently not amenable to complete resection and may be best approached with definitive chemotherapy and radiation. In addition, the ability to sterilize mediastinal lymph nodes with induction therapy correlates strongly with survival following resection, but the ideal induction regime that balances the safety and efficacy has yet to be determined.

Hospital ethics committees: a pediatric neurosurgical perspective

The Pediatric Neurosurgical Section of the American Association of Neurological Surgeons was polled regarding the status of hospital ethics committees. Twenty-four committees were identified in 74 pediatric neurosurgical centers in the United States. (Thirteen of these were formed between October 1983 and February 1984.) In addition, 21 are in the planning stages. Physicians predominate, with nurses, hospital administrators, the clergy, social workers, attorneys and lay persons usually represented. Functions include review of ethical and patient care decisions and providing counsel and support primarily to physicians and nurses. Rarely do committees make policy, determine prognosis or make final decisions regarding life-support systems. Approximately one case per year is reviewed. Committee formation frequently appears to be a crisis response to highly publicized pediatric cases and recent positions of the Department of Health and Human Services. Their purpose, construct, function and utilization raise serious questions as to their usefulness and necessity.

A novel protein complex distinct from mismatch repair binds thioguanylated DNA

To elucidate molecular mechanism(s) of cellular response to mercaptopurine, a widely used antileukemic agent, we assessed mercaptopurine (MP) sensitivity in mismatch repair (MMR) proficient and MMR deficient human acute lymphoblastic leukemia (ALL) cells. Sensitivity to thiopurine cytotoxicity was not dependent on MMR (i.e., MutSalpha) competence among six cell lines tested. Using electrophoretic mobility shift assay analysis, we found that the incubation of nuclear extracts from ALL cells with synthetic 34-mer DNA duplexes containing deoxythioguanosine (G(S)) within either G(S).T or G(S).C pairs, resulted in formation of a DNA-protein complex distinct from the DNA-MutSalpha complex and unaffected by ATP. Isolation and sequence analysis of proteins involved in this DNA-protein complex identified glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as a component. Western blot analysis of nuclear extracts from a panel of human lymphoblastic leukemia cell lines revealed markedly different basal levels of GAPDH in nuclei, which was significantly related to thiopurine sensitivity (p = 0.001). Confocal analysis revealed markedly different intracellular distribution of GAPDH between nucleus and cytosol in six human ALL cell lines. Redistribution of GAPDH from cytosol to nucleus was evident after MP treatment. These findings indicate that a new DNA-protein complex containing GAPDH and distinct from known MMR protein-DNA complexes binds directly to thioguanylated DNA, suggesting that this may act as a sensor of structural alterations in DNA and serve as an interface between these DNA modifications and apoptosis.

Repair of giant occipital encephaloceles with microcephaly secondary to massive brain herniation

Giant occipital encephaloceles rarely contain large amounts of neural tissue that cannot be replaced in the abnormally small calvarium. Resection of neural elements is therefore often necessary in order to accomplish a closure. A technique is described wherein an extracranial compartment is prepared utilizing fine tantalum mesh to enclose the neural contents. The mesh is attached to the periphery of the skull defect providing a rigid extracranial compartment for the encephalocele. As intracranial pressure increases, the calvarium is forced to expand. The tantalum mesh is gradually imbricated into the calvarium by daily digital compression. If ventriculomegaly occurs, an interval ventriculoperitoneal shunt is placed. The encephalocele repair is reopened and the tantalum is surgically imbricated at that time. This allows for a satisfactory cosmetic result with preservation of all neural elements.

Intracranial extension of nasal dermoids

Nasal dermoid cysts with intracranial extension have been thought to be a rare entity. Seven new cases of nasal dermoid cyst with intracranial involvement were treated from 1975 through 1982 by combined otolaryngological-neurosurgical management. Preoperative radiological studies were helpful in predicting intracranial extension in only three cases. The extracranial lesion was resected by the otolaryngologist using surgical hemoclips to tag the dermoid remnant entering the cranium. These hemoclips were a helpful landmark for the neurosurgeon when resecting the intracranial extension through a bifrontal craniotomy approach. In four cases, the dermoid cyst entered the cranium through a persistent foramen cecum and lay within the falx in association with a bifid crista galli. We think that this entity is more common than was previously appreciated. Patients with a diagnosis of nasal dermoid should undergo polytomography or computed tomography of the glabellar area. Even when all x-ray studies are negative, neurosurgical preoperative evaluation and operative standby should be obtained before the otolaryngologist attempts the resection of a nasal dermoid cyst.

Fluctuation of intracranial pressure associated with the cardiac cycle

Within the intensive care setting, a portable microcomputer system was used to extract three parameters from the intracranial pressure fluctuation associated with the cardiac cycle. One parameter, the mean of sampled intracranial pressure, was defined as the average value of pressure for a 1.08-second interval following the R wave of the electrocardiogram. Another parameter, the amplitude of intracranial pressure, was defined as the difference between the mean and the peak value of the sampled intracranial pressure for the interval considered. The third parameter, a latent interval, was defined as the time period between the occurrence of the R wave and the occurrence of the peak value of the subsequent intracranial pressure fluctuation. Six adults and one pediatric patient were monitored. Both the amplitude and the mean of sampled pressure tended to vary inversely with the latent interval. For the adult patients, the latent interval varied between 503 and 804 ms; the mean pressure ranged between 2.4 and 19.0 mm Hg and the amplitude pressure ranged between 0.6 and 7.2 mm Hg. The latent interval for the child was much shorter (ranging between 269 and 325 ms), and both the mean and the amplitude pressures were much higher (ranging between 38.4 and 57.3 mm Hg and 14.2 and 16.5 mm Hg, respectively). Statistical correlation between hourly pulse rates and the latent interval among the adult cases revealed little association (r = -0.20). For all patients considered, the correlation between the amplitude and the mean of sampled intracranial pressure was quite high, with an r value of +0.91. These reported observations support a conceptual model in which blood volume changes associated with the cardiac cycle occurring within the semirigid craniospinal sac are assumed to underlie the fluctuation of intracranial pressure.

Intracranial and extracranial neurogenic hamartoma

A case of neurogenic hamartoma involving the middle cranial fossa, nasopharynx, and left anterior cervical region and presenting at birth as an obstructive oropharyngeal mass is described. Special management included Gelfoam embolization of the vascular supply, control of airway and feeding, assessment of biological activity of the mass, and appropriate staging of the procedure with neurosurgical, head and neck surgical, and radiological support.

Retest reliability of the Halstead Impairment Index in a normal, a schizophrenic, and two samples of organic patients

In a 1974 study Matarazzo, et al. reported the test-retest reliability of the Halstead-Reitan Neuropsychological Battery for a sample of normal young men and a comparison group of older Ss with cerebrovascular disease. The present study extended this earlier one by addition of comparable test-retest findings from two additional comparison groups: a sample of chronic schizophrenic Ss and a sample of organic patients who underwent endarterectomy. Despite the lack of comparability across the four samples on many dimensions, including age and test-retest interval, the results again reveal a high degree of clinical as well as purely psychometric reliability for most of the tests in the neuropsychological battery and the additional suggestion for further research that the test-retest instability found for some of the Ss in the schizophrenic sample may, itself, hold promise of differential clinical significance in the diagnosis of a "schizophrenic" vs. "organic" process.

Percutaneous management of ventricular catheter obstruction. Technical note

check; A technique is described for placement of ventricular shunt catheters which allows later nonoperative relief of obstruction within the proximal catheter. Operative revision of occluded ventricular catheters may often be avoided by percutaneous aspiration and irrigation of foreign material, thus decreasing the morbidity associated with shunt revision.

Cystometry as an adjunct in the evaluation of lumbar disc syndromes

✓ One hundred patients with the provisional diagnosis of nerve root compression in the lumbar spine were subjected to routine bladder evaluation by cystometry in addition to the standard somatic neurological examination. Eighty-three were found to have cystometrograms characteristic of bladder hypofunction. Residual urine was found in 20% of the 100 patients. By contrast, the examination of the somatic nervous system disclosed sensory deficits in 36%, weakness in 59%, reflex alterations in 66%, and positive sciatic-stretch tests in 69%. Almost all cystometric studies (96%) became normal after successful surgical or conservative therapy. It is concluded that occult bladder dysfunction is a major manifestation of lumbar nerve root compression. The neurophysiological mechanisms involved are discussed in detail.