Dural repair using acellular human dermis: experience with 200 cases: technique assessment

OBJECTIVE: Many craniotomies require a watertight dural closure. When primary dural repair is not possible, a graft is necessary. Autograft material is not always easily accessible or available, necessitating the use of other material. We performed 200 craniotomies using an acellular human dermal graft (AlloDerm; LifeCell Corp., The Woodlands, TX) to determine its suitability as a dural substitute. METHODS: From June 1996 through March 1998, all patients at Allegheny General Hospital who required a dural substitute graft and in whom autograft harvest was impractical or impossible received the acellular dermal autograft. The running suture technique was used to form a watertight seal. RESULTS: After follow-up for a minimum of 1 year, seven patients have required subsequent surgery. Three patients developed cerebrospinal fluid leaks that were repaired without removing the dermal graft. Four patients developed wound infections that required debridement. In each patient, the graft seemed to be uninvolved in the infectious process and was left in place. The patients were administered antibiotics postoperatively, and there have been no recurrent infections. No adhesion formation or scarring was noted around or underneath the graft in any patient. CONCLUSION: AlloDerm is a reasonable alternative to the available dural graft materials. Its handling characteristics are similar to those of dura, it is biologically inert, and it does not produce adhesion formation.     

Decompression alone versus decompression with fusion in patients with lumbar spinal stenosis with degenerative spondylolisthesis: a systematic review and meta-analysis

Introduction

Surgical decompression is standard care in the treatment of degenerative spondylolisthesis in patients with symptomatic lumbar spinal stenosis, but there remains controversy over the benefits of adding fusion. The persistent lack of consensus on this matter and the availability of new data warrants a contemporary systematic review and meta-analysis of the literature.

Methods

Multiple online databases were systematically searched up to October 2022 for randomized controlled trials (RCTs) and prospective studies comparing outcomes of decompression alone versus decompression with fusion for lumbar spinal stenosis in patients with degenerative spondylolisthesis. Primary outcome was the Oswestry Disability Index. Secondary outcomes included leg and back pain, surgical outcomes, and radiological outcomes. Pooled effect estimates were calculated and presented as mean differences (MD) with their 95% confidence intervals (CI) at two-year follow-up.

Results

Of the identified 2403 studies, eventually five RCTs and two prospective studies were included. Overall, most studies had a low or unclear risk of selection bias and most studies were focused on low grade degenerative spondylolisthesis. All patient-reported outcomes showed low statistical heterogeneity. Overall, there was high-quality evidence suggesting no difference in functionality at two years of follow-up (MD − 0.31, 95% CI − 3.81 to 3.19). Furthermore, there was high-quality evidence of no difference in leg pain (MD − 1.79, 95% CI − 5.08 to 1.50) or back pain (MD − 2.54, 95% CI − 6.76 to 1.67) between patients undergoing decompression vs. decompression with fusion. Pooled surgical outcomes showed less blood loss after decompression only, shorter length of hospital stay, and a similar reoperation rate compared to decompression with fusion.

Conclusion

Based on the current literature, there is high-quality evidence of no difference in functionality after decompression alone compared to decompression with fusion in patients with degenerative lumbar spondylolisthesis at 2 years of follow-up. Further studies should focus on long-term comparative outcomes, health economic evaluations, and identifying those patients that may benefit more from decompression with fusion instead of decompression alone. This review was registered at Prospero (CRD42021291603).

     

Kinetics of primary tumor regression with chemotherapy: Implications for the timing of surgery

Purpose: The kinetics of tumor regression during administration of chemotherapy has relevance to the timing of surgery. The aim of this study was characterization of the time course of primary tumor regression in initially unresectable rhabdomyosarcoma, hepatoblastoma, and neuroblastoma patients. We also estimated the total cell number in the primary tumor at diagnosis. Methods: Tumor volumes of 24 pediatric patients with either unresectable rhabdomyosarcoma, hepatoblastoma, or neuroblastoma were determined by using computerized three-dimensional reconstruction from serial computed tomography (CT) scans during chemotherapy. Cell densities were calculated by counting cell numbers in high-power fields and dividing by area and section thickness. Cell number at diagnosis was then calculated. Results: Median tumor volumes at diagnosis were 175 cc, 748 cc, and 738 cc for rhabdomyosarcoma, neuroblastoma, and hepatoblastoma, respectively. The median tumor cell counts were 31, 68, and 59 × 10¹⁰ cells/tumor for rhabdomyosarcoma, neuroblastoma, and hepatoblastoma, respectively. The tumor regression was most rapid during the first two cycles, and little change in volume was observed after three cycles. Conclusion: Rapid initial reduction in primary tumor volume with chemotherapy was observed in rhabdomyosarcoma, neuroblastoma, and hepatoblastoma. These data suggest that second-look resection may be feasible after two to three cycles of chemotherapy. This hypothesis may be tested by randomizing the timing of second-look surgical intervention.Presented at the 48th Annual Cancer Symposium of The Society of Surgical Oncology, Boston, Massachusetts, March 23–26, 1995.     

The effects of serum depletion and dexamethasone on growth and differentiation of human neuroblastoma cell lines

BACKGROUND/PURPOSE: Neuroblastoma is the most solid common extracranial malignancy in childhood. Despite multimodality treatment, high-risk disease continues to carry a poor prognosis. Glucocorticoids have been shown previously to induce differentiation in murine neuroblastoma cell lines, but no such effect has been documented in human neuroblastoma cells. Glucocorticoids are known to be active in the differentiation process of the neural crest. These studies describe the effects of dexamethasone on 6 human neuroblastoma cell lines. METHODS: Dexamethasone was added to cultured neuroblastoma cell lines (LA1-5S, LA1-15N, BE[2]S, BE[2]N, SH-EP-1, SH-SY5Y) maintained in media supplemented with either normal serum or charcoal-depleted serum. Proliferation assays were performed, and flow cytometry was used to assess alterations in cell cycle. Cells were closely monitored for morphological changes with serial phase-contrast microscopy. Immunohistochemistry (3F8, NF-1, TRK-A) of cultured cells was used to evaluate differentiation. Glucocorticoid receptor levels was assessed using immunoblotting. RESULTS: Dexamethasone decreased the rate of cellular proliferation in both standard and charcoal-depleted conditions. Flow cytometry showed a G1 accumulation. Increased expression of the differentiation-associated antigens was found in cells cultured in charcoal-depleted media, and a further augmentation was seen with the addition of dexamethasone. In standard media, dexamethasone had no detectable effect on the expression of these antigens. Glucocorticoid receptor expression was found to be comparable in all cell lines. CONCLUSIONS: Human neuroblastoma cells are sensitive to the differentiating effects of dexamethasone in an environment of charcoal-depleted serum. This phenomenon may be caused by the existence of growth and mitogenic factors in serum that are inhibiting differentiation.