Colonic expression of calcium transporter TRPV6 is regulated by dietary sodium butyrate.

Dietary fibers have been shown to increase the intestinal absorption of calcium (Ca2+) and magnesium (Mg2+). However, the mechanisms that explain the enhanced electrolyte absorption remain unknown. Therefore, this study aims to investigate the short-term and long-term effects of 5% (w/w) sodium butyrate (Na-butyrate), an important end-metabolite of bacterial fermentation of dietary fibers, on Ca2+ and Mg2+ homeostasis in mice. Serum Ca2+ levels were only significantly increased in mice treated with Na-butyrate for 1 day. This was associated with a twofold increase in the mRNA expression levels of Trpv6 in the proximal and distal colon. Contrary, Na-butyrate did not affect serum Mg2+ concentrations at either of the intervention periods. However, we observed a reduction in urinary Mg2+ excretion, although not significantly, after 1 day of treatment. A significant reduction of 2.5-fold in urinary Mg2+ excretion was observed after 14 days of treatment. Indeed, 14-day Na-butyrate supplementation increased colonic Trpm7 expression by 1.2-fold compared to control mice. In conclusion, short-term Na-butyrate supplementation increases serum Ca2+ levels in mice. This was associated with increased mRNA expression levels of Trpv6 in the colon, suggesting that Na-butyrate regulates the expression of genes involved in active intestinal Ca2+ absorption.

High frequency of inactivating tetraspanin C D37 mutations in diffuse large B-cell lymphoma at immune-privileged sites.

Tetraspanin CD37 is predominantly expressed on the cell surface of mature B lymphocytes and is currently being studied as novel therapeutic target for B-cell lymphoma. Recently, we demonstrated that loss of CD37 induces spontaneous B-cell lymphoma in Cd37-knockout mice and correlates with inferior survival in patients with diffuse large B-cell lymphoma (DLBCL). Here, CD37 mutation analysis was performed in a cohort of 137 primary DLBCL samples, including 44 primary immune-privileged site-associated DLBCL (IP-DLBCL) samples originating in the testis or central nervous system. CD37 mutations were exclusively identified in IP-DLBCL cases (10/44, 23%) but absent in non-IP-DLBCL cases. The aberrations included 10 missense mutations, 1 deletion, and 3 splice-site CD37 mutations. Modeling and functional analysis of CD37 missense mutations revealed loss of function by impaired CD37 protein expression at the plasma membrane of human lymphoma B cells. This study provides novel insight into the molecular pathogenesis of IP-DLBCL and indicates that anti-CD37 therapies will be more beneficial for DLBCL patients without CD37 mutations.

Pretreatment ADC is not a prognostic factor for local recurrences in head and neck squamous cell carcinoma when clinical T-stage is known.

OBJECTIVES: Pretreatment identification of radio-insensitive head and neck squamous cell carcinomas (HNSCC) would affect treatment modality selection. The apparent diffusion coefficient (ADC) of a tumor could be a predictor of local recurrence. However, little is known about its prognostic value next to known factors such as clinical T-stage. The aim of the present study is to determine the added value of pretreatment ADC to clinical T-stage as a prognostic factor for local recurrence. METHODS: This retrospective cohort study included 217 patients with HNSCC treated with (chemo)radiotherapy between April 2009 and December 2015. All patients underwent diffusion-weighted MRI prior to treatment. Median ADC values of all tumors were obtained using a semi-automatic delineation method. Univariate models containing ADC and T-stage were compared with a multivariable model containing both variables. RESULTS: Fifty-eight patients experienced a local recurrence within 3 years. On average, the ADC value in the group of patients with a recurrence was 1.01 versus 1.00 (10-3 mm2/s) in the group without a recurrence. Univariate analysis showed no significant association between tumor ADC and local recurrence within 3 years after (chemo)radiotherapy (p = 0.09). Cox regression showed that clinical T-stage was an independent predictor of local recurrence and adding ADC to the model did not increase its performance. CONCLUSION: Pretreatment ADC has no added value as a prognostic factor for local recurrence to clinical T-stage. KEY POINTS: • Pretreatment identification of head and neck squamous cell carcinoma patients who do not benefit from (chemo)radiotherapy could improve personalized cancer care. • The apparent diffusion coefficient (ADC) obtained from diffusion-weighted MRI has been reported to be a prognostic factor for local recurrence. • In this study, ADC has no added value as a prognostic factor compared with clinical T-stage.

Influence of FDG-PET on primary nodal target volume definition for head and neck carcinomas.

BACKGROUND: The role of 2-[18F]-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in routine diagnostic staging remains controversial. In case of discordance between FDG-PET and CT, a compromise has to be made between the risk of false positive FDG-PET and the risk of delaying appropriate salvage intervention. Second, with intensity modulated radiation therapy (IMRT), smaller radiation fields allow tissue sparing, but could also lead to more marginal failures. METHODS: We retrospectively studied 283 patients with head and neck carcinoma scheduled for radiotherapy between 2002 and 2010. We analyzed the influence of FDG-PET/CT versus CT alone on defining nodal target volume definition and evaluated its long-term clinical results. Second, the location of nodal recurrences was related to the radiation regional dose distribution. RESULTS: In 92 patients, CT and FDG-PET, performed in mold, showed discordant results. In 33%, nodal staging was altered by FDG-PET. In 24%, FDG-PET also led to an alteration in nodal treatment, including a nodal upstage of 18% and downstage of 6%. In eight of these 92 patients, a regional recurrence occurred. Only two patients had a recurrence in the discordant node on FDG-PET and CT and both received a boost (high dose radiation). CONCLUSION: These results support the complementary value of FDG-PET/CT compared to CT alone in defining nodal target volume definition for radiotherapy of head and neck cancer.

The accuracy of target delineation in laryngeal and hypopharyngeal cancer.

BACKGROUND AND PURPOSE: To determine the spatial correspondence between the gross tumor volume (GTV) delineated on computer tomography (CT) and the actual tumor on histopathology. MATERIAL AND METHODS: Sixteen patients with T3 or T4 laryngeal or hypopharyngeal cancer underwent a CT scan before total laryngectomy. The GTV was delineated on CT by three independent observers and by consensus between the three observers. After surgery, whole-mount hematoxylin-eosin stained (H&E) sections were obtained. One pathologist delineated the tumor in the H&E sections (tumorH&E). The reconstructed specimen was registered to the CT scan in order to compare the GTV to the tumorH&E in three dimensions. The overlap between the GTV and the tumorH&E was calculated and the distance between the volumes was determined. RESULTS: Tumor tissue was delineated in 203 of 516 H&E sections. For 14 patients a detailed analysis could be performed. The GTV volume was on average 1.7 times larger than the volume of the tumorH&E. The mean coverage of the tumorH&E by the consensus GTV was 88%. tumorH&E tissue was found at 1.6 mm to 12.9 mm distance outside the GTV depending on observer and patient. CONCLUSIONS: GTVs delineated on CT for laryngeal and hypopharyngeal cancer were 1.7 times larger than the tumor. Complete coverage of the tumor by the GTV was, however, not obtained.

Diffusion-weighted MR imaging in laryngeal and hypopharyngeal carcinoma: association between apparent diffusion coefficient and histologic findings.

PURPOSE: To investigate the relationship between the histologic characteristics of head and neck squamous cell carcinoma and apparent diffusion coefficient (ADC) at diffusion-weighted magnetic resonance (MR) imaging. MATERIALS AND METHODS: The institutional ethics committee approved this study and waived informed consent. In head and neck squamous cell carcinoma, local failure after chemotherapy and/or radiation therapy correlates with pretreatment ADC. However, the histopathologic basis of this correlation remains unclear. In this study, 16 patients with head and neck squamous cell carcinoma were enrolled (median age, 60 years; range, 49-78 years). Before undergoing total laryngectomy, patients underwent 1.5-T diffusion-weighted MR imaging. After resection, whole-mount hematoxylin-eosin-stained sections were registered to the MR images. Cellular density; nuclear, cytoplasmic, and stromal area; and nuclear-cytoplasmic ratio within the tumor were calculated by using image-based segmentation on four consecutive slices. Mean ADC of the corresponding tumor region was calculated. Spearman correlations between ADC and histologic characteristics were calculated. RESULTS: ADC was significantly and inversely correlated with cell density (n = 16, r = -0.57, P = .02), nuclear area (n = 12, r = -0.64, P = .03), and nuclear-cytoplasmic ratio (n = 12, r = -0.77, P ≤ .01). ADC was significantly and positively correlated with percentage area of stroma (n = 12, r = 0.69, P = .01). Additionally, the percentage area of stroma was strongly interdependent with the percentage area of nuclei (n = 12, r = -0.97, P ≤ .01). CONCLUSION: ADC was significantly correlated with cellularity, stromal component, and nuclear-cytoplasmic ratio. The positive correlation of ADC and stromal component suggests that the poor prognostic value of high pretreatment ADC might partly be attributed to the tumor-stroma component, a known predictor of local failure.

Use of the 2-µm continuous wave thulium laser for the resection of oral squamous cell carcinomas does not impair pathological assessment.

BACKGROUND AND OBJECTIVE: Current resection modalities for oral squamous cell carcinomas (OSCC) vary from cold steel over CO2 laser to monopolar electro-surgery (MO). We compared thulium laser (TL) as a new modality with MO with regards to pathological assessment. STUDY DESIGN/MATERIALS AND METHODS: Forty-two patients who were treated for OSCC by either TL or MO were included. All resected specimens were assessed with special attention to margin interpretation and thermal damage. RESULTS: Depth of thermal damage ranged from 1.0 to 3.5 mm in the TL group compared to 1.0-4.0 mm in the MO group without interfering with the pathological assessment. The percentage of positive margin resections was three times higher in the MO group compared with the TL group. CONCLUSIONS: This study shows resections done by TL do not impair pathological assessment when compared to MO resections.

Long-term oncological follow-up after mold-based pulsed dose rate brachytherapy for early stage squamous cell carcinoma of the nasal vestibule: A single center experience of 68 patients over a 17-year period.

PURPOSE: Cancer of the nasal vestibule is a rare type of malignancy constituting less than one percent of all head and neck cancers. These tumors are typically diagnosed at an early stage. Both surgery and radiotherapy provide excellent oncological results, but esthetic results are better after radiotherapy. The aim of this study was to evaluate the long-term oncological follow-up after brachytherapy for early stage squamous cell carcinoma of the nasal vestibule. METHODS AND MATERIALS: Retrospective analysis of patients with carcinoma of the nasal vestibule who were treated with primary brachytherapy in the Utrecht University Medical Center. RESULTS: In this single center experience over a 17-year period 68 patients with early stage squamous cell carcinoma of the nasal vestibule were treated with brachytherapy. Two patients had lymph node metastases at first clinical presentation. Median follow-up duration was 46.5 months. Five-year locoregional recurrence-free survival, disease-specific survival, and overall survival were 91.1%, 96.1%, and 66.2%, respectively. All recurrences occurred within the first 3 years of follow-up. CONCLUSIONS: Brachytherapy offers excellent oncological outcomes and is a safe and effective treatment for early stage carcinoma of the nasal vestibule. Recurrences typically occur within 3 years after treatment.

Diagnostic and Treatment-Related Challenges in Sinonasal Teratocarcinosarcoma: A Report of Three Cases.

Background: Sinonasal teratocarcinosarcoma is a rare, aggressive malignancy located almost exclusively in the nasal cavity, paranasal sinuses, or anterior skull base. Histopathological diagnosis can be challenging due to the heterogeneous composition. Methods: Retrospective analysis of 3 patients with sinonasal teratocarcinosarcoma diagnosed and treated at the University Medical Center Utrecht was conducted. Results: Patients presented with nasal obstruction, epistaxis, headaches, or behavioral changes. All three patients had locally advanced disease, and one had lymph node metastases. Two patients underwent surgery followed by radiotherapy, and one underwent neoadjuvant chemotherapy followed by surgery. The follow-up duration ranged from 3 to 32 months. All three patients died due to progression of their disease. Conclusion: Sinonasal teratocarcinosarcoma is characterized by rapid, aggressive local expansion. The prognosis is poor due to a high risk of metastases and locally recurrent disease. Multimodality treatment consisting of surgery, followed by (chemo)-radiotherapy, is essential for optimizing outcomes. Neoadjuvant therapy offers a promising treatment option.

IRF8 is a transcriptional activator of CD37 expression in diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) represents the most common form of non-Hodgkin lymphoma (NHL) that is still incurable in a large fraction of patients. Tetraspanin CD37 is highly expressed on mature B lymphocytes, and multiple CD37-targeting therapies are under clinical development for NHL. However, CD37 expression is nondetectable in ∼50% of DLBCL patients, which correlates with inferior treatment outcome, but the underlying mechanisms for differential CD37 expression in DLBCL are still unknown. Here, we investigated the regulation of the CD37 gene in human DLBCL at the (epi-)genetic and transcriptional level. No differences were observed in DNA methylation within the CD37 promoter region between CD37-positive and CD37-negative primary DLBCL patient samples. On the contrary, CD37-negative DLBCL cells specifically lacked CD37 promoter activity, suggesting differential regulation of CD37 gene expression. Using an unbiased quantitative proteomic approach, we identified transcription factor IRF8 to be significantly higher expressed in nuclear extracts of CD37-positive as compared with CD37-negative DLBCL. Direct binding of IRF8 to the CD37 promoter region was confirmed by DNA pulldown assay combined with mass spectrometry and targeted chromatin immunoprecipitation (ChIP). Functional analysis indicated that IRF8 overexpression enhanced CD37 protein expression, while CRISPR/Cas9 knockout of IRF8 decreased CD37 levels in DLBCL cell lines. Immunohistochemical analysis in a large cohort of primary DLBCL (n = 206) revealed a significant correlation of IRF8 expression with detectable CD37 levels. Together, this study provides new insight into the molecular mechanisms underlying differential CD37 expression in human DLBCL and reveals IRF8 as a transcriptional regulator of CD37 in B-cell lymphoma.

Preoperative low skeletal muscle mass as a risk factor for pharyngocutaneous fistula and decreased overall survival in patients undergoing total laryngectomy.

BACKGROUND: Low skeletal muscle mass (SMM) is associated with postoperative complications, prolonged hospital stay, and short overall survival (OS) in surgical oncology. We aimed to investigate this association in patients undergoing total laryngectomy (TL). METHODS: A retrospective study was performed of patients undergoing TL. SMM was measured using CT or MRI scans at the level of the third cervical vertebra (C3). RESULTS: In all, 235 patients were included. Low SMM was observed in 109 patients (46.4%). Patients with low SMM had more pharyngocutaneous fistulas (PCFs) than patients with normal SMM (34.9% vs 20.6%; P = .02) and prolonged hospital stay (median, 17 vs 14 days; P < .001). In multivariate analysis, low SMM (hazards ratio, 1.849; 95% confidence interval, 1.202-2.843) and high N stage were significant prognosticators of decreased OS. CONCLUSION: Low SMM is associated with PCF and prolonged hospital stay in patients undergoing TL. Low SMM is an independent prognostic factor for shorter OS.

Prospective comparative study of MRI including diffusion-weighted images versus FDG PET-CT for the detection of recurrent head and neck squamous cell carcinomas after (chemo)radiotherapy.

OBJECTIVE: This prospective study aims to test if MRI including diffusion weighted images can replace FDG PET-CT in the diagnosis of patients with suspicion of local recurrent head and neck squamous cell carcinomas after (chemo)radiation. METHODS: Seventy-five patients suspected of local recurrence underwent a MRI and a FDG PET-CT. Qualitative assessment of the images was performed. Reference standard was the results of biopsy or the absence of a recurrence during follow up. RESULTS: Seventy patients were included. Fifty percent had local recurrence. FDG PET-CT had accuracy of 71% compared to 73% for MRI. The sensitivity and specificity were 97% compared to 69% and 46% compared to 77% for FDG PET-CT and MRI respectively. CONCLUSIONS: MRI showed similar diagnostic accuracy, superior specificity but inferior sensitivity compared to FDG PET-CT. Based on current results, we consider MRI including diffusion weighted sequences unable to replace FDG PET-CT as a single imaging modality when local recurrent disease of HNSCC after (C)RT is suspected.

Clinical value of (dedicated) 3 Tesla and 7 Tesla MRI for cT1 glottic carcinoma: A feasibility study.

OBJECTIVE: To assess the feasibility of the clinical use of 3 Tesla and 7 Tesla Magnetic Resonance Imaging for early (cT1) glottic carcinoma, including structural assessment of technical image quality and visibility of the tumor; and if feasible, to correlate MRI findings to routine diagnostics. METHODS: Prospective feasibility study. Twenty patients with primary clinical T1 glottic carcinoma underwent both routine clinical staging and CT. In addition, a 3 T and 7 T MRI protocol, developed for small laryngeal lesions, was performed in a 4-point immobilization mask, using dedicated surface coils. Afterwards, routine endoscopic direct suspension laryngoscopy under general anaesthesia was performed. RESULTS: Only 2 of 7 (29%) of 7 T MRI scans were rated as moderate to good technical image quality. After exclusion of three patients with only mild to moderate dysplasia at the time of MRI, 13 of 17 (76%) of 3 T MRIs were of adequate technical image quality. Tumor visualization was adequate in 8 of 13 (62%) of patients with invasive squamous cell carcinomas. With exclusion of the four MRIs with motion artefacts, the tumor and its boundaries could be adequately seen in 8 of 9 (89%) patients with squamous cell carcinoma versus only one in four (25%) of patients with carcinoma in situ lesions. CONCLUSIONS: 7 Tesla MRI was considered not feasible. 3 Tesla MRI, with adequate patient selection, namely clinical exclusion of patients with a history of claustrophobia and inclusion of only histologically proven invasive squamous cell carcinoma, can be feasible. Especially with further improvement of MR image quality. LEVEL OF EVIDENCE: 2B, prospective diagnostic study.

Depth of invasion in patients with early stage oral cancer staged by sentinel node biopsy.

BACKGROUND: To investigate if depth of invasion (DOI) can predict occult nodal disease in patients with cT1-2N0 (7th TNM) oral squamous cell carcinoma (OSCC) staged by sentinel lymph node biopsy (SLNB). METHODS: In 199 OSCC patients, DOI measurements and SLNB were performed. RESULTS: Metastases were found in 64 of 199 patients (32%). Of these 64 patients, the mean DOI was 6.6 mm compared to 4.7 mm in patients without metastases (P = .003). The ROC-curve showed an area under the curve of 0.65 with a most optimal cutoff point of 3.4 mm DOI (sensitivity 83% and specificity 47%). Regional metastases were found in 15% of patients with DOI ≤ 3.4 mm. CONCLUSION: DOI seems to be a poor predictor for regional metastasis in patients with cT1-2N0 OSCC. Therefore, staging of the neck using SLNB in patients with early stage oral cancer should also be performed in tumors with limited DOI and probably in T3 (8th TNM) OSCC ≤4 cm diameter.

Dilation after laryngectomy: Incidence, risk factors and complications.

BACKGROUND: Neopharyngeal stenosis is a recognized sequela of total laryngectomy (TL). We aim to investigate the incidence of stenosis requiring dilation, risk factors for stenosis and complications of dilation. METHODS: Retrospective cohort study of patients undergoing TL in two dedicated head and neck centers in the Netherlands. RESULTS: A total of 477 patients, (81% men, median age of 64 at TL) were included. Indication for TL was previously untreated primary tumor in 41%, salvage following (chemo)radiotherapy (CRT) in 44%, dysfunctional larynx in 9% and a second primary tumor in 6%. The cumulative incidence of dilatation at 5 years was 22.8%, and in total 968 dilatations were performed. Median number of dilations per patient was 3 (range 1-113). Female gender, a hypopharynx tumor, and (C)RT before or after the TL were significantly associated with stenosis requiring dilation. We observed 8 major complications (0.8%) predominantly during the first dilation procedures. Use of general anesthesia is a risk factor for complications. The most frequent major complication was severe esophageal perforation (n = 6 in 5 patients). CONCLUSION: The cumulative incidence of pharyngeal stenosis needing dilation was 22.8% at 5 years. Roughly half of these patients could be treated with a limited number of dilations, the rest however needed ongoing dilations. Major complications are rare (0.8%) but can be life threatening. General anesthetics is a risk factor for complications, and complications occurred predominantly during the first few dilations procedures. This should alert the physician to be extra careful in new patients.

Systematic review of the diagnostic value of magnetic resonance imaging for early glottic carcinoma.

Objective: In early glottic cancer, accurate assessment of tumor extension, including depth infiltration, is of great importance for both staging, therapeutic approach and systematic comparison of data. Our goal was to assess the diagnostic value of MRI in pre-therapeutic staging of primary early stage (T1 and T2) glottic carcinoma. Study design: Systematic review of literature. Methods: We conducted a systematic search in Pubmed, Embase, and Scopus up to September 23, 2016. Included studies were selected and critically appraised for relevance and validity. Results: Seven out of 938 unique articles were selected, including 64 cases. MRI over-staged 6% and under-staged 13% of cT1 and cT2 tumors. However, available data is heterogeneous, very limited and mainly based on subanalysis of a small amount of patients. Reported MRI protocols appear to be suboptimal for small laryngeal lesions. Diagnostic value of MRI for subtle depth infiltration or laryngeal anatomical subsites (eg, laryngeal ventricle, vocal cord, etc.) could not be assessed. Conclusions: More studies are needed to assess the diagnostic value of MRI for small glottic tumors.

Influence of tumor and microenvironment characteristics on diffusion-weighted imaging in oropharyngeal carcinoma: A pilot study.

OBJECTIVES: Diffusion weighted imaging (DWI) is a frequently performed MRI sequence in cancer patients. While previous studies have shown the clinical value of the apparent diffusion coefficient (ADC) for response prediction and response monitoring, less is known about the biological background of ADC. In the tumor microenvironment, hypoxia and increased proliferation of tumor cells contribute to resistance to (radio-)therapy, while high T-cell influx is related to better prognosis. We investigated the correlation between these three tissue characteristics and ADC in 20 oropharyngeal squamous cell carcinoma patients. MATERIALS AND METHODS: 20 patients with oropharyngeal squamous cell carcinoma (OPSCC) who underwent 1.5 T MRI, including DWI were included in this pilot study. Corresponding formalin-fixed paraffin-embedded tumor tissues were immunohistochemically analyzed for protein expression of hypoxia-inducible factor 1a (HIF-1a), Ki-67 and CD3. Expression of these markers was correlated with ADC. RESULTS: ADC negatively correlated with Ki-67 expression (p = .024) in tumor cells. There was a significant negative correlation between ADC and CD3-positive cell count (p = .009). No correlation was observed between HIF-1a expression and ADC. CONCLUSION: This study suggests that ADC reflects characteristics of tumor cells as well as the surrounding microenvironment. Interestingly, high tumor proliferation (a negative prognostic factor) and high T-cell influx (a beneficial prognostic factor) are both associated with a lower ADC. Further studies should be performed to correlate ADC to these histological characteristics in relation to previously known factors that affect ADC, to gain further knowledge on the role of DW-MRI in diagnostics and personalized medicine.

The interobserver agreement in the detection of recurrent HNSCC using MRI including diffusion weighted MRI.

INTRODUCTION: For the detection of local recurrences of head and neck squamous cell carcinomas (HNSCC) after (chemo)radiation, diagnostic imaging is generally performed. Diffusion weighted magnetic resonance imaging (DW-MRI) has been proven to be able to adequately diagnose the presence of cancer. However evaluation of DW-MR images for recurrences is difficult and could be subject to individual interpretation. AIM: To determine the interobserver agreement, intraobserver agreement and influence of experience of radiologists in the assessment of DW-MRI in patients clinically suspected of local recurrent HNSCC after (chemo)radiation. METHODS: Ten experienced head and neck radiologists assessed follow-up MRI including DW-MRI series of 10 patients for the existence of local recurrence on a two point decision scale (local recurrence or local control). Patients were clinically suspected for a recurrence of laryngeal (n = 3), hypopharyngeal (n = 3) or oropharyngeal (n = 4) cancer after (chemo)radiation with curative intent. Fleiss' and Cohen's Kappa were used to determine interobserver agreement and intraobserver agreement, respectively. RESULTS: Interobserver agreement was κ = 0.55. Intraobserver agreement was κ = 0.80. Prior experience within the field of radiology and with DW-MRI had no significant influence on the scoring. CONCLUSION: For the assessment of HNSCC recurrence after (chemo)radiation by DW-MRI, moderate interobserver agreement and substantial intraobserver agreement was found.

Recurrent laryngeal nerve injury after esophagectomy for esophageal cancer: incidence, management, and impact on short- and long-term outcomes.

BACKGROUND: Recurrent laryngeal nerve (RLN) injury caused by esophagectomy may lead to postoperative morbidity, however data on long-term recovery are scarce. The aim of this study was to evaluate the consequences of RLN palsy (RLNP) in terms of pulmonary morbidity and long-term functional recovery. METHODS: Patients who underwent a 3-stage transthoracic (McKeown) or a transhiatal esophagectomy for esophageal carcinoma in the University Medical Center Utrecht (UMCU) between January 2004 and March 2016 were included from a prospective database. Multivariable analyses were conducted to assess the association between RLNP and pulmonary complications and hospital stay. Data regarding long-term recovery were summarized using descriptive statistics. RESULTS: Out of the 451 included patients, 47 (10%) were diagnosed with RLNP. Of the patients with RLNP, 34 (7%) had a unilateral lesion, 8 (2%) had a bilateral lesion, and in 5 (1%) the location of the lesion was unknown. The incidence of RLNP was 3/127 (2%) in the transhiatal group, and 44/324 (14%) in the McKeown group. RLNP after McKeown esophagectomy was associated with a higher incidence of pulmonary complications (OR 2.391; 95% CI 1.222-4.679; P=0.011), as well as a longer hospital stay (+4 days) (P=0.001). Of the RLNP patients with more than 6 months follow up almost half recovered fully {median follow-up of 17.5 [7-135] months}. Of the remainder, six required a surgical intervention and the others had residual symptoms. CONCLUSIONS: RLNP after McKeown esophagectomy is associated with an increased pulmonary complication rate, longer hospital stay, and a moderate long-term recovery. Further studies are necessary that examine technologies, which may reduce RLNP incidence and contribute to the early detection and treatment of RLNP.

Short-duration enzymatic treatment promotes integration of a cartilage graft in a defect.

OBJECTIVES: Surgical manipulation of cartilage tissue is associated with chondrocyte death in the wound edges that hinders integration. The objective of this study was to evaluate the effect of a short course of treatment of a cartilage graft with a combination of hyaluronidase and collagenase on chondrocyte density and integrative capacity. METHODS: Cartilage explants were treated with enzymes for various time periods and at various concentrations. A central core was punched out of a larger explant, treated with enzymes, reimplanted, and placed subcutaneously in athymic mice. The number of chondrocytes in the wound edges was counted, and the integrative capacity of the grafts was evaluated by histology. RESULTS: Treatment with collagenase for 48 hours led to a significant increase in the number of vital chondrocytes and restored it to normal after 14 days of culture. Treatment with hyaluronidase and collagenase for 48 hours further increased chondrocyte densities to supranormal values. Shortening the treatment to 1 hour restored the chondrocyte density to normal after 14 days of culture. In vivo integration experiments showed increased chondrocyte densities in treated wound edges and extracellular matrix fibers crossing over from enzyme-treated parts to untreated parts. CONCLUSIONS: Short-duration treatment of a cartilage graft with a combination of hyaluronidase and collagenase increases cell density at wound edges and promotes integrative repair.