Intraoperative Samples Research Articles

Intraoperative Cytologic Sampling for Resected Pancreatic and Periampullary Adenocarcinoma with Implications for Locoregional Recurrence-Free Survival.

We hypothesized that pancreatic and periampullary adenocarcinoma recurrence after surgical resection may be affected by the shedding of malignant epithelial cells during surgical dissection and that this may have implications for disease recurrence and survival. In this ongoing, investigator-initiated prospective randomized controlled trial, patients with pancreatic and periampullary adenocarcinoma were randomized intraoperatively, postresection into 3 study arms: peritoneal lavage using 10 L normal saline or distilled water, or control group with no lavage. Peritoneal fluid was sampled for cytologic analysis (cytospin, cellblock, immunohistochemistry-Ber-EP4 antibody) at 4 stages: (1) abdominal entry pre-dissection, (2) resection bed after tumor extirpation, (3) ex vivo resected specimen, and (4) resection bed postlavage. Between April 2016 and May 2018, 193 patients who underwent randomization for the study also underwent the described cytologic sampling. Of these, 167 patients (86.5%) were ultimately found to have pancreatic or periampullary adenocarcinoma. Before dissection (1) on cytospin analysis, 4.9% were positive, which rose to 10.2% intraoperatively (2), 16.7% ex vivo (3), and decreased to 4.3% (4) after lavage. Lymph node metastasis, margin involvement, and perineural invasion did not correlate with locoregional recurrence (LR). Tumor cells in the ex vivo cytospin (3) correlated with LR (odds ratio 3.8 [95% CI 1.6 to 9.2], p = 0.005) and LR disease-free survival (p = 0.007). Cox regression analysis revealed ex vivo cytospin positivity to be strongly associated with poorer LR disease-free survival (hazard ratio 2.26 [95% CI 1.16 to 4.42], p = 0.017). Cytologic sampling from ex vivo specimen irrigation after surgical resection of pancreatic and periampullary adenocarcinoma may have implications for LR, survival, and treatment, suggesting a possible cancer cell shedding phenotype.

Changes in the type and amount of bone collagens in chronic suppurative otitis media

Comparative assessment of the collagen-tissue interaction in the bone tissue of the middle ear structures in patients with chronic suppurative otitis media (CSOM). A prospective study of 42 patients aged 16-60 years with CSOM admitted for reconstructive sanitizing surgery was performed. To study the collagen-tissue interaction, intraoperative samples of the bone tissue of the middle ear were used. A software calculation of vascular-stromal areas and ratios of various types of bone tissue collagen was carried out during histomorphological examination. The quantitative and qualitative parameters of bone tissue collagen obtained intraoperatively in patients with CSOM were studied. The cavities of the middle ear are in the phase of a chronic purulent process, when the bone structures are morphologically disorganized according to the pathological type, and sclerosis with overgrowth of the cellular structure of the mastoid process is considered a favorable outcome for delimiting the focus of inflammation in the pyramid of the temporal bone. Changes in the processes of collagen remodeling of bone structures contribute to the maintenance of inflammation of the middle ear in all clinical forms of CSOM. Pathological osteogenesis can serve as an indicator of the progressive course of a purulent-destructive process in the cavities of the middle ear, which makes it possible to reliably determine the rate of bone tissue transformation to predict relapse after reconstructive and sanitizing surgery.

“Answers in hours”: A prospective clinical study using nanopore sequencing for bile duct cultures

BackgroundSurgical site infection is a major source of morbidity in patients undergoing pancreatic head resection and is often from organisms in intraoperative bile duct cultures. As such, many institutions use prolonged prophylactic antibiotics and tailor based on bile duct cultures. However, standard cultures take days, leaving many patients unnecessarily on prolonged antibiotics. Nanopore sequencing can provide data in hours and, thus, has the potential to improve antibiotic stewardship. The present study investigates the feasibility of nanopore sequencing in intraoperative bile samples. MethodsPatients undergoing pancreatic head resection were included. Intra-operative bile microbial profiles were determined with standard cultures and nanopore sequencing. Antibiotic recommendations were generated, and time-to-results determined for both methods. Organism yields, resistance patterns, antibiotic recommendations, and costs were compared. ResultsOut of 42 patients, 22 (52%) had samples resulting in positive standard cultures. All positive standard cultures had microbes detected using nanopore sequencing. All 20 patients with negative standard cultures had negative nanopore sequencing. Nanopore sequencing detected more bacterial species compared to standard cultures (10.5 vs 4.4, p < 0.05) and more resistance genotypes (10.3 vs 2.7, p < 0.05). Antimicrobial recommendations based on nanopore sequencing provided coverage for standard cultures in 27 out of 44 (61%) samples, with broader coverage recommended by nanopore sequencing in 13 out of 27 (48%) of these samples. Nanopore sequencing results were faster (8 vs 98 hours) than standard cultures but had higher associated costs ($165 vs $38.49). ConclusionRapid microbial profiling with nanopore sequencing is feasible with broader organism and resistance profiling compared to standard cultures. Nanopore sequencing has perfect negative predictive value and can potentially improve antibiotic stewardship; thus, a randomized control trial is under development.

Scintigraphic Imaging of Inflammation in the Aortic Wall Using 99mTc-Pyrophosphate.

The aim of this study was to develop and test a technique for scintigraphic examination of the thoracic aorta, which allows for visualizing foci of inflammation.Materials and MethodsThe study included 15 patients (median age — 61 [47; 73] years) with aortic dilatation more than 45 mm and thoracic aortic aneurysm who were candidates for surgical treatment. All patients underwent a chest scintigraphy with 99mTc-pyrophosphate 48 h before surgery to identify foci of inflammation in the aortic wall. The new technique included intravenous administration of 370 MBq of a radiopharmaceutical (RP), registration of scintigrams at 3 and 6 h after injection of RP in a tomographic mode combined with X-ray computed tomography. After the image reconstruction, subtraction of the later scintigrams from the early ones was performed, followed by analysis of the final images. The results of scintigraphy were compared with the histological data obtained from intraoperative samples of resected aorta.ResultsAccording to the results of this novel scintigraphic technique, artifacts from the radioactivity of the vascular blood pool were eliminated and pathological RP uptake was identified in 5 (33.3±1.5%) out of 15 examined patients. The “focus/vessel lumen” ratio averaged at 1.47 [1.30; 1.48]. Histological examination of resected aorta samples confirmed the presence of chronic inflammation in 4 (26.7±1.3%) out of 15 patients. Parameters of diagnostic efficiency were: sensitivity — 100%, specificity — 91%, diagnostic accuracy — 93%.ConclusionThe method of scintigraphic diagnostics of inflammatory processes in the aorta using 99mTc-pyrophosphate, supplemented by subtraction of the late from the early images, makes it possible to eliminate artifacts from the radioactivity of the aortic blood pool and to reveal the pathological RP accumulation indicating the areas of inflammation in the aortic wall.

The benefits of systematic intraoperative sampling during lower limb arthroplasties due to sequelae from prior osteoarticular infections: A retrospective study of 92 cases

IntroductionOsteoarticular infections (OAIs) of native joints lead to cartilage damage which may require subsequent arthroplasty. There is no consensus on systematic intraoperative microbiological sampling when performing an arthroplasty on a native joint with a history of OAI. We carried out a retrospective study to: (1) identify the frequency of the persistence of the microorganism(s) involved during the initial, presumed cured OAI, when performing an arthroplasty for sequelae of osteoarthritis, (2) to find an association between the length of time between the OAI and arthroplasty, and the recurrence of bacterial infection, (3) to assess the influence of the presence of hardware on the risk of infectious recurrence. HypothesisSystematic sampling is justified during a subsequent arthroplasty after an OAI, even after a prolonged period. Material and methodThis single-center, retrospective descriptive study included all patients whose indication for arthroplasty resulted from osteoarthritis, osteitis or bacterial osteomyelitis of a native joint, or in the aftermath of an infection post osteosynthesis. All patients were considered to have recovered from the initial infection at the time of the arthroplasty. Between 2008 and 2019, 92 patients were included in the study, with an average age of 56.5years (range: 21–97years). OAI occurred at a mean age of 35years (range: 1–84years). The average time from OAI to implantation was 15years (range: 1–65years). The bacteria most frequently found in the initial OAI was Staphylococcus aureus, involved in 35.8% of cases (n=33/92). ResultsThe intraoperative samples came back positive in 17% of cases (n=16/92), including 9 positive for the same bacteria as the OAI (56%, n=9/16). For these 16 cases, the time between the OAI and the arthroplasty was 1year for 5 patients, between 1 and 15years for 5 patients and greater than 15years for 6 patients. For 3 positive patients, the information on the initial microorganism was not known and 4 patients were positive for a bacterium different from the initial one. The time from the initial OAI to the arthroplasty was not associated with positive results (p=0.38). There was no significant difference between a positive culture at the time of arthroplasty and the initial type of OAI [native joint versus presence of hardware and/or open fracture (p=0.41)]. ConclusionThe results of this work suggest there is value in microbiological sampling when performing an arthroplasty on a previously infected joint, regardless of the duration of the infection. Level of evidenceIV; retrospective study.

O-P01 Potential Utility of Intraoperative Fluid Amylase Measurement During Pancreaticoduodenectomy

Abstract Background Postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD) is a source of major morbidity and mortality. Early diagnosis and treatment of POPF is mandatory to improve patient outcomes, and clinical risk scores may be combined with postoperative drain fluid amylase (DFA) values to stratify patients. The aim of this study was to determine if intraoperative fluid amylase values (IFA) correlate with DFA1 and POPF. Methods In consecutive patients undergoing PD between February and November 2020, intraoperative samples of intra-abdominal fluid adjacent to the pancreatic anastomosis were taken and sent for fluid amylase measurement prior to abdominal closure. Data regarding patient demographics, postoperative DFA values, complications and mortality were prospectively collected. Results Patient Demographics: Data was obtained for 52 patients with a median alternative Fistula Risk Score (aFRS) of 9.4. Postoperative complications occurred in 20 patients (38%), including five Clavien grade 3+. There were eight POPFs and two patients died (pneumonia/sepsis). There was significant correlation between IFA and DFA1 (Pearson’s correlation: R2=0.713; p &amp;lt; 0.001) and DFA3 (p &amp;lt; 0.001), and median IFA was higher in patients with POPF than patients without (1232.5 vs. 122; p = 0.0003). IFA&amp;gt;260 U/l predicted POPF with sensitivity, specificity, PPV and NPV of 88%, 75%, 39% and 97%, respectively. The incidence of POPF was 43% in high risk (high aFRS/IFA) and 0% in low risk patients (low aFRS/IFA). Complications: Conclusions Intraoperative fluid amylase closely correlated with postoperative pancreatic fistula, and may be a useful adjunct to clinical risk scores to stratify patients during pancreatico-duodenectomy, allowing targeted intervention to reduce the clinical impact of pancreatic fistula.It is possible to detect fluid amylase adjacent to the completed pancreatic anastomosis in patients undergoing PD. Presence of IFA correlates with postoperative DFA and POPF. IFA increases the accuracy of the alternate Fistula Risk Score in predicting POPF. Low risk patients with a low IFA may be suitable for a ‘no drain’ strategy, whilst patients with a high IFA may benefit from intraoperative mitigation strategies to reduce the incidence and/or severity of a postoperative pancreatic fistula.

Mycotic Pseudoaneurysm of Carotid Artery as a Rare Complication of Lemierre Syndrome

Mycotic Pseudoaneurysm of Carotid Artery as a Rare Complication of Lemierre Syndrome

Pneumococcal prosthetic joint infection – A challenging diagnosis

• Streptococcus pneumoniae may cause haematogenous infection of prosthetic joints. • Previous antibiotics may result in negative investigations and diagnostic dilemmas. • Intra-operative samples should be sent for 16S PCR when tissue samples are culture negative. • A two-stage surgical revision combined with six weeks of antibiotics can be curative. • Prosthetic joint infection can be a mentally and physically challenging diagnosis for the patient. Prosthetic joint infection (PJI) is a relatively rare (~1%) but catastrophic complication of joint arthroplasty. It is commonly caused by Staphylococcus aureus . Streptococcus pneumoniae is mostly associated with respiratory tract infections, sinusitis and meningitis, but is occasionally involved in native joint septic arthritis in a small percentage of cases. Its role and pathogenicity in PJI is largely unknown currently. We report a case of hematogenous infection of a total knee replacement by Streptococcus pneumoniae from a concurrent chest infection. Culture and 16S PCR of a pre-operative joint aspirate and white cell CT SPECT were negative for the index patient, posing significant diagnostic challenges. The definitive diagnosis was only achieved from intraoperative sampling during emergency debridement prior to which antibiotic treatment had been interrupted. The patient was eventually cured after a two-stage revision of the prosthetic joint, combined with a 6-week course of intravenous ceftriaxone.

Early assessment of circulating tumor DNA after curative-intent resection predicts tumor recurrence in early-stage and locally advanced non-small-cell lung cancer.

Circulating tumor DNA (ctDNA) has demonstrated great potential as a noninvasive biomarker to assess minimal residual disease (MRD) and profile tumor genotypes in patients with non‐small‐cell lung cancer (NSCLC). However, little is known about its dynamics during and after tumor resection, or its potential for predicting clinical outcomes. Here, we applied a targeted‐capture high‐throughput sequencing approach to profile ctDNA at various disease milestones and assessed its predictive value in patients with early‐stage and locally advanced NSCLC. We prospectively enrolled 33 consecutive patients with stage IA to IIIB NSCLC undergoing curative‐intent tumor resection (median follow‐up: 26.2 months). From 21 patients, we serially collected 96 plasma samples before surgery, during surgery, 1–2 weeks postsurgery, and during follow‐up. Deep next‐generation sequencing using unique molecular identifiers was performed to identify and quantify tumor‐specific mutations in ctDNA. Twelve patients (57%) had detectable mutations in ctDNA before tumor resection. Both ctDNA detection rates and ctDNA concentrations were significantly higher in plasma obtained during surgery compared with presurgical specimens (57% versus 19% ctDNA detection rate, and 12.47 versus 6.64 ng·mL−1, respectively). Four patients (19%) remained ctDNA‐positive at 1–2 weeks after surgery, with all of them (100%) experiencing disease progression at later time points. In contrast, only 4 out of 12 ctDNA‐negative patients (33%) after surgery experienced relapse during follow‐up. Positive ctDNA in early postoperative plasma samples was associated with shorter progression‐free survival (P = 0.013) and overall survival (P = 0.004). Our findings suggest that, in early‐stage and locally advanced NSCLC, intraoperative plasma sampling results in high ctDNA detection rates and that ctDNA positivity early after resection identifies patients at risk for relapse.

Challenges in the Microbiological Diagnosis of Implant-Associated Infections: A Summary of the Current Knowledge.

Implant-associated infections are characterized by microbial biofilm formation on implant surface, which renders the microbiological diagnosis challenging and requires, in the majority of cases, a complete device removal along with a prolonged antimicrobial therapy. Traditional cultures have shown unsatisfactory sensitivity and a significant advance in the field has been represented by both the application of the sonication technique for the detachment of live bacteria from biofilm and the implementation of metabolic and molecular assays. However, despite the recent progresses in the microbiological diagnosis have considerably reduced the rate of culture-negative infections, still their reported incidence is not negligible. Overall, several culture- and non-culture based methods have been developed for diagnosis optimization, which mostly relies on pre-operative and intra-operative (i.e., removed implants and surrounding tissues) samples. This review outlines the principal culture- and non-culture based methods for the diagnosis of the causative agents of implant-associated infections and gives an overview on their application in the clinical practice. Furthermore, advantages and disadvantages of each method are described.

Adequacy of Mediastinal Lymph Node Sampling in Patients With Lung Cancer Undergoing Lung Resection

Intraoperative mediastinal lymph node sampling (MLNS) is a crucial component of lung cancer surgery. Whilst several sampling strategies have been clearly defined in guidelines from international organizations, reports of adherence to these guidelines are lacking. We aimed to assess our center's adherence to guidelines and determine whether adequacy of sampling is associated with survival. A single-center retrospective review of consecutive patients undergoing lung resection for primary lung cancer between January 2013 and December 2018 was undertaken. Sampling adequacy was assessed against standards outlined in the International Association for the Study of Lung Cancer 2009 guidelines. Multivariable logistic and Cox proportional hazards regression analyses were used to assess the impact of specific variables on adequacy and of specific variables on overall survival, respectively. A total of 2380 patients were included in the study. Overall adequacy was 72.1% (n= 1717). Adherence improved from 44.8% in 2013 to 85.0% in 2018 (P< 0.001). Undergoing a right-sided resection increased the odds of adequate MLNS on multivariable logistic regression (odds ratio 1.666, 95% confidence interval [CI]: 1.385-2.003, P< 0.001). Inadequate MLNS was not significantly associated with reduced overall survival on log rank analysis (P= 0.340) or after adjustment with multivariable Cox proportional hazards (hazard ratio 0.839, 95% CI 0.643-1.093). Adherence to standards improved significantly over time and was significantly higher for right-sided resections. We found no evidence of an association between adequate MLNS and overall survival in this cohort. A pressing need remains for the introduction of national guidelines defining acceptable performance.

Cutibacterium acnes clonal complexes display various growth rates in blood culture vials used for diagnosing orthopedic device-related infections

ObjectivesBlood culture bottles (BCBs) are commonly used for the diagnosis of infections associated with orthopedic devices. Although Cutibacterium acnes is an important pathogen in orthopedics, relatively little is known about its growth characteristics in BCBs. This prompted us to analyze the influence of bacterial genotype and clinical significance on time-to-detection (TTD) in BCBs. MethodsWe reviewed 59 cases of orthopedic device-related infections in which at least one intraoperative specimen yielded a pure C. acnes culture from anaerobic BCBs (BD Bactec Lytic/10 Anaerobic/F; Lytic-Ana) and/or solid media. A strain was considered infectant if the same genotype was present in two or more intraoperative samples. From these cases, we isolated a total of 72 unique C. acnes strains belonging to four multilocus sequence type clonal complexes (CCs): CC18, CC28, CC36 and CC53. Growth rate and TTD in Lytic-Ana BCB were studied under experimental conditions (inoculation of standard inoculum) and in clinical samples (inoculation of periprosthetic tissue samples). ResultsMedian TTD values were shorter for CC53 compared to other CCs under experimental conditions (69 vs. 103 h; p < 0.001) and from clinical specimens (70 vs. 200 h; p = 0.02). Infectant strains had a shorter median TTD compared to contaminant strains in a clinical situation, while the difference was not observed under experimental conditions. ConclusionsThe detection dynamics of C. acnes in Lytic-Ana BCBs were associated with genotype. Thus, TTD not only reflects the bacterial load in clinical samples, but may also reflect the intrinsic properties of the clonal complex of C. acnes.

A Randomized Controlled Trial with Intraoperative Cytologic Sampling for Resected Periampullary Adenocarcinoma with Implications for Locoregional Recurrence-Free Survival

A Randomized Controlled Trial with Intraoperative Cytologic Sampling for Resected Periampullary Adenocarcinoma with Implications for Locoregional Recurrence-Free Survival

Metabolic and functional imaging employment in the differentiation of brown tumors from bone metastases in a case of primary papillary thyroid cancer and parathyroid adenoma: case report

BackgroundBrown tumors are benign osteoclastic bone lesions encountered in patients with hyperparathyroidism. These tumors may demonstrate aggressive, destructive features in the skeleton and imitate metastatic bone lesions, particularly in patients with known primary neoplasm. In this case report of recurrent papillary thyroid cancer and ectopic parathyroid adenoma, we shed light on the importance of combining different nuclear medicine imaging modalities to differentiate brown tumors from metastatic bone lesions.Case presentationWe present a 39-year-old woman with a known history of papillary thyroid carcinoma classic type stage pT1N1b post-total thyroidectomy and radioactive iodine (I-131) therapy (RAI) presented with upper limb weakness and pain. An expansile lytic lesion involving the 6th cervical vertebra was seen in cervical spine MRI, which was suspicious for metastatic deposit. Therapeutic and diagnostic I-131 whole-body scans were negative for any I-13-avid lesions. Laboratory results revealed high calcium, parathyroid hormone, and alkaline phosphatase. A Technetium-99m-sestamibi (Tc-99m MIBI) scan was done with the standard protocol of spot views to the neck and upper chest area to localize any suspicious parathyroid adenoma. The scan demonstrated right supraclavicular and mediastinal Tc-99m MIBI-avid lesions suspicious for being ectopic parathyroid adenomas. Whole-body fluorine-18-2-fluoro-2-deoxy-d-glucose (18F-FDG), positron emission tomography/computed tomography (PET/CT) (18F-FDG PET/CT) was performed for further evaluation. It demonstrated multiple focal lytic skeletal lesions of abnormal increased FDG uptake as well as right supraclavicular FDG-avid lymph nodes. However, the superior mediastinal lesion was non-FDG-avid, suggesting the existence of two different entities: ectopic parathyroid adenoma with multiple brown tumors and metastatic right supraclavicular lymph nodes. The patient underwent right neck dissection and superior mediastinal mass excision. An intra-operative fresh serum parathyroid sample was sent, which dropped down to 100ng/ml from 863.7ng/ml. Later, histopathological results revealed that the right supraclavicular lymph nodes were metastatic papillary thyroid carcinoma. At the same time, the superior mediastinal mass proved to be parathyroid adenoma by histopathology, confirming the 18F-FDG PET/CT findings.ConclusionsIn the case of papillary thyroid carcinoma, metastatic lymph nodes with hyperparathyroidism, and evidence of lytic bone lesions, careful interpretation of the different metabolic and functional imaging modalities are needed to exclude the concurrent parathyroid adenoma and facilitate the differentiation of brown tumors from bone metastases, leading to appropriate surgical and medical treatment plans.

413 The Clinical Efficacy of Intra-Operative Peritoneal Fluid Sampling in Abdominal infections

Abstract Aim To uncover the practical efficacy of intra-operative peritoneal fluid sampling and the impact on antibiotic prescription and clinical outcomes in patients undergoing emergency surgery due to intra-abdominal infections. Method Our retrospective study included all patients undergoing emergency surgery for intra-abdominal infections at Southend University Hospital over 6 months (January – July 2019). Data was collected from electronic patient records, case notes and microbiology reports and included the following information: patient age demographics; type of infection; peritoneal fluid sampling indication; samples taken; details of swab culture report including organisms grown and antibiotic sensitivity; clinical course and incidence of subsequent intra-abdominal infection to include readmission and/or further procedures; the type, duration and route of antibiotic prescribed and duration of hospital stay. This audit was approved by the Departmental Audit Lead. Results 441 patients undergoing emergency surgery for intra-abdominal infection were identified. After exclusions, intra-operative peritoneal fluid samples were indicated in 77 patients (mean age 39.4 years). Of these only 3 had samples taken (3.9%). The most common organisms isolated were mixed anaerobes followed by Streptococcus angiosus. The most common antibiotic sensitivity was Metronidazole and Penicillin. One readmission occurred due to an intra-abdominal tubo-ovarian abscess. Conclusions The study shows that the current practice in our hospital regarding intra-operative peritoneal fluid sampling in intra-abdominal infections reflects the present widely held attitudes regarding its reduced practical utility. Abandoning routine sampling had no significant impact on the clinical course and may be more cost-effective. The study may help surgeons reflect on changing perspectives on this traditional practice.

The alpha defensin lateral flow test is effective in predicting eradication of periprosthetic joint infection after surgical debridement

The primary aim of this study was to assess the utility of the alpha defensin lateral flow (ADLF) test for predicting the eradication of PJI after surgical debridement. The secondary aim was to describe the reliability of ADLF test in diagnosis of PJI intra- operatively. A prospective observational study was conducted in three independent orthopaedic centres. Twenty-two patients undergoing revision surgery (debridement, antibiotics and implant retention (DAIR), single or two-stage revision) for PJI were recruited, 13 female and 9 male with an average age of 64 years. Samples were collected intra-operatively at the start of the first surgical procedure and then at the completion of debridement or prior to reimplantation depending on the operation performed. These samples were tested using ADLF and then sent for microbiological analysis. The ADLF result was then compared to the corresponding culture result in order to determine the diagnostic predictive accuracy. The reliability of ADLF test to predict eradication of infection after debridement of PJI was excellent for specificity and positive predictive value (PPV) of which both where 100%, but had a poor sensitivity (14.3%) and negative predictive value (NPV) (62.5%). The reliability of ADLF test to predict PJI was poor with only a 50% sensitivity and specificity. The ADLF test has a high specificity and PPV for diagnosing eradication of infection after debridement. In contrast the ADLF testing appears to have poor diagnostic accuracy for PJI when used on intra-operative samples, prior to surgical intervention.

Is intraoperative margin sampling necessary in inverted papilloma resection?

To explore the association between intraoperative surgical margin sampling by the frozen sections and recurrence in inverted papilloma surgery. A multicenter, retrospective study of patients who underwent attachment-oriented IP resection in four tertiary care medical centers with a minimal follow-up of 36months. The study included 220 surgeries with a mean follow-up period of 49months (range 36-204). The endoscopic approach was used in all but 4 cases; 73% of procedures were primary. Overall recurrence was 10.45% (n = 23). Squamous cell carcinoma was found in 5 cases (2.2%). Intraoperative margin sampling was obtained in 145 cases. There was no difference in the recurrence rate between frozen section and no-frozen section groups (p = 0.44). Furthermore, margin sampling in various sites of tumor origin, in cases with concomitant nasal polyps (p = 0.53) and in revision cases (p = 0.08) showed no correlation with recurrence. In 26 cases when the surgery was extended following a positive frozen section, there was a significantly higher recurrence rate (OR = 6.94). According to our results, intraoperative margin sampling did not affect the recurrence rate of IP, and therefore, its routine use should be questioned.

MP07-12 REVISITING THE ROLE OF OXALOBACTER FORMIGENES IN STONE FORMATION: A DEEP DIVE INTO THE MICROBIOME AT MULTIPLE BODY SITES

You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology (MP07)1 Sep 2021MP07-12 REVISITING THE ROLE OF OXALOBACTER FORMIGENES IN STONE FORMATION: A DEEP DIVE INTO THE MICROBIOME AT MULTIPLE BODY SITES Kait Al, Benjamin Joris, John Denstedt, John Chmiel, Jennifer Bjazevic, Gregory Gloor, Hassan Razvi, and Jeremy Burton Kait AlKait Al More articles by this author , Benjamin JorisBenjamin Joris More articles by this author , John DenstedtJohn Denstedt More articles by this author , John ChmielJohn Chmiel More articles by this author , Jennifer BjazevicJennifer Bjazevic More articles by this author , Gregory GloorGregory Gloor More articles by this author , Hassan RazviHassan Razvi More articles by this author , and Jeremy BurtonJeremy Burton More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001980.12AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: There is a longstanding belief that intestinal colonization by Oxalobacter formigenes can reduce the risk of oxalate-based stone disease through its capacity to degrade calcium oxalate. However, literature on the topic remains controversial, and mounting evidence instead suggests a polymicrobial effect from both the urinary and gut microbiome may play a greater role in the disease. The aim of the present study was to address this knowledge gap by comprehensively characterizing the microbial communities of interest in kidney stone formers and healthy controls. METHODS: In the largest study of its kind, the microbiota of fecal and urine samples from 83 stone formers (SF) and 30 healthy controls (HC) was evaluated with whole shotgun metagenomic sequencing and 16S rRNA amplicon sequencing, respectively. Stone fragments and intraoperative urine from SF were also analyzed, and urinary oxalate concentrations were determined with HPLC. RESULTS: The findings demonstrate that despite similar dietary micronutrient consumption between the groups, urinary oxalate concentrations were higher in the SF cohort. Alongside these differences, the SF gut microbiota was significantly enriched in Enterobacteriaceae and several presumptive uropathogens, while depleted in microbes known to be beneficial such as Faecalibacterium prausnitzii. The gut microbiota of SFs was also aberrant compared to HC in several metabolic capacities. Importantly, there was no difference between groups in the relative abundance of O. formigenes, nor genes involved in oxalate catabolism including formyl-CoA transferase and oxalyl-CoA decarboxylase. The urinary microbiota was altered between HC and SF, and significantly differed in the SF over time (pre-operative vs. intraoperative urine samples), exhibiting enrichment in pathogenic bacteria following perioperative antibiotic treatment that were similar to those elevated in the SF gut. Interestingly, kidney stones harboured a microbiota distinct from urine, and this was not dictated by the stone's crystalline composition. CONCLUSIONS: Together these findings suggest that the microbiome of SF is dysfunctionally altered in a multimodal manner, aggravating stone formation. The microbiome at multiple body sites, as an interconnected system, likely plays a far more significant role in nephrolithiasis beyond the dogmatic perspective that O. formigenes colonization is the key to stone prevention. Source of Funding: W. Garfield Weston Foundation © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e144-e144 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kait Al More articles by this author Benjamin Joris More articles by this author John Denstedt More articles by this author John Chmiel More articles by this author Jennifer Bjazevic More articles by this author Gregory Gloor More articles by this author Hassan Razvi More articles by this author Jeremy Burton More articles by this author Expand All Advertisement Loading ...

Influence of microbiological diagnosis on the clinical course of spondylodiscitis

PurposeThis study sought to recognize differences in clinical disease manifestations of spondylodiscitis depending on the causative bacterial species.MethodsWe performed an evaluation of all spondylodiscitis cases in our clinic from 2013–2018. 211 patients were included, in whom a causative bacterial pathogen was identified in 80.6% (170/211). We collected the following data; disease complications, comorbidities, laboratory parameters, abscess occurrence, localization of the infection (cervical, thoracic, lumbar, disseminated), length of hospital stay and 30-day mortality rates depending on the causative bacterial species. Differences between bacterial detection in blood culture and intraoperative samples were also recorded.ResultsThe detection rate of bacterial pathogens through intraoperative sampling was 66.3% and could be increased by the results of the blood cultures to a total of 80.6% (n = 170/211). S. aureus was the most frequently detected pathogen in blood culture and intraoperative specimens and and was isolated in a higher percentage cervically than in other locations of the spine. Bacteremic S. aureus infections were associated with an increased mortality (31.4% vs. overall mortality of 13.7%, p = 0.001), more frequently developing complications, such as shock, pneumonia, and myocardial infarction. Comorbidities, abscesses, length of stay, sex, and laboratory parameters all showed no differences depending on the bacterial species.ConclusionBlood culture significantly improved the diagnostic yield, thus underscoring the need for a structured diagnostic approach. MSSA spondylodiscitis was associated with increased mortality and a higher incidence of complications.

OTEH-2. High-dimensional analysis of spatial immune cell heterogeneity in glioblastoma reveals differences between contrast-enhancing and non-contrast-enhancing tumor rims

BackgroundGlioblastoma (GBM) is the most common primary malignant brain tumor in adults. GBM remains an incurable disease, with a median survival ~20 months. Complex intercellular interactions within the tumor microenvironment and spatial heterogeneity have challenged and impeded therapeutic efficacy. The non-contrast-enhancing (by T1-weighted MRI) rim of GBM is not always safely resectable and represents a major source of recurrence. We hypothesized that differential immune infiltration is an underlying factor of spatial heterogeneity in GBM, particularly in the non-contrast-enhancing tumor rim.MethodsFive patients with newly diagnosed GBM (ages 53–84) were recruited to a device feasibility study (NCT04545177) utilizing an intraoperative high-resolution MRI-based navigation system coupled with the NICO Myriad (a non-ablative semi-automated resection tool) and a coupled automated biological Tissue Preservation System (NICO APS) to sample spatially mapped regions of tumors in a reproducible and minimally destructive manner. We obtained brain tumor tissue from: (a) tumor core, (b) contrast-enhancing tumor rim and (c) non-contrast-enhancing tumor rim. Downstream processing consisted of digestion of tumor tissue (Miltenyi human tumor digestion kit) for subsequent single-cell isolation, viability assessment and immediate staining for multiparametric flow cytometry for immune profiling.ResultsViability varied across sampled regions (median 85%, range 52–100%). With the exception of 1 sample, viability was >70% in all specimens. High-dimensional analysis with 26 marker flow cytometry revealed spatial heterogeneity in the frequency of myeloid-derived suppressor cell subsets, regulatory T cells, CD8+ T cells, as well as expression of T cell activation and exhaustion markers.ConclusionsSemi-automated, spatially mapped intraoperative sampling of GBM with high viability of specimens is feasible and reproducible with the NICO Myriad and APS devices. High-dimensional analysis of immune cells in the GBM microenvironment captured the spatial heterogeneity of GBM. Future studies will expand on these observations by analyzing more patient specimens in combination with multiple omics assays.