Daniel Doykov

Background and Objectives: What led to the development of elastography was the emerging need for a method that could objectively and accurately assess the stiffness of internal structures. As a result, a distinction between normal from pathological tissues becomes possible. Objective: To evaluate non-invasive elastographic techniques, point shear wave elastography (pSWE) and two-dimensional shear wave elastography (2D-SWE), as methods for differentiating simple liver cysts from liver hemangiomas. Materials and Methods—a total of 63 patients—32 with simple liver cysts and 31 with liver hemangiomas were analyzed. The purpose was to determine the values of the average trend (arithmetic mean or median according to the data distribution) as well as the reference intervals of SWV for both methods in the above-mentioned patients. Final diagnoses were confirmed by contrast-enhanced computed tomography (CECT). Results: The pSWE SWV values (median) for simple hepatic cysts showed an average trend of 1.14 m/s, with an upper limit of 3.33 m/s and a lower limit of 0.35 m/s. For 2D-SWE, the average trend for simple hepatic cysts was 1.00 m/s, with an upper limit of 1.54 m/s and a lower limit of 0.65 m/s. For liver hemangiomas, the average trend in pSWE was 1.36 m/s, with an upper limit of 3.22 m/s and a lower limit of 0.57 m/s. For 2D-SWE, the average trend was 1.34 m/s, with an upper limit of 2.27 m/s and a lower limit of 0.80 m/s. Findings in our work mainly serve as reference values. Conclusions: The accurate diagnosis of liver diseases is of paramount importance when it comes to the approach and treatment of individual benign liver lesions. Early diagnosis of focal liver lesions remains a challenging task.

The development of the Gleason grading system has proven to be an irreplaceable tool in prostate cancer diagnostics within urology. Despite the advancements and developments in diagnostics, there remains a discrepancy in the grading process among even the most experienced pathologists. AI algorithms have demonstrated potential in detecting cancer and assigning Gleason grades, offering a solution to the issue of significant variability among pathologists’ evaluations. Our paper explores the evolving role of AI in prostate cancer histopathology, with a key focus on outcomes and the reliability of various AI algorithms for Gleason pattern assessment. We conducted a non-systematic review of the published literature to examine the role of artificial intelligence in Gleason pattern diagnostics. The PubMed and Google Scholar databases were searched to gather pertinent information about recent advancements in artificial intelligence and their impact on Gleason patterns. We found that AI algorithms are increasingly being used to identify Gleason patterns in prostate cancer, with recent studies showing promising advancements that surpass traditional diagnostic methods. These findings highlight AI’s potential to be integrated into clinical practice, enhancing pathologists’ workflows and improving patient outcomes. The inter-observer variability in Gleason grading has seen an improvement in efficiency with the implementation of AI. Pathologists using AI have reported successful outcomes, demonstrating its effectiveness as a supplementary tool. While some refinements are still needed before AI can be fully implemented in clinical practice, its positive impact is anticipated soon.

In recent years spleen stiffness (SS), assessed by point shear wave elastography (pSWE) has been a topic of interest as a more accurate indicator for the diagnosis of liver fibrosis in chronic viral hepatitis. For the first time in Bulgaria, a comprehensive research on the stiffness of the liver and spleen has been performed by pSWE in patients with chronic viral hepatitis, as well as evaluation of their correlation with the histological assessment of liver fibrosis. The aim of the research is to establish spleen and liver stiffness in patients with chronic viral hepatitis and their correlation with intermediate stages of liver fibrosis diagnosed histologically after biopsy. For the period 2018–2020, ninety patients with chronic viral hepatitis B and C (mean age 46.20±14.55) from the department of Gastroenterology, University hospital Kaspela, Plovdiv, Bulgaria, have been examined, by abdominal ultrasound, pSWE of the liver and spleen, histological evaluation of liver fibrosis, data study on the presence of esophageal varices and ascites. The liver stiffness (LS) value distinguishing between F1 and F2 was 1.86 m/s (rs=0.769, 95% CI: 0.652–0.850, p<0.001). The spleen stiffness (SS) value distinguishing between F1 and F2 was 2.95 m/s (rs=0.838, 95% CI: 0.749–0.898, p<0.001). Liver stiffness is significantly affected by BMI, which reduces its diagnostic potential in obese patients. Spleen stiffness measured by pSWE can be used in the diagnosis of intermediate stages of liver fibrosis in patients with chronic hepatitis B and C.

Introduction. Biliary obstruction is a common manifestation of biliopancreatic malignancies, and its relief is an essential part of the treatment algorithm. Currently, there are three techniques to manage malignant biliary obstruction—endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic biliary drainage (PTBD), and endoscopic ultrasound-guided biliary drainage (EUS-BD). ERCP has been adopted as a first-line treatment modality but EUS-BD is gradually emerging as a viable alternative. The aim of the current article is to assess the clinical outcomes of the three nonsurgical biliary drainage procedures. Materials and methods. A total of 102 consecutive patients with unresectable biliopancreatic malignancy inducing biliary obstruction and subjected to palliative treatment by means of ERCP, EUS-BD, or PTBD were retrospectively included in the study. Results. No difference in clinical and technical success of the procedures was found: ERCP—97.2% technical; 88.9% clinical; PTBD—94.4% technical, 72.2% clinical; EUS-BD—90% technical; 83.3% clinical. Adverse events (AEs) and reinterventions were significantly more common in PTBD (38.9% and 52.8%) and ERCP (27.9% and 25%) compared to EUS-BD (10% and 3.3%). Total duration of hospital stay and number of hospitalizations were lower in the EUS-BD compared to PTBD and ERCP groups. Conclusions. In the presence of adequate expertise, EUS-BD may be superior to PTBD and ERCP in achieving and sustaining biliary drainage in the setting of unresectable malignancy.

Introduction: Gallstone disease (GSD) is among the most common disorders worldwide. Gallstones are established in up to 15% of the general population. Laparoscopic cholecystectomy (LC) has become the “gold standard” for treatment of GSD but is associated with a higher rate of certain complications, namely, bile duct injury (BDI). Biliary fistulas (BF) are a common presentation of BDI (44.1% of all patients); however, they are mainly external. Post-cholecystectomy internal BF are exceedingly rare. Case report: a 33-year Caucasian female was admitted with suspected BDI after LC. Strasberg type E4 BDI was established on endoscopic retrograde cholangiopancreatography (ERCP). Urgent laparotomy established biliary peritonitis. Delayed surgical reconstruction was planned and temporary external biliary drains were positioned in the right and left hepatic ducts. During follow-up, displacement of the drains occurred with subsequent evacuation of bile through the external fistula, which resolved spontaneously, without clinical and biochemical evidence of biliary obstruction or cholangitis. ERCP established bilio-duodenal fistula between the left hepatic duct (LHD) and duodenum, with a stricture at the level of the LHD. Endoscopic management was chosen with staged dilation and stenting of the fistulous tract over 18 months until fistula maturation and stricture resolution. One year after stent extraction, the patient remains symptom free. Discussion: Management of post-cholecystectomy BDI is challenging. The optimal approach is determined by the level and extent of ductal lesion defined according to different classifications (Strasberg, Bismuth, Hannover). Type E BDI are managed mainly surgically with a delayed surgical approach generally deemed preferable. Only three cases of choledocho-duodenal fistulas following LC BDI currently exist in the literature. Management is controversial, with expectant approach, surgical treatment (biliary reconstruction), or liver transplantation being described. Endoscopic treatment has not been described; however, in the current paper, it proved to be successful. More reports or larger case series are needed to confirm its applicability and effectiveness, especially in the long term.

Introduction: Numerous studies to date have shown that the development of dysbiotic gut microbiota is a characteristic finding in chronic kidney disease (CKD). A number of uremic toxins progressively accumulate in the course of CKD, some of them generated by the intestinal microbiome, such as indoxyl sulfate (IS) and p-cresyl sulfate (p-CS). They are found to be involved in the pathogenesis of certain complications of uremic syndrome, including low-grade chronic inflammation and oxidative stress. The aim of the present study is to research the serum concentration of IS and p-CS in end stage renal disease (ESRD) patients undergoing conventional hemodialysis, as well as to study the possibilities of influencing some markers of inflammation and oxidative stress after taking a synbiotic. Materials and Methods: Thirty patients with end-stage renal disease (ESRD) undergoing hemodialysis treatment who were taking a synbiotic in the form of Lactobacillus acidophilus La-14 2 × 10¹¹ (CFU)/g and prebiotic fructooligosaccharides were included in the study. Serum levels of total IS, total p-CS, Interleukin-6 (IL-6), and Malondialdehyde (MDA) were measured at baseline and after 8 weeks. Results. The baseline values of the four investigated indicators in the patients were significantly higher—p-CS (29.26 ± 58.32 pg/mL), IS (212.89 ± 208.59 ng/mL), IL-6 (13.84 ± 2.02 pg/mL), and MDA (1430.33 ± 583.42 pg/mL), compared to the results obtained after 8 weeks of intake, as we found a significant decrease in the parameters compared to the baseline—p-CS (6.40 ± 0.79 pg/mL, p = 0.041), IS (47.08 ± 3.24 ng/mL, p < 0.001), IL-6 (9.14 ± 1.67 pg/mL, p < 0.001), and MDA (1003.47 ± 518.37 pg/mL, p < 0.001). Conclusions: The current study found that the restoration of the intestinal microbiota in patients with CKD significantly decreases the level of certain uremic toxins. It is likely that this favorably affects certain aspects of CKD, such as persistent low-grade inflammation and oxidative stress.

Introduction. Mirizzi syndrome (MS) represents a rare clinical entity caused by impaction of one or multiple stones in the infundibulum of the gall bladder or the cystic duct resulting in partial or complete obstruction of the common hepatic or common bile duct (CBD). Though described more than a century ago, MS is still one of the most challenging diseases in the spectrum of biliary pathology. In recent years, endoscopic treatment has become an increasingly popular treatment modality. Patients and methods. Three consecutive patients subjected to cholangioscopy-assisted laser lithotripsy (CA-LL) for postocholecystectomy MS (pMS) were retrospectively evaluated. Case reports. Successful clearance of the cystic duct was achieved in all patients in one or two sessions. One complication in the form of mild cholangitis was observed. Clinical success was 100%. Discussion. According to current research, CA-LL achieves a high rate of ductal clearance and acceptable complication rate in patients with pMS. A 250 µm laser fiber seems to be the optimal choice for CA-LL. Our results suggest that procedure duration is closely associated to the stone size and possibly to the operator experience. In our opinion, upon obtainment of successful ductal clearance and drainage, prophylactic stenting does not improve clinical outcome. Conclusions. Our results demonstrate that CA-LL is a safe and effective treatment for pMS.

Portal hypertension (PH) and esophageal varices (EVs) are a matter of extensive research. According to current Baveno VII guidelines, in patients with compensated advanced chronic liver disease (cACLD), liver stiffness measurement (LSM) < 15 kPa and PLT count > 150 × 10⁹/L, upper endoscopy (UE) is not mandatory, and the emphasis should be set on non-invasive methods for evaluation of clinically significant portal hypertension (CSPH). The aim of this study is to establish whether liver stiffness (LS) measured by 2D-SWE could be used as a predictor for the presence and severity of EVs in cirrhotic patients. In total, 86 patients of whom 32 with compensated liver cirrhosis (cLC) and 54 with decompensated liver cirrhosis (dLC) were examined in the Gastroenterology clinic of University hospital “Kaspela”, Plovdiv, Bulgaria. Each patient underwent LS assessment by 2D-SWE and EVs grading by UE. EVs were detected in 47 (54.7%) patients, 23 (49%) of them were stage 4-high-risk EVs (HREV). The cut-off value for LS that differentiates HREV from the rest was set at 2.49 m/s with 100% sensitivity and 100% specificity (AUC 1.000, CI 0.925). Conclusions: 2D-SWE can be used as a non-invasive method in the assessment of only high-grade esophageal varices. For the other grades, upper endoscopy remains the method of choice.

Non-invasive, ultrasound-based methods for visualizing and measuring tissue elasticity are becoming more and more common in routine daily practice. An accurate diagnosis of malignant and benign tumors is essential for determining the appropriate treatment. Despite the wide use of imaging techniques, the investigation for assessing the elasticity of focal liver lesions and their differentiating is still continuing. Aim: To investigate the value of point shear wave elastography (pSWE) and two-dimensional shear wave elastography (2D-SWE) for the differential diagnosis of benign and malignant focal liver lesions. Materials and Methods: A total of 125 adult patients were included from the Clinic of Gastroenterology of University Hospital Kaspela, Plovdiv city, Bulgaria, in the period from January 2021 to July 2022. Participants were divided into two groups—with benign (hemangiomas) and malignant focal liver lesions (hepatocellular carcinoma). The group with benign lesions included 63 patients and the group with malignant focal liver lesions (FLLs)—62 patients. Point shear wave elastography (pSWE) and two-dimensional shear wave elastography (2D-SWE) integrated in the same ultrasound machine (Esaote MyLab™ 9Exp) were performed for each lesion. Results: Malignant FLLs have significantly higher stiffness in both pSWE (2.52–4.32 m/s, 90% CI: 2.37 to 2.68, 90% CI: 4.19 to 4.55) and 2d-SWE (2.52–4.43 m/s, 90% CI: 2.31 to 2.65, 90% CI: 4.27 to 4.61). Conclusion: 2D-SWE and pSWE could provide complementary data about FLLs. They enable us to conveniently and easily obtain accurate stiffness information of FLLs.

Introduction: A variety of imaging techniques exists for the diagnosis of pancreatic disorders. None of the broadly applied diagnostic methods utilizes elasticity as an indicator of tissue damage. A well-known fact is that both chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDA) are associated with the development of prominent fibrosis (increased tissue stiffness). Purpose: To prospectively assess the accuracy of point shear wave elastography (pSWE) in differentiating between benign and malignant pancreatic diseases, establish a cut-off value for the diagnosis of PDA, and evaluate the influence of certain variables on the obtained results. Materials and methods: The present study included 78 patients who were admitted at the Department of Gastroenterology at the university hospital “Kaspela” between December 2017 and August 2021 for diagnosis and/or treatment of pancreatic disorders. Based on the clinical criteria, diagnostic imaging, and histological findings, patients were divided into the CP and PDA group. The ultrasound based pSWE technique was applied and shear wave velocity (SWV) was measured. The depth of region of interest (ROI) and successful measurement rate were also recorded. Results: The mean ± SD SWV values established through pSWE were 1.75 ± 0.34 m/s and 2.93 ± 0.91 m/s for the CP and PDA, respectively. With a cut-off value of 2.09 m/s, we calculated the sensitivity (Se), specificity (Sp), and accuracy for differentiating between CP and PDA of 89.47%, 91.20%, and 88.60%, respectively. Of the examined variables, BMI and depth of ROI in the CP group and sex in the PDA group showed a statistically significant influence on the obtained results. Conclusions: pSWE may be utilized as a differential diagnostic modality in patients with suspected CP or PDA.