Aleksey A. Ponomarenko

OBJECTIVE: the aim of this study is the effect of PRP application on the outcomes of chronic anal fissure treatment and to analyze the factors associated with the rate of anoderm defect epithelialization. PATIENTS AND METHODS: a single-center prospective randomized controlled trial (NCT07268261) was conducted from September 2023 to November 2025. We compared the outcomes of fissure excision (FE) combined with botulinum toxin type A (BTA) injection at a dose of 40 units and platelet-rich plasma injection (FE+BTA+PRP - study group) versus FE combined with BTA (FE+BTA - control group). After applying the exclusion criteria, 125 patients were included in the final analysis: 60 in the study group and 65 in the control group. Cellular composition of plasma was assessed using a hematology analyzer in 51 (85.0%) of 60 patients in the study group; among them, 29 patients underwent blood collection in two-component tubes (Subgroup A), and 22 patients underwent collection in single-component tubes (Subgroup B). The comparative analysis included assessment of wound epithelialization rate on 15, 30, 45 and 60 postoperative days, analgesic requirements, quality of life according to the SF-36 scale, platelet and leukocyte concentrations in PRP, as well as ROC analysis of the prognostic significance of the platelet profile. RESULTS: on the 60th day, the rate of postoperative wound healing was comparable in both groups, up to 43/60 (71.7%; 95% confidence interval [CI]: 58.6–82.5) cases in the FE+BTA+PRP group and 47/65 (72.3%; 95% CI: 59.8–82.7) cases in the FE+BTA group (p=0.936); on the 15th day, postoperative wound epithelialization was not observed in any patient; on the 30th day, wound healing occurred in 11/60 (18.3%) patients in the FE+BTA+PRP group and in none in the FE+BTA group (p=0.0003); on the 45th day — in 18/60 (30.0%) versus 3/65 (4.6%) patients (p=0.0001), respectively. The rates of wound healing depending on the type of tubes used on the 60th day postoperativ were comparable: in subgroup A (using two-component tubes), healing was observed in 21/29 (72.4%) cases, and in subgroup B (using single-component tubes) - in 16/22 (72.7%) cases; on the 30th day, epithelialization occurred in 11/29 (37.9%) cases in subgroup A and in none in subgroup B (0/22; 0%) (p=0.01). By 45th day the rate of postoperative wound healing increased in both subgroups: up to 51.7% (15/29 cases) with usage of two-component tubes and to 13.6% (3/22 cases) - with single-component tubes (p=0.007). A significant reduction in analgesic requirements and improvement in quality of life were noted in the study group. After centrifugation, the platelet level in two-component tubes was 397 × 10³/μL (346; 481), which was statistically significantly higher compared to single-component tubes at 239 × 10³/μL (106; 374) (p=0.001). The factor that statistically significantly increased the odds of epithelialization in univariate logistic regression analysis was the platelet level on the 30th day (OR=1.01; 95% CI: 1.00–1.02; p=0.008) and on the 45th day (OR=1.01; 95% CI: 1.00–1.01; p=0.007). The ROC analysis confirmed that a platelet concentration ≥452×10⁹/L in PRP is a statistically significant predictor of postoperative wound epithelialization time (p=0.001). CONCLUSION: intraoperative administration of low-leukocyte PRP in the surgical treatment of chronic anal fissure significantly accelerates postoperative wound epithelialization, reduces pain syndrome, and improves patients' quality of life. To optimize healing time, it is preferabli to achieve a platelet concentration in PRP of at least 452 × 10⁹/L.

AIM: to compare laser coagulation of the pilonidal sinus and its excision. P ATIENT S AND METHODS: a retrospective study included 113 patients with chronic inflammation of the pilonidal sinus without abscess, with a track no more than 9 cm. The main group underwent laser coagulation of the ECC, and the controls underwent its excision. The pain level, the healing time of postoperative wounds, and the postoperative relapses rate were assessed from days 2 to 6. The primary point of the study was the rate of wounds epithelialization on day 90. RESULT S: on day 90, wound healing occurred in 60/60 (100.0%) patients of the main group and 39/42 (92.9%) patients of the control group, p = 0.067. In the remaining 3/42 (7.1%) patients of the control group, wounds healed on day 95 in 2/42 (4.8%) cases and on day 240 in 1/42 (2.4%). The median duration of healing of postoperative wounds was 45 (35; 60) days in the main group and 85 (65; 90) days in the control group, p < 0.001. Recurrence of the disease occurred in 3/60 (5.1%) cases in the main group and in 2/42 (4.8%) cases in the control group, p = 0.104. CONCLUSION: laser coagulation is a highly effective and safe method of treating uncomplicated forms of pilonidal disease. The protocol of laser exposure and postoperative management has demonstrated its convenience and a good early result. It can be used as a variant of laser coagulation of the epithelial coccygeal passage.

OBJECTIVE: to evaluate the efficacy of PRP therapy following excision of chronic anal fissure (CAF) combined with pharmacological relaxation of the internal anal sphincter using 40 units of botulinum toxin type A (BTA). PATIENTS AND METHODS: single-center prospective randomized controlled trial (NCT07268261) was held between September 2023 and November 2025comparing outcomes of fissure excision (FE) combined with 40 units of BTA plus platelet-rich plasma injection (FE + BTA + PRP — study group) versus FE with BTA alone (FE + BTA — control group).142 patients were randomized during this period: 70 in FE + BTA + PRP group and 72 in FE + BTA group. 125 patients were included in the final analysis after applying exclusion criteria: 60 in the study group and 65 in the control group. During preoperative and postoperative period patients underwent control examinations, pain intensity assessment using the visual analog scale (VAS), profilometry, and evaluation of transient fecal incontinence using the Wexner scale. The primary end point was the rate of wound epithelialization at 60 days post-surgery. RESULTS: on the 60 ^th days, wound healing rates were comparable between both groups: 43/60 (71.7%; 95% confidence interval [CI]: 58.6–82.5) in the FE + BTA + PRP group versus 47/65 (72.3%; 95% CI: 59.8–82.7) in the FE + BTA group (p = 0.936). However, on the 15th days, no patients had epithelialized wounds; on the 30th days, wound healing occurred in 11/60 (18.3%) patients in the FE + BTA + PRP group versus none in the FE + BTA group (p = 0.0003); on the 45th days — in 18/60 (30.0%) versus 3/65 (4.6%) patients respectively (p = 0.0001). No postoperative complications developed in any patient. Transient fecal incontinence on the 30th days was observed in 12/60 (20.0%) patients in the studied group and 10/65 (15.4%) in the control group (p = 0.498); on the 60th days — in 5/60 (8.3%) and 2/64 (3.1%) patients, respectively (p = 0.262). Pain intensity during the day and during defecation in the postoperative period was comparable between two groups throughout the observation period, except of day 10 (during defecation, p = 0.049) and day 12 (during the day, p = 0.036; during defecation, p = 0.035), with lower scores in the control group; by day 60, pain was successfully relieved in almost all patients in both groups. According to profilometry data on the 30th days internal anal sphincter (IAS) spasm persisted in 15/48 (31.3%) patients in the study group and 10/51 (19.6%) in the control group (p = 0.183); on the 60th days — in 15/45 (33.3%) and 11/49 (22.4%) patients, respectively (p = 0.239). No statistically significant differences were achieved in favor of the study group regarding the number of days of temporary disability — 15 (11; 22) days in the FE + BTA + PRP group versus 20 (13; 27) in the FE + BTA group (p = 0.079). Female gender was identified as a factor significantly increasing the odds of absence of epithelialization on the 30th days in univariate logistic regression analysis (odds ratio [OR] = 3.95; 95% CI: 1.09–14.37; p = 0.037). On the 45th days, in addition to gender (OR = 3.29; 95% CI: 1.26–8.61; p = 0.015), significant factors were: treatment method in favor of the FE + BTA + PRP group (OR = 0.11; 95% CI: 0.03–0.41; p = 0.0009); age (OR = 1.07; 95% CI: 1.01–1.13; p = 0.015); and presence of constipation (OR = 5.14; 95% CI: 1.43–18.53; p = 0.013). On the 60th days, only female gender was statistically significantly associated with non-healing wound (OR = 3.22; 95% CI: 1.22–6.66; p = 0.019). No factors influencing the presence of transient fecal incontinence were identified. CONCLUSION: the use of platelet-rich plasma combined with BTA injection and FE in the treatment of CAF does not increase the rate of postoperative wound epithelialization at 2 months after surgery; however, it offers an advantage by increasing the rate of epithelialization at 30 and 45 days. At the same time this method does not affect the incidence of postoperative complications, pain intensity, functional treatment outcomes, or social and occupational rehabilitation of patients.

AIM: to present the results of molecular genetic testing in patients with suspected juvenile polyposis syndrome (JPS). PATIENTS AND METHODS: molecular genetic testing was performed on 30 patients from 28 families (one family had three affected relatives) who were followed from 2012 to 2024. DNA was isolated from patients’ peripheral blood leukocytes. The initial step involved Sanger sequencing of the SMAD4 (NM_005359.6) and BMPR1A (NM_004329.3) genes, followed by screening for large rearrangements using MLPA (Multiplex Ligation-dependent Probe Amplification). Finally, patient DNA was analyzed by whole-exome sequencing (WES), with confirmation of identified variants by Sanger sequencing. RESULTS: pathogenic and likely pathogenic variants in the BMPR1A and SMAD4 genes were identified in 18 out of 28 families (64.3%). In the BMPR1A gene, 11 out of 18 (61.1%) germline variants were found, including three large deletions. In the SMAD4 gene, 7 out of 18 (38.9%) germline variants were detected, including one large deletion and one large duplication. Thus, 5 out of 18 (27.8%) germline variants in these genes were large rearrangements. In five families, previously unreported germline variants were identified (three in BMPR1A and two in SMAD4), all classified as likely pathogenic. CONCLUSION: all patients with suspected juvenile polyposis syndrome should be tested for SMAD4 and BMPR1A mutations using Sanger sequencing and MLPA. If the result is negative, high-throughput sequencing should be employed. For patients with 20 or more adenomatous colorectal neoplasms but no pathogenic/likely pathogenic variants in the APC and MUTYH genes, it is advisable to proceed directly to whole-exome sequencing.

AIM: to assess the outcomes of chronic anal fissure treatment using lateral internal sphincterotomy with and without fissure excision.PATIENTS AND METHODS: a prospective, single-center, randomized study included 107 patients with chronic anal fissure (CAF) older than 18 years, without severe comorbidities, rectal fistulas, grade 3–4 hemorrhoids, or clinical manifestations of anal sphincter insufficiency (ASI) from October 2021 to October 2023. Patients were randomized using a random number generator into two groups: 56 patients in the main group underwent lateral internal sphincterotomy (LIS), and 51 patients in the control group underwent LIS combined with fissure excision (LIS + FE). Immediate results were analyzed per protocol in 50 patients per group. Late outcomes were assessed in 44 patients in the main group and 43 patients in the control group. Primary endpoint: epithelialization of the defect on the 60th day after surgery. Secondary endpoints: epithelialization of the defect on the 15th, 30th, and 45th days postoperatively, incidence and structure of complications, pain syndrome (VAS from day 1 to day 60), profilometry indicators on the 30th, 60th, and 365th days postoperatively, time of temporary disability, incidence of ASI on the 30th, 60th, and 365th days postoperatively (Wexner's scale), and recurrence rate.RESULTS: by day 60, the anal fissure had epithelialized in 47/50 (94%) patients in the main group, while the postoperative wound had healed in 48/50 (96%) patients in the control group (p = 1). On days 15, 30, and 45, the epithelialization rate of the anal fissure was significantly higher than that of the postoperative wound. Fissure excision increased the likelihood of an unhealed postoperative wound on day 30 (OR 18.7 95% CI: 5.8–60.4; p < 0.0001) and on day 45 (OR 5.23 95% CI: 1.97–13.8; p = 0.0008). In the main group, post-defecation pain intensity was significantly lower than in the control group during the first 30 days (p < 0.0001). On the 30th postoperative day, gas incontinence was reported by 9/50 (18.0%) patients in the main group and 17/50 (34%) in the control group (p = 0.1), while on the 60th day, 2/50 (4.0%) patients in the LIS group and 3/50 (6%) in the LIS + FE group (p = 1.0) reported gas incontinence. The median Wexner score on the 30th postoperative day was 1 (1; 1) in the LIS group and 2 (1; 3) in the LIS + FE group (p = 0.03). Univariate analysis showed that factors increasing the likelihood of anal incontinence on the 30th postoperative day were age (OR = 1.03; 95% CI: 1.0–1.07) and childbirth history (OR = 12.3; 95% CI: 1.3–118.3). Fissure excision had a greater negative impact on patients' quality of life in the early postoperative period. The median Hemo-Fiss score on the 30th postoperative day was 5.5 (0; 13) points in the main group and 11 (5; 20) points in the control group (p = 0.02). The median time of temporary disability was 9 (6; 11) days in the LIS group and 15.5 (12; 23) days in the LIS + FE group (p = 0.0006). In the long-term postoperative period (up to 1 year), the groups were fully comparable in complication rates and nature. Recurrence occurred in 1/44 (2.2%) patients in the main group and 2/43 (4.6%) patients in the control group (p = 1.0). A rectal fistula was identified in 2/44 (4.5%) patients in the main group and 1/43 (2.6%) in the control group. ASI was observed only in the control group in 1/43 (2.3%) patients. Profilometry measurements showed that maximum resting anal canal pressure was 102 (89; 111) mmHg in the main group and 96 (85; 112) mmHg in the control group (p = 0.08). The mean resting anal canal pressure was 55 (52; 59) mmHg in the LIS group and 52 (42; 58) mmHg in the LIS + FE group (p = 0.1).CONCLUSION: performing LIS without fissure excision prevents long-healing wound in the anal canal, reduces pain intensity, decreases the severity of anal incontinence, improves quality of life, and shortens temporary disability. Avoiding fissure excision does not lead to worsening of late outcomes.

AIM: to assess efficacy of botulinum toxin type A (BTA) at a dosage of 80 units for chronic anal fissure (CAF) without excision.PATIENTS AND METHODS: single-center prospective randomized controlled trial (NCT05598164) was held between September 2022 and December 2024 in order to compare isolated usage of BTA (main group) at a dosage of 80 units with its combination with excision of the fissure — BTA + EF (control group) for CAF. One hundred sixty-seven were randomized — 86 were included in main group and 81 — in control one. After application of exclusion criteria 126 patients were included in final analysis: 65 in group of BTA only and 61 in group of its combination with EF. Control examination, pain syndrome intensity according to visual-analogue scale (VAS), profilometry and assessment of transitory anal incontinence according to Wexner scale were done in pre- and postoperative period. The primary endpoint was epithelization of defect (for the main group) or postoperative wound (for the control group) on 60th day after surgery.RESULTS: on the 60th day postoperative defect healed in 46/59 (78.0%; 95% confidence interval (CI): 65.2–87.7) patients in main group vs. 34/50 (68.0%; 95% CI: 53.3 — 80.5) patients for postoperative wound in control group (р = 0.3). At the same time, on the 15th day defect healed in 12/65 (18.4%) patients in BTA group, whereas no one's postoperative wound healed in group BTA + EF (р = 0.0003); on the 30th day — in 18/59 (30.5%) vs. 1/53 (1.9%) patients(р < 0,0001); on the 45th day — in 31/57 (54.4%) vs. 3/52 (5.8%) patients(р < 0.0001). The rate of postoperative complications was 23/65 (35.4%) in main group and 23/61 (37.7%) in controls (р = 0.8). On the 30th day transitory anal incontinence was detected in 15/60 (25.0%) patients in BTA group and in 18/53 (34.0%) in combinations of its injection with EF (p = 0.3); on the 60th day — in 7/60 (11.7%) and 9/51 (17.6%) patients (p = 0.4); external hemorrhoids thrombosis developed in 2/65 (3.1%) patients of main group and in 2/61 (3.3%) of control group (p = 1.0); intrasphincter fistula — in 5/60 (8.3%) and 3/50 (6.0%) patients (p = 0.7). Intensity of pain syndrome during the day and while defecation began to decrease in patients of main group from the 1st day after surgery, whereas it increased and returned to pre-operative level in control group by the 3d day, where remained till the 9th day, only after this it decreased. Significant differences between groups were revealed to 48–49th days. According to profilometry, spasm of internal anal sphincter (IAS) remained in 22/56 patients of main group and in 16/52 patients of control group; on 60th day — in 22/52 (39.3%) and 8/50 (16.0%) patients relatively (p = 0.004). In group of BTA there were statistically significantly fewer days of disability than in group of combination BTA with EF — 7 (6; 15) vs. 20 (15; 30) days. Method of treatment BTA + EF became significant factor, increasing chances of no epithelization on the 30th (odds ratio (OR) = 22.8; 95% CI: 2.93–178.0; р = 0.003) and 45th (OR = 19.5; 95% CI: 5.43–69.8; р < 0.0001) days. On the 60th day presence of IAS spasm was statistically significantly associated with non-healing (OR = 2.68; 95% CI: 1.08–6.66; р = 0.034). The factors which could influence the existence of transitory anal incontinence, were not detected.CONCLUSION: refusal from EF while BTA's use at a dosage of 80 units allows to achieve defect epithelization on early post-operative period, lower intensity of pain syndrome and significantly decrease time of temporary disability.

AIM: to assess risk factors for bowel cancer associated with Crohn's disease, as well as to assess the clinical features of the combined pathologies.PATIENTS AND METHODS: retrospective study included 1,478 medical records of patients with Crohn's disease in 2020–2024. Eleven patients with bowel cancer were identified.RESULTS: history analysis revealed that colorectal cancer developed mainly in patients with a long history of the CD, in whom inflammatory changes in the intestine were detected at a young age, and complications of the disease were noted as well (fistulas, strictures, perianal manifestations). For CD, patients received therapy with various genetically engineered biological agents. When colorectal cancer was detected, the tumor was localized in the colon or rectum, and had the histological structure of adenocarcinoma. After treatment (neoadjuvant chemoradiation therapy, adjuvant chemotherapy, surgery), patients were followed up for 0–16 months, during this period, relapses of Crohn's disease and colorectal cancer were not detected.CONCLUSION: further studies are needed to assess the risk factors for the development of bowel cancer in the presence of Crohn's disease, the characteristics of the course of Crohn's disease after diagnosed bowel cancer, and the development of approaches to the diagnosis, treatment, and prevention of such conditions.

AIM: to reveal biofilms in chronic anal fissure (CAF) bacterial composition.PATIENTS AND METHODS: patient A., 40 years old, with chronic posterior and anterior anal fissures with sphincter spasm underwent a lateral subcutaneous sphincterotomy with excision of the CAFs. Before the operation swabs were taken from fissures for microbiology. Removed specimens were placed in fixing solutions. Microbiological studies including 16S rRNA gene sequencing and MALDI-ToF mass spectrometry of isolated cultures were carried out to assess the bacterial composition of CAFs. Microscopic studies which included scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to search for the biofilm location of microorganisms. Conclusions about the presence of biofilms were made during the comparison of photographs with reliable images described in the literature.RESULTS: a wide variety of bacteria (56 genera) was detected in the tissues forming the CAF based on sequencing of 16S rRNA genes; swab's mass spectrometry revealed only E. coli and P. anaerobius in significant concentrations. Using SEM on one of the sections of the excised CAF were found biofilms containing bacterial cells immersed in an extracellular matrix (which size was within the limits of 2 microns); similar structures weren't detected outside the CAF. On TEM an accumulation of bacterial cells, surrounded by an extracellular polymer matrix, what was interpreted as a biofilm of gram-negative bacteria, was identified. After 7 months, the patient retained a non-healing postoperative wound in the area of the previously excised posterior fissure. After repeated sowing, E. coli and S. gallolyticus were obtained in significant concentrations. Excision of the scarred edges of the wound and the prescribed conservative treatment allowed the wound to epithelize within 3 weeks.CONCLUSION: the results show that microbial biofilms can be localized in the CAF. Further researches are needed for reliable conclusions about biofilm organization in CAF and their effect on pathological and reparative processes.

AIM: to clarify endoscopic features that differentiates juvenile polyps from other types of polyps in patients with juvenile polyposis syndrome.PAIENTS AND METHODS: the retrospective cohort study included 30 patients who met the clinical criteria for juvenile polyposis syndrome in Jan 2012 — Dec 2024. A total of 1026 colorectal neoplasms were analysed comparing endoscopic and morphological images. Endoscopic features that have a significant impact on the determination of juvenile polyps were assessed. The following factors were estimated: size, site, Paris classification criteria, polyp surface, discrepancy with the adenomatous pattern, presence of whitish pits.RESULTS: the most important features are smooth surface, distinguished from adenomatous polyps include discrepancy with the adenomatous surface pattern according to the classifications of Kudo-Sano, as well as the presence of whitish pits of a round, irregular or elongated shape (p < 0.001). These criteria allow to determine with a probability of up to 80% that the detected neoplasm will be a juvenile polyp. The endoscopic diagnostic method has a high sensitivity of 93.9% (95% CI: 89.1–97.0) and a negative predictive value of 90.7% (95% CI: 83.5–95.4) in detecting juvenile polyps.CONCLUSION: endoscopic features of juvenile polyps (smooth surface, the discrepancy with the adenomatous surface pattern according to the classifications of Kudo S. and Sano Y., as well as the presence of whitish pits of a round, irregular or elongated shape) were identified.

BACKGROUND: to find predictive value of KRAS gene’s copy number variation (CNV_KRAS) to anti-EGFR therapy.PATIENTS AND METHODS: a prospective cohort single-center study included 150 patients, 103 patients with colorectal cancer (CRC) and wild-type RAS/BRAF, 39 patients with colorectal cancer with somatic mutations in the KRAS gene, as well as 8 non-oncological patients (as normal controls). CNV_KRAS was determined using digital droplet PCR.RESULTS: the clinically significant CNV_KRAS level of ≥ 9 copies established for a refusal of targeted anti-EGFR therapy. The incidence of clinically significant CNV_KRAS level in patients with wild-type RAS/BRAF was 17% (the first group of patients). Incidence of clinically significant CNV_KRAS level in patients with mutations in the KRAS gene was 3% (the second group of patients). At the I stage of CRC clinically significant CNV_KRAS was not detected in either the first or second group; at the stage II of CRC in the first group — in 14% of patients (3/22), and in the second group — not detected; at the stage III of CRC in the first group — in 21% of patients (8/39), and in the second group of patients — not detected; at the stage IV of CRC in the first group — in 17% (6/35) of patients, and in the second group of patients — in 5% (1/20). Tumor DNA was analyzed in 10 patients with the stage IV CRC from the first group who received anti-EGFR therapy to find out the clinically significant level of CNV_KRAS. Disease control was achieved in 7 out of 10 patients. The median CNV_KRAS score in the remaining three patients was higher than in the disease control group, 9.2 (9.05, 10.10) and 5.38 (4.77, 7.35) (p = 0.017).CONCLUSIONS: detection of CNV_KRAS level of ≥ 9 copies in a malignant colon tumor is a contraindication to targeted therapy. This phenomenon occurs significantly more often in patients without somatic mutations in the RAS genes (KRAS, NRAS) and BRAF, than in patients with point mutations in the KRAS gene (p = 0.02).