EUS-guided FNA and biopsy for cytohistologic diagnosis of gallbladder cancer: a multicenter retrospective study.

BACKGROUND AND AIMS: EUS-guided FNA and biopsy (EUS-FNAB) is a standard diagnostic procedure for pancreatic masses but not gallbladder (GB) cancer (GBC). The aim of this study was to investigate the efficacy and safety of EUS-FNAB for patients with suspected GBC. METHODS: Data were analyzed from patients who underwent EUS-FNAB for suspected GBC in 3 hospitals between 2010 and 2023. The diagnostic performance and safety of EUS-FNAB according to characteristic factors were calculated and compared. RESULTS: Of 170 patients, 163 had GBC. EUS-FNAB samples were obtained from the GB in 125 patients and sites other than the GB in 45 patients. The overall sensitivity, specificity, and accuracy were 83.4%, 100%, and 84.1%, respectively. The sensitivity and accuracy for patients with GB samples were 80.8% and 81.6%; for patients without GB samples, these values were 90.7% and 91.1%. The sensitivity and accuracy were higher with fine-needle biopsy needles than with FNA needles and with ≤22-gauge needles than with 25-gauge needles. However, no significant differences were observed between the GB and lymph node samples. GB lesions <40 mm in size, wall-thickening type, fundal location, absence of extensive liver invasion, and distant metastasis were more frequent in patients without GB samples than in patients with GB samples. Four mild bleeding events were the only reported adverse events. CONCLUSIONS: EUS-FNAB was safe and showed high diagnostic performance for patients with suspected GBC, regardless of the target site. When appropriate GB targeting is difficult, targeting the lymph nodes would be a good strategy with comparable outcomes.

Diagnostic performance of endoscopic ultrasound elastography for differential diagnosis of solid pancreatic lesions: A propensity score-matched analysis.

BACKGROUND: Endoscopic ultrasound-elastography (EUS-EG) is a non-invasive complementary diagnostic method for differential diagnosis of solid pancreatic lesions (SPL). However, the optimal strain ratio (SR) value and diagnostic performance of EUS-EG have not yet been determined in pancreatic neuroendocrine neoplasm (PNEN), mass-forming pancreatitis (MFP), and pancreatic ductal adenocarcinoma (PDAC). We aimed to determine the optimal SR value in EUS-EG for differential diagnosis of SPLs. METHODS: Patients who underwent EUS-EG for SPL evaluation between July 2016 and June 2019 were retrospectively investigated. Patients were divided into three groups based on the final diagnosis (PNEN, MFP, or PDAC). Patient demographics, characteristics of SPL, and EUS-EG were compared. RESULTS: The mean (± standard deviation) SR value for each group were 11.85 ± 7.56 (PNEN, n = 10), 11.45 ± 5.97 (MFP, n = 37), and 22.50 ± 13.19 (PDAC, n = 87). Multinomial logistic regression analysis revealed that an increase of SR value was significantly associated with PDAC (PNEN versus PDAC, p = 0.0216; MFP versus PDAC, p = 0.0006). The optimal cut-off value for differential diagnosis was confirmed as 17.14 after propensity score matching. CONCLUSIONS: We provided the optimal cut-off SR values for differential diagnosis between MFP and PDAC. EUS-EG can be used as a supplementary diagnostic method in the diagnosis of SPLs. (Clinical trial registration number: https://cris.nih.go.kr/cris: KCT0002082).

Covered versus uncovered double bare self-expandable metal stent for palliation of unresectable extrahepatic malignant biliary obstruction: a randomized controlled multicenter trial.

BACKGROUND AND AIMS: In a recent randomized controlled trial, a double bare metal stent (DBS) showed better stent patency than single-layer metal stents. However, clear evidence comparing the efficacy of uncovered (UCDBS) and partially covered (PCDBS) DBSs for distal malignant biliary obstruction (MBO) is lacking. Therefore, we compared the clinical outcomes including stent patency of UCDBSs versus PCDBSs. METHODS: A multicenter, randomized study was performed in patients with distal MBO. The primary endpoint was stent patency. Secondary endpoints were the proportion of patients with patent stents at 6 months, risk factors for stent dysfunction, overall survival, technical and clinical success rates of stent placement, and other adverse events (AEs). RESULTS: Among 258 included patients, 130 were randomly assigned to the PCDBS group and 128 to the UCDBS group. The mean duration of stent patency of the PCDBS (421.2 days; 95% confidence interval [CI], 346.7-495.7) was longer than that of the UCDBS (377.4 days; 95% CI, 299.7-455.0), although total stent dysfunction and stent dysfunction within 6 months were not different between groups. Multivariate analysis indicated that chemotherapy after stent placement was a significant factor for overall survival (hazard ratio, .570; 95% CI, .408-.796) and had a marginal impact on stent patency (hazard ratio, 1.569; 95% CI, .923-2.667). There were no remarkable differences in AEs, including pancreatitis, cholecystitis, and stent migration, between the 2 groups. CONCLUSIONS: The use of PCDBSs compared with UCDBSs in patients with distal MBO has unclear benefits regarding stent patency and overall survival, although PCDBSs have a lower rate of tumor ingrowth. (Clinical trial registration number: NCT02937246.).

Comparison of contrast-enhanced versus conventional EUS-guided FNA/fine-needle biopsy in diagnosis of solid pancreatic lesions: a randomized controlled trial.

BACKGROUND AND AIMS: Contrast-enhanced harmonic EUS (CEH-EUS) is useful in the differential diagnosis of solid pancreatic lesions (SPLs). However, there is lack of verification about the usefulness of CEH-EUS-guided FNA/fine-needle biopsy (FNB) sampling. This study aimed to investigate the usefulness of CEH-EUS-guided FNA/FNB sampling without on-site cytopathology. METHODS: Patients with SPLs were prospectively enrolled and randomly assigned (1:1) to 2 parallel groups, the interventional group (CEH-EUS) or the control group (conventional EUS). The diagnostic sensitivity and optimal number of needle passes for pathologic diagnosis were investigated and compared between groups. RESULTS: Two hundred forty patients were enrolled from March 2016 to September 2019, with 120 patients assigned to each group. Pancreatic malignancies and neuroendocrine tumors were found in 202 (90.83%) and 9 (3.75%) patients, respectively. There was no statistically significant difference between the groups in terms of age, sex, lesion size (30.96 ± 12.09 mm in the CEH-EUS group vs 33.09 ± 16.39 mm in the conventional EUS group; P = .252), lesion location, adverse event rate, and disease distribution. The diagnostic sensitivity values in the CEH-EUS and conventional EUS groups were 85.8% and 88.3%, respectively (P = .564). All patients in the conventional EUS group and most in the CEH-EUS group received a pathologic diagnosis within 3 needle passes. CONCLUSIONS: Diagnostic sensitivity for SPLs was not different between the CEH-EUS and conventional EUS groups, and no independent factors were found that could improve diagnostic sensitivity. CEH-EUS-guided FNA/FNB sampling does not need to be used routinely and may be selectively considered for small, indeterminate lesions. (Clinical trial registration number: KCT 0001840.).

Antimicrobial and hand hygiene effects of Tea Tree Essential Oil disinfectant: A randomised control trial.

BACKGROUND: Hand hygiene is paramount in preventing healthcare-associated infections in medical environments and the spread of infectious diseases in non-medical environments. AIMS: This study used a randomised controlled trial to investigate the effects of a tea tree (Melaleuca alternifolia) oil disinfectant on hand disinfection and skin condition. METHODS: A tea tree oil group received 5 mL of 10% tea tree oil disinfectant mixed in a ratio of 2:2:1:15 of Melaleuca alternifolia oil, solubiliser, glycerin and sterile distilled water. Data collection took place between April 9 and April 13, 2018. The subjects were 112 healthy adults. An alcohol group received 2 mL of a gel-type hand sanitiser comprising 83% ethanol used without water; a benzalkonium chloride group received 0.8 mL of a foam-type hand sanitiser containing benzalkonium chloride used without water and a control group received no treatment. Subjective skin condition, transepidermal water loss and adenosine triphosphate were assessed, and a microbial culture test was performed following treatment. RESULTS: The general characteristics and the pretreatment dependent variables did not differ significantly by group. Posttreatment adenosine triphosphate log10 values significantly differed across all four groups (F = 3.23, P = .025). Similarly, posttreatment bacterial density log10 values differed significantly across the tea tree oil, alcohol, benzalkonium chloride and control groups (F = 91.71, P < .001). CONCLUSION: The study confirmed that tea tree oil disinfectant is effective for hand disinfection. Accordingly, tea tree oil disinfectants may be introduced to nursing practice as a new hand hygiene product to prevent and reduce healthcare-associated infections.

Clinical features and outcomes of hypertriglyceridemia-induced acute pancreatitis: Propensity score matching analysis from a prospective acute pancreatitis registry.

BACKGROUND: Hypertriglyceridemia (HTG) is a well-known cause of acute pancreatitis (AP) and elevation of serum triglycerides (TG) to ≥1000 mg/dl is strongly indicative of HTG-induced AP (HTG-AP). HTG-AP is potentially associated with persistent organ failure and poor prognosis. Here, we compared differences in clinical features and outcomes between patients with HTG-AP and patients with AP due to other causes. METHODS: A prospective AP registry was constructed in Gil Medical Center between June 2014 and May 2018. In total, 499 patients with AP were included for whom serum TG data at admission were available. RESULTS: HTG-AP was present in 52 patients (10.4%); these patients were younger than patients with AP due to other causes (39.62 ± 10.12 vs. 51.62 ± 17.41, p < 0.001). After propensity score matching adjusted by age, the factors associated with severity were more common in the HTG-AP group; these factors included the presence of systemic inflammatory response syndrome, Ranson's score ≥3, acute physiology, age, chronic health evaluation (APACHE) II score ≥8 at admission, and C-reactive protein level >10 mg/dl after 24 h of hospitalization. There were no significant differences in complications or severity based on the revised Atlanta classification 2012. In addition, recurrence was more frequent in the HTG-AP group (25.0% vs. 6.4%, p < 0.001). CONCLUSION: HTG-AP occurred in younger patients and showed more frequent recurrences than AP with other causes. Although factors related to severe feature were more common in HTG-AP during early phase, overall severity and prognosis were not different between the two groups.

G protein-coupled estrogen receptor 1 expression in normal myometrium, leiomyoma, and adenomyosis tissues of premenopausal women.

To verify the different expression of G protein-coupled estrogen receptor 1 (GPER1) among normal uterine, leiomyoma, and adenomyosis tissues. Normal uterine, leiomyoma, and adenomyosis tissue samples were obtained from women aged 35-52 years from a tertiary university hospital. The tissue samples were subjected to immunohistochemical, Western blot, and reverse-transcription polymerase chain reaction (RT-PCR) analyses of GPER1. GPER1 protein expression was confirmed in the tissues by immunohistochemical and Western blot analyses and compared with GPER1 mRNA levels using RT-PCR. GPER1 was detected in the tissue samples of leiomyoma and adenomyosis, which are estrogen-dependent diseases. GPER1 expression was similar between normal uterine and leiomyoma tissues but was reduced in adenomyosis tissue. The level of phosphorylated extracellular signal-regulated kinases 1/2 was lower and higher in leiomyoma and adenomyosis tissues, respectively, than in normal tissue, but the differences among the groups were not statistically significant. Our immunohistochemical, Western blot, and RT-PCR results suggest that GPER1 expression is involved in cell proliferation in leiomyoma and in cell invasion and migration in adenomyosis. Functional studies of GPER1 involving larger sample sizes should be performed to confirm the adenomyosis and leiomyoma disease mechanisms and eventually to develop new therapeutic interventions for these diseases.

Mucin gene polymorphisms are associated with endometriosis in Korean women.

OBJECTIVE: Mucin family members mucin 1 (MUC1) and mucin 4 (MUC4) play an important role in transformation and adhesion, and are known markers for the detection of cancer. However, the pathophysiology of endometriosis associated with the mucin gene is unclear. In this study, we analyzed the relationship between MUC1 and MUC4 single-nucleotide polymorphisms (SNPs) and the risk for endometriosis. METHODS: We performed a case-controlled study of 29 endometriosis clinical samples and 27 functional cysts as control. Sixteen SNPs (rs145224844, rs139620330, rs144273480, rs1611770, rs146141676, rs201798179, rs201815857, rs199840128, rs200788986, rs141460657, rs183700327, rs199768496, rs191544901, rs200639498, rs148332231, and rs11465209) of MUC1 gene and eight SNPs (rs1104760, rs1106502, rs882605, rs2291651, rs2291652, rs2291653, rs2291654, and rs375068067) of the MUC4 gene were identified. We amplified SNP sites by polymerase chain reaction (PCR) using specific primer sets followed by DNA sequencing. RESULTS: The single mutation analysis of MUC4 showed that MUC4 mutations had no effect on the risk for endometriosis, but the frequencies of haplotypes [T/T + T/T + C/C] (rs2291653, 2291654 and rs375068067) were associated with endometriosis. CONCLUSION: The MUC1 genotype may not be correlated with endometriosis susceptibility. However, MUC4 polymorphisms are associated with the risk for endometriosis in Korean women.

The safety of newly developed automatic temperature-controlled endobiliary radiofrequency ablation system for malignant biliary strictures: A prospective multicenter study.

BACKGROUND AND AIMS: Catheter-based endobiliary radiofrequency ablation (RFA) is an endoscopic local treatment for patients with malignant biliary stricture (MBS). However, excessive heating of the bile duct by the current RFA system can induce serious complications. Recently, a new RFA system with automatic temperature control was developed. In the present study, we examined the safety of the new RFA system in patients undergoing endobiliary RFA for extrahepatic MBS. METHODS: This prospective, multicenter study enrolled patients with unresectable or inoperable extrahepatic (> 2 cm from the hilum) MBS. Endobiliary RFA was performed using a newly developed RFA catheter (ELRA™, STARmed, Goyang, Korea) at a setting of 7 or 10 W for 120 s and with a target temperature of 80°C. A self-expandable metallic stent was inserted after endobiliary RFA. The rate of procedure-related adverse events was assessed. RESULTS: The 30 patients were enrolled in this study. Cholangiocarcinoma was diagnosed in 19 patients, pancreatic cancer was found in 9, and gallbladder cancers were recorded in 2. The mean stricture length was 22.1 ± 6.6 mm. Post-procedural adverse events occurred in three patients (10.0%; 2 mild pancreatitis and 1 cholangitis) without hemobilia and bile duct perforation. The pancreatitis and cholangitis resolved with conservative treatment. The cumulative duration of stent patency and survival were 236 and 383 days, respectively. CONCLUSIONS: Automatic temperature-controlled endobiliary RFA using a newly developed catheter was safely applied in patents with extrahepatic MBS. Further prospective studies are needed to confirm the efficacy of endobiliary RFA for MBS.

Long-term results of temperature-controlled endobiliary radiofrequency ablation in a normal swine model.

BACKGROUND AND AIMS: Endobiliary radiofrequency ablation (EB-RFA) is a new adjunctive method for biliary drainage restoration. However, a concern remains about long-term adverse events of this procedure, such as biliary stricture, perforation, and hemorrhage. Therefore, we aimed to assess the long-term effects of in vivo EB-RFA in a swine model. METHODS: Six mini-pigs were divided into 2 groups: 10-W/33-mm EB-RFA and 7-W/18-mm EB-RFA. Endoscopic retrograde cholangiography-guided temperature controlled EB-RFA (80°C, 7-10 W, 120 seconds) was performed. After 28 days all mini-pigs underwent follow-up ERC and were killed to assess the long-term effects of EB-RFA. RESULTS: All mini-pigs developed biliary stricture (median length, 10.5 mm; range, 6-15) with jaundice (total bilirubin, 5.84 mg/dL; range, 4.3-9.2) and purulent bile at 1 month after EB-RFA. A significant difference was found in the length of stricture on cholangiogram between the 10 W/33-mm and 7 W/18-mm EB-RFA groups (median, 14 vs 6 mm; P = .034); however, no differences were found in the width of the stricture and laboratory findings. Histologic examination revealed marked thickening of bile duct with severe damage of whole layers replaced with reactive myofibroblastic proliferation, dense collagen laydown, chronic and acute inflammation, and fat necrosis. However, long-term adverse events, such as perforation or hemorrhage, were not found. CONCLUSIONS: As a long-term result of EB-RFA, segmental biliary stricture with cholangitis develops in proportion to the power/length of the RFA electrode. Therefore, biliary stents should be placed to maintain biliary drainage after EB-RFA.

The efficacy of real-time colour Doppler flow imaging on endoscopic ultrasonography for differential diagnosis between neoplastic and non-neoplastic gallbladder polyps.

OBJECTIVES: We evaluated the usefulness of real-time colour Doppler flow (CDF) endoscopic ultrasonography (EUS) for differentiating neoplastic gallbladder (GB) polyps from non-neoplastic polyps. METHODS: Between August 2014 and December 2016, a total of 233 patients with GB polyps who underwent real-time CDF-EUS were consecutively enrolled in this prospective study. CDF imaging was subjectively categorized for each patient as: strong CDF pattern, weak CDF pattern and no CDF pattern. RESULTS: Of the 233 patients, 115 underwent surgical resection. Of these, there were 90 cases of non-neoplastic GB polyps and 23 cases of neoplastic GB polyps. In a multivariate analysis, a strong CDF pattern was the most significant predictive factor for neoplastic polyps; sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 52.2 %, 79.4 %, 38.7 %, 86.9 % and 73.9 %, respectively. Solitary polyp and polyp size were associated with an increased risk of neoplasm. CONCLUSIONS: The presence of a strong CDF pattern as well as solitary and larger polyps on EUS may be predictive of neoplastic GB polyps. As real-time CDF-EUS poses no danger to the patient and requires no additional equipment, it is likely to become a supplemental tool for the differential diagnosis of GB polyps. KEY POINTS: • Differential diagnosis between neoplastic polyps and non-neoplastic polyps of GB is limited. • The use of real-time CDF-EUS was convenient, with high agreement between operators. • The real-time CDF-EUS is helpful in differential diagnosis of GB polyps.

Clinicopathological characteristics of biliary neuroendocrine neoplasms: a multicenter study.

OBJECTIVES: This study assessed the clinicopathological features, therapeutic approaches, and prognosis of patients with biliary neuroendocrine neoplasm (NENs). MATERIALS AND METHODS: Multicenter retrospective study of patients with biliary tract NENs in the gallbladder, the extrahepatic bile duct, or the ampulla of Vater between 2005 and 2014. RESULTS: Total of 43 patients were included in the study. The median age was 62 years (range: 29-84 years) and 58.1% of the patients were male. The tumors occurred in the gallbladder (n = 11), the extrahepatic bile duct (n = 5) or the ampulla of Vater (n = 27). The liver was the most common metastatic site. Based on the 2010 World Health Organization classification, more patients with gallbladder NENs (11/11 (100%)) had neuroendocrine carcinoma G3 than those with NENs in the ampulla of Vater (10/27 (37.1%)). The median progression free survival time (39.3 vs 5.1 months, p = 0.001) and median overall survival time (46.9 vs 7.9 months, p < 0.001) were significantly longer in patients with ampulla of Vater NENs than gallbladder NENs. A 2010 World Health Organization classification of neuroendocrine carcinoma G3 was independently related to poor overall survival (hazard ratio (HR), 27.1; 95% confidence intervals (CI), 2.81-260.68; p = 0.004). CONCLUSION: The 2010 World Health Organization classification of neuroendocrine carcinoma G3 was the only factor related to poor prognosis in patients with biliary neuroendocrine neoplasms.

Safety and effectiveness of endobiliary radiofrequency ablation according to the different power and target temperature in a swine model.

BACKGROUND AND AIM: Endobiliary radiofrequency ablation (EB-RFA) is a new endoscopic palliation and adjunctive tool. Although EB-RFA is performed worldwide, a possibility of iatrogenic thermal injury leading to perforation or bleeding still remains. Therefore, we aimed to assess the effects of thermal and coagulation injury after in vivo EB-RFA using a new catheter with a temperature sensor in a swine model. METHODS: Twelve mini pigs were divided into four groups according to power (33 mm 10 W electrode vs. 18 mm 7 W electrode) and RFA target temperature (75°C vs. 80°C). All mini pigs underwent endoscopic retrograde cholangiography and target temperature controlled EB-RFA for 120 s. Additional cholangiogram was taken immediately after RFA, and all pigs were sacrificed after 24 h to assess the macroscopic/microscopic RFA injury. RESULTS: Microscopic maximal injury depth and ablation area of EB-RFA using a 33-mm 10 W RFA electrode were significantly deeper and larger than those of EB-RFA using an 18-mm 7 W electrode (median; 2.7 vs. 2.1 mm, P = 0.004, 48.9 vs. 36.2 mm2 , P = 0.016). However, there were no significant differences in microscopic ablation parameters between two different RFA target temperatures (75°C vs. 80°C). In addition, a post-RFA cholangiogram and assessment of the resected specimen at 24 h after the RFA showed no adverse events such as perforation or bleeding. CONCLUSIONS: EB-RFA using a temperature controlled RFA catheter successfully ablates the bile duct wall without adverse events in a swine model.

Diagnostic efficacy of quantitative endoscopic ultrasound elastography for differentiating pancreatic disease.

BACKGROUND AND AIM: Endoscopic ultrasound elastography (EUS-EG) constitutes a novel imaging procedure that allows for the quantification of tissue stiffness with high degrees of accuracy in pancreatic disease. However, the optimal cut-off and reference strain ratio (SR) value of quantitative EUS-EG for differential diagnosis in patients with pancreatic disease remains unclear. This study aimed to clarify these values of normal pancreas, chronic pancreatitis, or pancreatic cancer in an Asian population. METHODS: Between December 2014 and November 2015, 398 patients without pancreatic disease, 67 patients with chronic pancreatitis, and 90 patients with pancreatic cancer who underwent EUS were enrolled prospectively. Elastographic evaluation was measured using the quotient B/A (SR value). RESULTS: The mean SR was 3.78 ± 1.35 for normal pancreas, 8.21 ± 5.16 for chronic pancreatitis, and 21.80 ± 12.23 for pancreatic cancer (P < 0.001). The median SR was 15.14 for mass-forming pancreatitis and 18.00 for pancreatic cancer (P = 0.024). The sensitivity, specificity, and accuracy of the SR were 71.6%, 75.2%, and 74.8%, respectively, for detecting chronic pancreatitis using a cut-off value of 5.62, and were 95.6%, 96.3%, and 96.2%, respectively, for detecting pancreatic cancer using a cut-off value of 8.86. CONCLUSIONS: We provided reference range SR values for normal pancreas, chronic pancreatitis, and pancreatic cancer, as well as an optimal cut-off value for chronic pancreatitis and pancreatic cancer diagnostic accuracy in an Asian population. Quantitative EUS-EG is a supplementary diagnostic method for identifying pancreatic disease.

The short-term efficacy of entecavir in lamivudine-resistant chronic hepatitis B: influence of sequential adefovir-refractoriness.

BACKGROUND/AIMS: Sequential antiviral therapy for chronic hepatitis B may lead to the selection of multidrug-resistant mutation. This study was carried out to assess the efficacy of entecavir in patients that have experienced adefovir monotherapy failure after the development of lamivudine resistance. METHODOLOGY: Fifty-three patients with confirmed genotypic lamivudine-resistant chronic hepatitis B were treated with entecavir. Thirty patients were switched to entecavir directly (LAM-ETV group), whereas the remaining 23 were adefovir-refractory patients who were switched to entecavir (LAM-ADV-ETV group). These 23 patients included 9 patients with inadequate response (ADV-I subgroup) and 14 that exhibited adefovir resistance (ADV-R subgroup). RESULTS: Significantly greater reductions in HBV DNA levels were observed after 24, 48 and 72 weeks of entecavir therapy in the LAM-ETV group than in the LAM-ADV-ETV group, respectively. However, between these two groups at 48 and 72 weeks, no significant differences were observed in cumulative proportions of virological response or breakthrough, respectively. Furthermore, efficacy of entecavir was not significantly different in the ADV-I and ADV-R subgroups. Four patients in the LAM-ETV group and six patients in the LAM-ADV-ETV group developed genotypic resistance to entecavir. CONCLUSIONS: Entecavir therapy is less effective in adefovir-refractory patients with prior lamivudine resistance than in lamivudine-resistant patients.

A randomized controlled trial of pectoralis major myofascial release massage for breastfeeding mothers: breast pain, engorgement, and newborns' breast milk intake and sleeping patterns.

PURPOSE: Supportive interventions to improve breastfeeding practice are needed in nursing. This study investigated the effects of pectoralis major myofascial release massage (MRM) on breast pain and engorgement among breastfeeding mothers and on breast milk intake and sleep patterns among newborns. METHODS: Breastfeeding mothers who had delivered between 37 and 43 weeks and had 7-to 14-dayold newborns were recruited from a postpartum care center in Gunpo, Korea. Participants were randomized to the MRM or control group. The outcome variables were breast pain and breast engorgement among breastfeeding mothers and breast milk intake and sleep time among newborns. The experimental treatment involved applying MRM to separate the pectoralis major muscle and the underlying breast tissue in the chest. After delivery, the first MRM session (MRM I) was provided by a breast specialist nurse, and the second (MRM II) was administered 48 hours after MRM I. RESULTS: Following MRM, breast pain (MRM I: t=-5.38, p<.001; MRM II: t=-10.05, p<.001), breast engorgement (MRM I: right, t=-1.68, p =.100; left, t=-2.13, p=.037 and MRM II: right, t=-4.50, p<.001; left, t=-3.74, p<.001), and newborn breast milk intake (MRM I: t=3.10, p=.003; MRM II: t=3.09, p=.003) differed significantly between the groups. CONCLUSION: MRM effectively reduced breast engorgement and breast pain in breastfeeding mothers, reducing the need for formula supplementation, and increasing newborns' breast milk intake. Therefore, MRM can be utilized as an effective nursing intervention to alleviate discomfort during breastfeeding and to improve the rate of breastfeeding practice (clinical trial number: KCT0002436).