Influencing factors for inadequate bowel preparation of colonoscopy of different colonic segments / 中华消化内镜杂志

Objective:To investigate the influencing factors for inadequate bowel preparation of colonoscopy.Methods:A total of 677 patients who underwent colonoscopy at Peking Union Medical College Hospital from December 2021 to January 2023 were recruited, and all patients underwent standardized bowel preparation by using 3 L polyglycol electrolyte powder with fractional dose. The quality of bowel preparation was assessed by Boston bowel preparation scale, and the influencing factors for inadequate bowel preparation were analyzed by logistic regression analysis.Results:The rate of inadequate bowel preparation was 31.5% (213/677). Among the patients with inadequate bowel preparation, 85.4% (182/213) inadequate bowel preparation was only in proximal colon, 14.1% (30/213) was in both proximal and distal colon, and 0.5% (1/213) was only in distal colon. Inadequate bowel preparation in distal colon and total colon were combined into inadequate bowel preparation in distal colon. The results of logistic regression analysis showed that inadequate bowel preparation in proximal colon was more likely to occur in men ( P=0.001, OR=2.253, 95% CI: 1.399-3.629), outpatients ( P<0.001, OR=4.175, 95% CI: 2.410-7.231), those with no family history of colorectal cancer ( P=0.001, OR=2.117, 95% CI: 1.365-3.284), and diagnostic colonoscopy ( P=0.003, OR=1.978, 95% CI: 1.261-3.102). And spinal disease ( P=0.044, OR=7.430, 95% CI: 1.051-52.511), outpatients ( P<0.001, OR=135.577, 95% CI: 29.135-630.883),non-compliance of dietary requirements ( P=0.006, OR=4.772, 95% CI: 1.576-14.453), adverse reaction during bowel preparation ( P=0.015, OR=4.341, 95% CI: 1.329-14.179), no family history of colorectal cancer ( P=0.003, OR=7.110, 95% CI: 1.912-26.438), and poor last stool character ( P=0.001, OR=25.922, 95% CI: 3.779-177.832) were risk factors for inadequate bowel preparation in distal colon. Conclusions:The inadequate bowel preparation of colonoscopy mainly occurs in proximal colon, and the risk factors for the inadequate bowel preparation vary in different colonic segments. Therefore, the specific interventions should be performed according to the character of different colon segments to improve the quality of bowel preparation.

Effects of Acupuncture Stimulation of Different Layers of "Tianshu" (ST 25) Region on Changes of Intra-colonic Pressure in Normal Rats / 针刺研究

OBJECTIVE: To observe the effect of manual acupuncture stimulation of different layers (skin, muscle, peritoneum, sub-peritoneum) of "Tianshu" (ST 25) region on proximal colonic pressure in normal rats. METHODS: Forty-eight male SD rats were divided into 6 groups: all layer-needling, brushing, cutaneous needling, muscular needling, peritoneum-needling and sub-peritoneum-needling groups (n＝8 in each group). Manual needling or brushing was applied to "Tianshu" (ST 25) region. The colonic internal pressure was measured by using an amplifier and a pressure transducer-connected balloon which was implanted into the colonic cavity about 6 cm from the ileocecal valve. For rats of the all-layer needling group, an acupuncture needle was inserted into ST 25 about 1 cm deep and rotated for a while, for rats of the brushing group, a Chinese calligraphy brush pen was used to brush the skin hair for 1 min. For rats of the rest 4 groups, an acupuncture needle was inserted into the skin, muscle layer after cutting open the skin (about 0.1 cm), the peritoneum layer after cutting open the skin and muscle layers, and the sub-peritoneum layer after cutting open the skin, muscle and peritoneum layers, respectively, and rotated using the uniform reinforcing-reducing technique for about 1 min at a frequency of 120 twirlings per minute every time. RESULTS: During manual needling stimulation of the full layers, cutaneous layer, muscle layer, peritoneum layer and the sub-peritoneum layer of bilateral "Tianshu" (ST 25), the internal pressure of proximal colon was significantly decreased relevant to pre-stimulation in each group (P0.05). During hair brushing of ST 25 region, the colonic pressure was observably increased relevant to pre-needling stimulation (P<0.05). One min after the acupuncture stimulation, the decreased pressures maintained in needling the all-layer on the left side, needling the skin on the right side, needling the peritoneum layer on both sides, and needling the sub-peritoneum layer on both sides relevant to the brushing group of the same side (P<0.05). CONCLUSION: Manual acupuncture stimulation of each layer tissue of ST 25 on both sides may lower internal pressure of proximal colon in normal rats, suggesting their involvement of acupuncture effect in relaxing proximal colonic contraction.

Lymphoglandular complexes in proximal colon of buffalo calves (Bubalus bubalis) / Complejos linfoglandulares en colon proximal de terneros de buffalo (Bubalus bubalis)

The present study was conducted on six healthy early neonatal and six prepubertal buffalo calves to study the location, gross morphology, histomorphology and histochemistry of lymphoglandular complexes in proximal colon. In very proximal part of colon of buffalo calves, an irregular oval mucosal lymphoid patch was found grossly as a proximal colon (PC) patch. Histologically, in proximal colon patch of early neonates (3-4 weeks), an extensive invasion of mucosal glands was observed towards lymphoid nodules that were present in submucosa. The structure as a whole thus formed a complex known as lymphoglandular complex (LGC). Large number of such complexes i.e., LGCs were observed in submucosa of proximal colon at this age. At some places, invasion of mucosal glands into lymphoid tissue was restricted to superficial layer of complexes, with the lymphoglandular complexes opening directly into the lumen but some were deep seated. However, by the age of 6 months in buffalo calves i.e., prepubertal period, LGCs were reduced and were present in single layer within the submucosa of the proximal colon. Moreover, some of LGCs were completely encapsulated by their own lamina muscularis mucosae. But some of the complexes still had their mucosal openings into lumen while others had lost their connection with tunica mucosa. Histochemically, the glands that were observed within LGCs contained mucosubstances, glycogen, mucopolysaccharides, and mucin. However, lipids were present around the lymphocytes observed towards the periphery of these LGCs.

El presente estudio se llevó a cabo en seis terneros de búfalo neonatos sanos y seis terneros prepuberales para estudiar la ubicación, morfología macroscópica, histomorfología e histoquímica de los complejos linfoglandulares en el colon proximal. Se observó en un área del colon proximal (AP) de los terneros de búfalo un óvalo linfoide de mucosa irregular en la parte más proximal de éste. Histológicamente, en el área proximal del colon de los terneros neonatos (3-4 semanas), se observó una invasión extensa de las glándulas mucosas hacia los nódulos linfáticos presentes en la submucosa. La estructura en su totalidad formaba un complejo conocido como complejo linfoglandular (CLG). A esta edad se observó un gran número de estos complejos es decir, se observaron CLGs en la submucosa del colon proximal. La invasión de las glándulas mucosas en el tejido linfoide, se limita a la capa superficial de los complejos, los complejos linfoglandulares distribuidos directamente en el lumen, sin embargo otros se encontraban arraigados de manera profunda. En búfalo a los 6 meses de edad, es decir en el período prepuberal, se observó un número reducido de CLGs presentes en una sola capa dentro de la submucosa del colon proximal. Por otra parte, algunos de CLGs estaban completamente encapsulados por su propia lamina muscularis mucosae. Algunos de los complejos mantenían abertura de las mucosas en el lumen, mientras que otros habían perdido su conexión con la mucosa. En análisis histoquímico, las glándulas que se observaron dentro del CLGs contenían mucosustancias, glucógeno, mucopolisacáridos y mucina. Sin embargo, se encontraron lípidos presentes alrededor de los linfocitos hacia la periferia de los CLGs.

Clinical Outcome of Self-Expandable Metal Stent Placement in the Management of Malignant Proximal Colon Obstruction

BACKGROUND/AIMS: There are limited data regarding the clinical outcomes of self-expandable metal stents in the treatment of proximal colon obstruction. We compared the clinical outcomes of stent placement in patients with malignant proximal to distal colon obstructions. METHODS: We reviewed medical records from 37 consecutive patients from three institutions (19 men; mean age, 72 years) who underwent endoscopic stent placement at a malignant obstruction of the proximal colon. We also examined the records from 99 patients (50 men; mean age, 65 years) who underwent endoscopic stent placement for a distal colon obstruction. Technical success, clinical improvements, complications and stent patency were compared between treatments. RESULTS: The technical success rate tended to be lower in stents inserted to treat proximal colon obstructions than in those used to treat distal colon obstructions (86% vs 97%, p=0.06). Clinical improvement was achieved in 78% of patients (29/37) with proximal colonic stenting and in 91% of patients (90/99) with distal colonic stenting (p=0.08). Complications (24% vs 27%), stent migration (8% vs 8%) and stent reocclusion rates (11% vs 17%) did not differ significantly between groups. Two cases of bowel perforation related to stenting (5%) occurred in patients with proximal colonic stenting. CONCLUSIONS: The technical success and clinical improvement associated with self-expandable metal stents used to treat proximal colon obstruction tend to be lower than cases of distal colon obstruction. Technical failure is an important cause of poor clinical improvement in patients with proximal colon stenting. Complication rates and stent patency appear to be similar in both groups.

The Significance of Synchronous Colorectal Polyps in Colon Cancer Proximal to the Splenic Flexure / 대한소화기내시경학회지

BACKGROUND/AIMS: The aim of this study was to evaluate the characteristics of colorectal polyps, especially distal colorectal polyps and their frequency in patients with colon cancer located proximal to the splenic flexure. METHODS: Among 1,250 patients with colorectal cancer, 269 patients (21.5%) had colon cancer located proximal to the splenic flexure. Of these, 183 patients were involved in this study because complete colonoscopic evaluations to the cecum or to the level of proximal colon cancer were possible. RESULTS: 54 patients (29.5%) had one or more distal colorectal polyps, 33 patients (18.1%) had one or more adenomatous distal polyps, and 3 patients (1.6%) had synchronous distal carcinoma. The percentage of patients without distal polyps was 70.5% of 183 patients with proximal colon cancer, and 80.3% of patients without distal neoplastic lesions. The percentage of patients with advanced lesions (villous component, high-grade dysplasia, or > or =1 cm in diameter) was 40.7% of 54 patients with distal colorectal polyps. CONCLUSIONS: Flexible sigmoidoscopy is insensitive and ineffective for the detection of proximal colon cancer. Ongoing evaluation of colonoscopy as a general screening test is appropriate.