Objective To observe the clinical effect of in situ flap grafting with dentate preservation in the treatment of cricoid mixed hemorrhoids. Methods In a controlled study, 164 patients with cricoid mixed hemorrhoids were randomly divided into 84 patients in the treatment group and 80 patients in the control group, and the treatment group was treated with in situ flap graft dentate preservation surgery, while the control group was treated with traditional external peeling and internal ligation. Results All 164 patients were cured, and the treatment group was better than the control group in terms of healing time, postoperative pain, anal stenosis, and postoperative edema, and the two were statistically significant (P<0.5). Conclusion In situ flap graft dentition preservation is a safe and effective method for the treatment of cricoid mixed hemorrhoids. In order to reduce the pain of patients, shorten the healing time after cricoid mixed hemorrhoid surgery, preserve the anatomy and physiological function of the anus to the maximum extent, and avoid postoperative complications, the clinical data of 164 cases of cricoid mixed hemorrhoids treated by in situ flap graft dentate preservation are reported as follows. 1, Data and methods 1.1, General data: From 2007 to 2011, 164 cases of cricoid mixed hemorrhoids meeting the diagnostic criteria [1] were admitted and randomly divided into 84 cases in the treatment group and 80 cases in the control group according to the order of admission. In the treatment group, there were 48 males and 36 females; the oldest was 72 years old, the youngest was 18 years old, and the average age was 36 years; the longest duration of the disease was 28 years, the shortest was 3.5 years, and the average duration was 8 years; in the control group, there were 44 males and 36 females; the oldest was 70 years old, the youngest was 23 years old, and the average age was 41.5; the longest duration of the disease was 26 years, the shortest was 1.8 years, and the average duration was 10.2 years. The longest disease duration was 26 years, the shortest was 1.8 years, and the average duration was 10.2 years. The two groups of patients were comparable in terms of gender, age and disease duration (P>0.05). 1.2. Treatment methods: routine preoperative preparation, intraoperative sacral anesthesia, bladder amputation position, disinfection, towel spreading, and adequate anal dilation. Treatment group: A shuttle-shaped incision was made at 2 and 4 points, respectively, from the distal end of the external hemorrhoid to the dentate line, and both sides of the incision at 2 and 4 points were subconsciously peeled off to the opposite side, and the varicose vein mass, thrombus and connective tissue were excised at 3 points from the external skin elevation to 0.5 cm above the dentate line, and the normal flap width of the external hemorrhoid was preserved between 0.3-0.5 cm, and the internal part of the hemorrhoid was tied at 0.5 cm above the dentate line with After the ligation, the skin of the external hemorrhoid is kept close to the subcutaneous tissue, the tension is moderate, and the blood flow is kept good, and the skin edge on both sides is trimmed so that the incision is in a natural state. The rest of the mixture was treated in the same way; a longitudinal reduction incision was made at the 6-point incision to sever part of the internal sphincter. Control group: A shuttle-shaped incision was made at 3 points, and the submucosal varicose vein mass, thrombus and connective tissue were peeled off to 0.5 cm above the dentate line, sutured with No. 10 silk thread, and the skin margins on both sides were trimmed so that the incision was in a natural pair and state. The rest of the mixture was treated in the same way; a longitudinal reduction incision was made at the 6-point incision to cut off part of the internal sphincter. Careful intraoperative hemostasis is performed, and excessive skin defects can be intermittently sutured. Absorbable digital hemostatic gauze was applied externally to the incision to stop bleeding, covered with sterile dressing, wrapped with tower gauze, and fixed with pressure by “d” bandage. After the operation, antibiotics were applied for 3 days, and a semi-liquid diet was given for 3 days after the operation to control the bowel movement. 2. Results 2.1. Efficacy criteria and statistical methods Referring to the “Industry Standard of Chinese Medicine of the People’s Republic of China” formulated by the State Administration of Traditional Chinese Medicine in 1994 [1], healed :both symptoms and signs disappeared; significant :symptoms disappeared, leaving the skin or internal hemorrhoid mucosa mildly congested, and the nucleus of hemorrhoid became smaller; effective :both symptoms and signs improved; ineffective :both symptoms and signs did not improve. Observation indexes: postoperative healing time, pain, anal stenosis, edema, etc. The observation results were tested by T-test and X2 test with SPSS10.0 statistical software. 2.2. Comparison of postoperative observation indexes between the treatment group and the control group After treatment, 84 patients in the treatment group and 80 patients in the control group with cricoid mixed hemorrhoids were cured, and the average healing time in the treatment group was (11.86±1.47) days and in the control group was (13.96±1.97) days; t=3.14 by t-test, P=0.004<0.01; 14 patients in the treatment group applied painkillers after surgery, accounting for 16.67%. The postoperative pain relievers were applied to 14 cases in the treatment group (16.67%) and 25 cases in the control group (31.25%); 10 cases of postoperative edema in the treatment group (11.9%) and 18 cases in the control group (22.5%); 3 cases of postoperative anal stenosis in the treatment group (3.75%) and 8 cases in the control group (10%), which were statistically significant compared with the control group (P<0.05). 3. Discussion Circumferential mixed hemorrhoids are a difficult disease to manage in anorectal surgery, and it is a challenge for anorectal surgeons to remove the lesion and relieve the symptoms at one time while preserving the anal shape and function [2]. External stripping and internal ligation and modified procedures [3] [4] have good clinical efficacy, but there are still complications such as postoperative pain, edema, slow wound healing, sensory anal incontinence, mucosal ectasia and anal orifice stenosis. With the progress of society patients' requirements for treatment results have become increasingly prominent in the pursuit of perfection in appearance, in addition to the elimination, improvement or relief of symptoms [5]. Although in situ flap grafting with internal hemorrhoid ligation and dentate reconstruction was applied to treat cricoid mixed hemorrhoids to reduce pain, shorten the treatment course, avoid postoperative complications, and maintain a flat and beautiful anal appearance, we achieved good clinical results, but ligation is sometimes difficult to grasp the site and location of ligation, which affects the postoperative effect [6]. This makes it easier to survive. The in situ flap graft ligation with preserved dentate line is designed based on the theory of hemorrhoid pathogenesis and local anatomy of the anus. The preservation of the dentate line preserves the evoked area of defecation reflex, preserves the local anatomy and physiological function, and causes little damage, does not block the blood and lymphatic circulation, reduces the resting pressure of the anal canal, and effectively prevents postoperative edema; preserving the normal skin width of the external hemorrhoid between 0.3-0.5 cm and making the blood supply rich does not cause ischemic necrosis of the transplanted flap; preserving too wide is easy to form local edema after surgery; preserving too narrow is easy to break the flap after surgery. Too narrow flap is easy to fracture and dissolve necrosis after surgery, forming a larger ulcer surface and larger scar is not easy to heal. Because the wound flaps were relatively natural to each other after treatment, the incision was relatively closed without contact with the outside world, which reduced postoperative pain; because the varicose vascular mass, i.e., the nucleus, was more thoroughly excised, postoperative recurrence was avoided; because the excision area was smaller and a suitable flap was reserved, the wound healed quickly and the anal shape was kept more beautiful, and the average healing time in the treatment group was only 11.86±1.47 days, compared with 13.96±1.97 days in the control group. The average healing time in the treatment group was only 11.86±1.47 days, while that in the control group was 13.96±1.97 days, which was significantly better than that in the control group (P<0.01). Since the lesion in the parent hemorrhoid area was removed, and therefore, with the healing of the incision and the upward movement of the skin after ligation, the formerly elevated external part of the hemorrhoid disappeared. As a result, the anus regained its normal anatomical shape, reducing complications such as postoperative pain, anal stricture, and postoperative edema (P<0.05) and maintaining the aesthetic appearance of the anus. This study addressed the issues of preserving the dentate line, ensuring the survival of the grafted flap, removing the lesion, preserving sufficient skin in the anal region and aesthetic appearance, in accordance with the concept of minimally invasive surgery. Through the clinical study of 164 patients we concluded that in situ flap graft dentate preservation is a simple and effective method for the treatment of cricoid mixed hemorrhoids.