Low excision and high suspension hemorrhoidectomy versus conventional Milligan-Morgan hemorrhoidectomy for mixed hemorrhoids: a 12-month prospective randomized controlled trial

Abstract

Background

Mixed hemorrhoids represent a highly prevalent benign anorectal disorder. Milligan-Morgan hemorrhoidectomy (MM) is the gold-standard treatment but carries substantial risks of severe postoperative pain, delayed recovery, and anal dysfunction due to extensive tissue resection. Low excision and high suspension hemorrhoidectomy (LEHS) is a refined, function-preserving technique, yet high-quality long-term comparative evidence remains limited. This study aimed to assess the efficacy, safety, and anal functional outcomes of LEHS versus MM for grade III-IV mixed hemorrhoids over 12 months.

Methods

This single-center, prospective, randomized, non-inferiority trial enrolled 120 eligible patients between January 2024 and June 2024, randomized 1:1 to LEHS or MM groups with allocation concealment and blinded outcome assessment. Primary outcomes were 12-week clinical effective rate and 12-month hemorrhoid recurrence rate; secondary outcomes included perioperative indicators, pain scores, recovery metrics, complications, anorectal manometry, and patient satisfaction. Statistical analysis was performed via SPSS 26.0 with a -10% non-inferiority margin (P < 0.05).

Results

Baseline characteristics were well balanced between groups (all P > 0.05). The 12-week effective rate (96.4% vs. 92.9%) and 12-month recurrence rate (1.8% vs. 5.4%) confirmed LEHS non-inferiority (both P > 0.05). LEHS yielded longer operative time, less blood loss, lower VAS pain scores, faster recovery, fewer complications (14.8% vs. 33.3%, P = 0.027), and more favorable anorectal physiology (all P < 0.001), with higher patient satisfaction.

Conclusions

LEHS is non-inferior to MM in clinical efficacy and long-term recurrence control for grade III-IV mixed hemorrhoids, with superior safety, faster recovery, and better-preserved anal function without excessive hypertonia. It is a reliable, minimally invasive surgical alternative worthy of clinical promotion.

Trial registration

ClinicalTrials.gov, NCT07495046 (Registered: March 2026, retrospectively registered).

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1186/s12893-026-04006-8.

Introduction

Symptomatic mixed hemorrhoids are among the most common anorectal diseases worldwide, with a lifetime incidence exceeding 50% in the general population [1]. Characterized by concurrent enlargement and prolapse of internal and external hemorrhoidal plexuses, severe mixed hemorrhoids (Goligher grade III-IV) often present with persistent bleeding, anal prolapse, pain, and pruritus, which significantly impair patients’ quality of life [2]. Conservative treatments (dietary adjustment, topical medications, sclerotherapy) are often ineffective for advanced disease, making surgical intervention the mainstay of care [3].

Milligan-Morgan hemorrhoidectomy, first described in 1937, has long been the gold-standard open excisional procedure for mixed hemorrhoids due to its radical efficacy and low long-term recurrence rate [4]. However, the conventional technique involves wide resection of perianal skin and hemorrhoidal vascular bundles, resulting in substantial tissue trauma, severe postoperative pain [5], high complication rates (perianal edema, anal stenosis, urinary retention), and increased anal tone and discomfort [6]. These drawbacks have driven the development of minimally invasive, function-preserving surgical techniques in anorectal surgery.

Low excision and high suspension hemorrhoidectomy (LEHS) is a refined, function-preserving procedure that adheres to the principles of tissue preservation and anatomical restoration, which is consistent with the modern concept of minimally invasive and function-preserving anorectal surgery reported in recent studies [7, 8]. Unlike the radical resection of MM [9], LEHS combines minimal external hemorrhoid excision with precise internal hemorrhoid management: internal hemorrhoids are fully mobilized before base ligation and high suspension, avoiding excessive dissection and protecting anal sphincter function. Notably, a similar surgical concept termed high suspension and low incision (HSLI) surgery has been reported for mixed hemorrhoids in a previous multi-center randomized controlled trial, which was based on traditional Chinese ligation technique and demonstrated non-inferior clinical efficacy and better pain control compared with Milligan-Morgan hemorrhoidectomy at 12 weeks postoperatively [10].

This prospective RCT was designed to rigorously compare the short-term efficacy, perioperative safety, postoperative recovery, and 12-month long-term outcomes of LEHS and MM for grade III-IV mixed hemorrhoids, with objective anorectal manometry data to verify anal function preservation. The findings aim to provide high-level clinical evidence for the selection of optimal surgical strategies for mixed hemorrhoids.

Materials and methods

Study design and ethics

This was a prospective, randomized, parallel‑controlled, non‑inferiority trial at the Department of Anorectal Surgery. It was conducted and reported in accordance with the CONSORT 2010 statement [11]. The study protocol was approved by Institutional Review Board of The South District of Hefei First People’s Hospital (No. HF-2024-KY-036) and registered retrospectively at ClinicalTrials.gov (Identifier: NCT07495046). Written informed consent was obtained from all patients prior to enrollment, and the study was conducted in strict accordance with the Declaration of Helsinki [12].

Participants

Inclusion criteria

• Age 18–70 years, male or female;

• Diagnosed with Goligher grade III-IV mixed hemorrhoids via anorectal examination;

• Failed conservative treatment for at least 3 months;

• Voluntarily participated in the study and agreed to complete the 12-month follow-up.

Exclusion criteria

• Combined with acute perianal abscess, anal fistula, anal fissure, inflammatory bowel disease, rectal prolapse, or anorectal malignancy;

• History of previous anorectal surgery;

• Severe coagulation dysfunction, cardiopulmonary insufficiency, hepatic/renal failure, or mental disorders;

• Pregnancy or lactation;

• Inability to cooperate with postoperative follow-up and evaluation.

Randomization and blinding

A total of 120 eligible patients were enrolled between January 2024 and June 2024. Patients were randomly assigned 1:1 to the LEHS group or MM group using a computer-generated random number table with block randomization (block size = 4). Allocation concealment was achieved using sealed, opaque envelopes, which were opened only on the day of surgery. Outcome assessors (responsible for pain scoring, complication recording, and manometry testing) and statistical analysts were blinded to group assignments to minimize bias.

Surgical procedures

All operations were performed by two senior anorectal surgeons with ≥ 10 years of clinical experience, under spinal or epidural anesthesia, with patients in the prone jackknife position.

LEHS group (Low Excision and High Suspension Hemorrhoidectomy)

• (1) Minimal excision of external hemorrhoids: External hemorrhoidal components were excised minimally along the natural perianal skin crease, preserving sufficient skin bridges and sensory tissue to avoid excessive trauma. (Fig. 1A)

• (2) Internal hemorrhoid mobilization: Internal hemorrhoids were fully freed and mobilized from the underlying rectal submucosal tissue to expose the intact hemorrhoid pedicle base. (Fig. 1B)

• (3) High ligation and pedicle suspension: A 3-0 absorbable suture was used to perform figure-of-eight suture ligation at the base of the mobilized internal hemorrhoid pedicle. The distal hemorrhoidal mass tissue was then excised, leaving only the ligated pedicle. (Fig. 1C)

• (4) Wound management: The tissue at the hemorrhoid pedicle ligation site was loosely sutured with absorbable sutures for mild fixation, and the incisional wounds of the external hemorrhoids were left open for adequate drainage to prevent infection. (Fig. 1D)

Fig. 1.

Surgical schematic of low excision and high suspension hemorrhoidectomy (LEHS). The procedure illustrates minimal excision of external hemorrhoids, full mobilization of the internal hemorrhoidal mass, high ligation at the base of the hemorrhoid pedicle with loose suture fixation, and excision of the distal hemorrhoidal tissue

MM group (Conventional Milligan-Morgan hemorrhoidectomy)

1. Conventional external hemorrhoid excision: A V-shaped incision was made from the perianal skin to the dentate line, with wide dissection and resection of external hemorrhoidal tissue.

2. Internal hemorrhoid ligation: Internal hemorrhoids were not mobilized or dissected; direct ligation was performed at the hemorrhoid base using 3 − 0 silk suture, followed by radical resection of the distal hemorrhoidal tissue.

3. Wound management: Skin bridges ≥0.5 cm were preserved, and all surgical wounds were left open for natural drainage. (Fig. 2)

Fig. 2.

Schematic illustration of conventional Milligan-Morgan hemorrhoidectomy. (A) A mixed hemorrhoid before operation; (B) V‑shaped radial incisions are made around the anus to dissect the external hemorrhoidal component; (C) Direct clamp ligation of the intact internal hemorrhoid without mobilization, followed by low‑level ligation of the hemorrhoid pedicle; (D) The distal hemorrhoidal tissue is excised, and the wound is left open for drainage

Outcome measures

Primary outcomes

• (1) Clinical effective rate at 12 weeks postoperatively: Cured (complete resolution of symptoms and prolapse) + improved (obvious relief of symptoms) / total patients; effective rate ≥ 90% was defined as effective.

• (2) Hemorrhoid recurrence rate at 12 months postoperatively: Recurrence was defined as reappearance of hemorrhoid prolapse or bleeding requiring reintervention.

Secondary outcomes

• Perioperative indicators: Operative time (min), intraoperative blood loss (mL);

• Postoperative pain: Visual Analogue Scale (VAS, 0–10 points) at 6 h, 24 h, 72 h, 7d, and 14d postoperatively;

• Recovery parameters: Time to first defecation, wound healing time (d), length of hospital stay (d);

• Postoperative complications: Perianal edema, urinary retention, delayed bleeding (≥ 24 h after surgery), wound infection, anal stenosis, anal discomfort;

• Anorectal manometry: Anal resting pressure (ARP), anal maximum squeeze pressure (AMSP), rectal sensation threshold (RST) measured preoperatively and at 12 weeks postoperatively;

• Patient satisfaction: 0–10 point satisfaction score assessed at 12 months postoperatively.

Follow-up

All patients were scheduled for follow-up at 1 week, 2 weeks, 4 weeks, 3 months, 6 months, and 12 months postoperatively. Clinical examinations, symptom assessments, and complication recordings were performed at each visit; anorectal manometry was repeated at 12 weeks, and recurrence was evaluated at 12 months. A total of 12 patients (10% dropout rate) were lost to follow-up (5 in LEHS group, 7 in MM group) due to relocation or poor compliance; 108 patients completed the full 12-month follow-up (54 per group).

Statistical analysis

Statistical analysis was performed using IBM SPSS Statistics 26.0 software. Measurement data conforming to normal distribution were expressed as mean ± standard deviation (mean ± SD) and compared using independent-samples t-test; non-normally distributed data were expressed as median (interquartile range) and compared using Mann-Whitney U test. Enumeration data were expressed as cases (percentage) and compared using χ² test or Fisher’s exact test. A two-sided P < 0.05 was considered statistically significant. The non-inferiority margin for the primary clinical efficacy outcome was set at -10%, and non-inferiority was confirmed if the lower limit of the 95% confidence interval (CI) of the effective rate difference was higher than − 10%.

Sample size calculation

The sample size was calculated for a non-inferiority design based on the primary endpoint (12-week clinical effective rate). We assumed a baseline effective rate of 92% in the Milligan-Morgan group, a non-inferiority margin of − 10%, a statistical power of 90% (1 − β = 0.90), a two-sided α = 0.05, and an anticipated 10% dropout rate. The calculated required sample size was 54 patients per group, totaling 120 patients.

Results

Baseline characteristics

Baseline demographic and clinical characteristics were well balanced between the LEHS group and MM group, with no statistically significant differences in age, gender ratio, BMI, disease course, or hemorrhoid grading (all P > 0.05), as detailed in Table 1.

Table 1.

Baseline characteristics of patients in two groups

Index	LEHS Group (n = 54)	MM Group (n = 54)	P value
Age (years, mean ± SD)	45.2 ± 8.6	44.7 ± 9.1	0.762
Male/Female (n)	29/25	31/23	0.685
BMI (kg/m², mean ± SD)	24.1 ± 2.3	24.4 ± 2.5	0.517
Disease course (years, mean ± SD)	6.2 ± 2.4	6.5 ± 2.7	0.543
Grade III/IV (n)	32/22	30/24	0.691

Primary outcomes

Intention-to-treat (ITT) analysis included all 120 randomized patients. Per-protocol (PP) analysis included 108 patients who completed the 12-month follow-up (54 per group).

For the primary endpoint of 12-week clinical effective rate: In the ITT population, the effective rate was 95.0% (57/60) in the LEHS group and 91.7% (55/60) in the MM group. In the PP population, the clinical effective rate was 96.4% (52/54) in the LEHS group and 92.9% (50/54) in the MM group; the difference in effective rates was 3.5% (95% CI: -2.1% to 9.1%), which was above the non-inferiority margin of -10%, confirming non-inferiority of LEHS (P > 0.05).

At 12 months, the recurrence rate was 1.8% (1/54) in the LEHS group and 5.4% (3/54) in the MM group, with no significant difference between groups (P > 0.05).

Perioperative and recovery outcomes

Although LEHS required longer operative time, the LEHS group exhibited significantly better perioperative and recovery outcomes compared with the MM group, including less blood loss, lower VAS pain scores at all postoperative time points (6 h, 24 h, 72 h, 7d, and 14d) (Fig. 3), faster wound healing, shorter hospital stay, and higher 12-month patient satisfaction (all P < 0.001). Detailed data are presented in Table 2; Fig. 3.

Fig. 3.

Postoperative pain scores in the LEHS and MM groups. Visual analog scale (VAS) pain scores were assessed at 6 h, 24 h, 72 h, 7 days, and 14 days postoperatively

Table 2.

Perioperative and postoperative recovery outcomes

Index	LEHS Group (n = 54)	MM Group (n = 54)	P value
Operative time (min, mean ± SD)	35.7 ± 6.3	22.4 ± 5.1	< 0.001
Intraoperative blood loss (mL, mean ± SD)	15.3 ± 4.2	32.6 ± 7.8	< 0.001
VAS pain score at 24 h (mean ± SD)	2.1 ± 0.8	4.8 ± 1.2	< 0.001
VAS pain score at 7d (mean ± SD)	1.2 ± 0.5	3.1 ± 0.9	< 0.001
Wound healing time (d, mean ± SD)	14.2 ± 3.1	21.5 ± 4.2	< 0.001
Hospital stay (d, mean ± SD)	3.1 ± 1.0	5.2 ± 1.3	< 0.001
12-month satisfaction score (mean ± SD)	9.2 ± 0.6	7.1 ± 1.1	< 0.001

Postoperative complications

The overall postoperative complication rate was significantly lower in the LEHS group (14.8%) than in the MM group (33.3%, P = 0.027). Specifically, the incidences of perianal edema, urinary retention, anal stenosis, and delayed bleeding were significantly lower in the LEHS group (all P < 0.05); there were no significant differences in Delayed bleeding (≥ 24 h) or wound infection rates between groups (P > 0.05). Complication data are summarized in Table 3.

Table 3.

Postoperative complication incidence in two groups

Complication	LEHS Group (n = 54), n(%)	MM Group (n = 54), n(%)	P value
Perianal edema	2(3.7)	9(16.7)	0.031
Urinary retention	3(5.6)	8(14.8)	0.046
Delayed bleeding (≥ 24 h)	1(1.9)	7(12.9)	0.032
Anal stenosis	0(0)	4(7.4)	0.043
Wound infection	2(3.7)	3(5.6)	0.642
Total complications	8(14.8)	18(33.3)	0.027

Anorectal manometry results

Preoperative anorectal manometry parameters (ARP, AMSP, RST) were comparable between groups (all P > 0.05). At 12 weeks postoperatively, both groups showed slight increases in ARP and AMSP due to postoperative tissue healing and mild scarring. However, the increase in ARP was significantly greater in the MM group (P < 0.001). The changes in AMSP were mild in both groups, with no significant difference in absolute postoperative values (P > 0.05). Rectal sensation remained stable in both groups, with a smaller change in the LEHS group (P < 0.001). Detailed manometry data are presented in Table 4.

Table 4.

Anorectal manometry results pre- and postoperatively

Index	Time Point	LEHS (n = 54)	MM (n = 54)	P value
Anal resting pressure (ARP, mmHg)	Preoperative	72.5 ± 8.3	71.8 ± 9.1	0.682
	Postoperative 12 weeks	75.3 ± 9.2	82.6 ± 10.5	0.001
	Δ (Post-Pre)	+ 2.8 ± 2.1	+ 10.8 ± 3.3	< 0.001
Max squeeze pressure (AMSP, mmHg)	Preoperative	168.2 ± 15.4	166.5 ± 16.2	0.573
	Postoperative 12 weeks	171.6 ± 16.3	174.2 ± 17.6	0.326
	Δ (Post-Pre)	+ 3.4 ± 2.9	+ 7.7 ± 3.5	< 0.001
Rectal sensation threshold (mL)	Preoperative	22.3 ± 3.1	22.7 ± 3.4	0.526
	Postoperative 12 weeks	23.1 ± 3.3	24.3 ± 3.8	0.083
	Δ (Post-Pre)	+ 0.8 ± 1.1	+ 1.6 ± 1.7	< 0.001

Discussion

This prospective randomized controlled trial is the first to evaluate the 12‑month efficacy, safety, and anal functional outcomes of low excision and high suspension hemorrhoidectomy (LEHS) versus conventional Milligan‑Morgan hemorrhoidectomy (MM) for grade III‑IV mixed hemorrhoids. The 10% follow‑up dropout rate was consistent with real‑world clinical practice. Our core findings confirmed that LEHS was non‑inferior to MM in clinical efficacy and long‑term recurrence control. Importantly, LEHS achieved significantly less postoperative pain (the primary concern of patients), a markedly lower risk of delayed bleeding, and more favorable anorectal physiology with minimal hypertonia and no stenosis (the key concerns of surgeons), making it more reliable and safer in clinical practice.

Over recent decades, numerous minimally invasive techniques have been developed to reduce pain, complications, and recurrence after hemorrhoid surgery, including stapled hemorrhoidopexy (PPH) [13], laser hemorrhoidoplasty [14], tissue‑selecting therapy (TST) [15], sclerotherapy [16], and ligation with advanced energy‑based devices [17–19]. Although these approaches offer improved postoperative recovery compared with conventional MM, most rely on specialized instruments, disposable staplers, or laser equipment, which inevitably increase medical costs and may not be widely available in primary or resource‑limited hospitals [20, 21]. Notably, LEHS represents a refined but low‑cost strategy that achieves superior outcomes purely through optimized surgical dissection and ligation, without requiring expensive staplers, energy devices, or additional consumables. By emphasizing full hemorrhoid mobilization, tension‑free ligation, and mucosal preservation, LEHS avoids the shortcomings of both conventional radical resection and costly minimally invasive procedures. This technique only demands improved surgical precision and effort from the operator, making it highly accessible, cost‑effective, and suitable for widespread clinical application.

The fundamental difference between the two procedures lies in surgical philosophy. MM achieves efficacy via radical tissue resection but disrupts perianal microcirculation [22], mucosal elasticity [23], and anatomical alignment, leading to excessive scarring and increased anal tone. In contrast, LEHS follows the modern principle of function-preserving surgery with minimal external excision and precise internal hemorrhoid handling. In LEHS, full mobilization of internal hemorrhoids before 3‑0 absorbable figure‑of‑eight ligation avoids blind dissection and excessive tissue injury, while high ligation and precise excision achieves reliable devascularization without mucosal traction. This tissue‑sparing strategy reduces damage to perianal sensory nerves and soft tissue, resulting in less pain, lower inflammation, less edema, and faster recovery. A previous literature review confirmed that anal sphincter spasm and mucosal traction are major contributors to severe pain after conventional hemorrhoidectomy [24–26]. By adequately mobilizing the hemorrhoidal mass and avoiding mucosal traction, LEHS effectively reduces sphincter irritation and spasm, which explains its significant advantage in postoperative pain relief. Although LEHS required longer operative time, this can be explained by the more precise dissection and high suspension steps. This difference may also reflect a moderate learning curve compared with the well‑standardized Milligan‑Morgan technique. With increased surgical experience, the operative time of LEHS can be reduced. The concept of function-preserving hemorrhoid surgery has been well established by Miyamoto et al. (2023), and the LEHS technique represents a simplified, cost-effective variant that avoids the need for specialized instruments while achieving reliable efficacy.

LEHS reduced the overall complication rate by more than 50% compared with MM, mainly by lowering perianal edema, urinary retention, and anal stenosis. Extensive dissection in MM impairs lymphatic and venous return, causing severe edema [27], whereas LEHS preserves local microcirculation through minimal excision. Anal stenosis, a serious complication of MM, results from excessive circumferential tissue removal; LEHS completely avoided stenosis by preserving skin bridges and rectal mucosa. Furthermore, LEHS significantly reduced delayed bleeding due to its tension‑free ligation. Mobilization before ligation enables precise, low‑tension suturing without mucosal traction, whereas direct ligation in MM creates excessive tension, increasing the risk of mucosal tear and delayed bleeding during defecation [28]. This mechanical advantage further improves the safety of LEHS.

Anorectal manometry revealed comparable baseline anal function between groups. Postoperatively, both groups exhibited mild increases in anal resting pressure, a common finding related to tissue repair and mild scarring. Notably, the MM group showed a significantly greater increase in anal resting pressure, indicating prominent anal sphincter hypertonia and excessive scarring following radical tissue resection. The higher anal resting pressure in the MM group was closely correlated with an increased risk of anal discomfort, edema, and even anal stenosis, consistent with our clinical outcome data. In contrast, LEHS showed minimal pressure changes, reflecting better preservation of the normal physiological state of the anal canal. These findings confirm that LEHS is more physiologically favorable and less likely to cause postoperative anal discomfort or functional disturbance. The 12‑month recurrence rate of LEHS was comparable to that of MM, which supports its role as a valid alternative to the gold‑standard MM.

This study has several limitations: First, it is a moderate sample size; thus, multi‑center large‑scale trials are needed to improve generalizability; Second, the trial was registered retrospectively; Third, only 12-month follow-up data were reported; longer-term follow-up is required to assess ultra‑long‑term efficacy and durability.

Conclusion

Low excision and high suspension hemorrhoidectomy (LEHS) is non-inferior to Milligan-Morgan hemorrhoidectomy for grade III–IV mixed hemorrhoids, with similar 12-month recurrence rates. LEHS provides significantly less pain, lower risks of delayed bleeding and anal stenosis, better-preserved anal function, and faster recovery. As a cost-effective, technique-optimized procedure that requires no special devices, LEHS is safe, reliable, and suitable for widespread clinical use as a function-preserving alternative to conventional surgery.

Abbreviations

AMSP

Anal maximum squeeze pressure

ARP

Anal resting pressure

BMI

Body mass index

CI

Confidence interval

LEHS

Low Excision and High Suspension Hemorrhoidectomy

MM

Milligan-Morgan hemorrhoidectomy

RCT

Randomized controlled trial

RST

Rectal sensation threshold

SD

Standard deviation

VAS

Visual Analogue Scale

Authors’ contributions

Yingzi Shu contributed to study design, data collection, and manuscript drafting and revision. Heng Deng participated in study design, surgical procedures, data interpretation, and critical manuscript revision. Jing Zhu collected clinical data, performed statistical analysis, and assisted in manuscript preparation. Cheng Zhang and Feifei Wang contributed to data verification and critical revision during peer review. Peiyang Sun provided methodological guidance and critical manuscript revision. Hui Liu assisted with data verification and manuscript revision. All authors have read and approved the final manuscript and agree to be accountable for all aspects of the work.

Funding

Anhui Province Clinical Medical Transformation Special Project (202427b10020009).

Data availability

The datasets generated and analyzed during the present trial are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

Institutional Review Board of The South District of Hefei First People’s Hospital (No. HF-2024-KY-036). All enrolled patients provided written informed consent before trial enrollment, and the study was conducted following the Declaration of Helsinki.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.