The application of intraoperative strategies to reduce protective stoma in mid and low rectal cancer: a retrospective study utilizing indocyanine green and precise anatomical techniques

Abstract

Background

Mid and low rectal cancer is among the most prevalent malignancies worldwide. Total mesorectal excision (TME) remains the standard surgical approach for these cancers. However, anastomotic leakage (AL) represents a significant complication associated with laparoscopic total mesorectal excision (LaTME) in cases of mid-low rectal cancer, often necessitating the creation of a protective stoma. This study evaluates the "PHISTA Technique," a novel protocol that integrates perfusion assessment, splenic flexure mobilization, vascular optimization, and reinforced anastomosis, with the aim of reducing stoma rates while maintaining safety standards.

Methods

Patients diagnosed with mid and low rectal cancer between December 2022 and December 2024 were retrospectively included and categorized into the conventional LaTME group and the PHISTA Technique group. The basic characteristics and short-term outcomes of the two groups were compared.

Results

The protective stoma rate was 0% in the PHISTA group vs. 31.7% in the conventional LaTME group (P < 0.001). The AL rate was 5.7% (PHISTA) vs. 6.7% (conventional LaTME) (P > 0.05). There were no significant differences in operative time, blood loss, lymph node yield, or postoperative recovery indicators between the groups.

Conclusion

The PHISTA Technique was associated with a significantly reduced rate of protective stoma without increasing the incidence of anastomotic leakage. This approach has the potential to reduce or eliminate the need for a subsequent stoma reversal surgery in a substantial proportion of patients, thereby potentially reducing patient suffering and economic burden.

Introduction

Mid and low rectal cancer is one of the most prevalent cancers globally, with both incidence and mortality rates ranking prominently [1, 2]. With shifts in lifestyle patterns and an aging population, the incidence of rectal cancer has increased in many countries, presenting a significant challenge to public health [3].

The current standard surgical approach for mid and low rectal cancer is LaTME. LaTME effectively removes rectal cancer while preserving surrounding tissues; however, it has certain limitations in treating mid and low rectal cancers, particularly due to a relatively high risk of postoperative anastomotic leakage [4]. To mitigate this risk, conventional LaTME is frequently performed in conjunction with a protective stoma. However, the implementation of a protective stoma not only necessitates a subsequent surgical procedure (stoma reversal) for closure, which exposes the patient to additional surgical trauma and recovery time, but also imposes significant economic burdens. Therefore, minimizing the need for protective stomas without increasing the rate of anastomotic leakage has become a critical focus in improving surgical techniques for rectal cancer [5]. Recent advancements in medical technology have facilitated the gradual adoption of various surgical techniques in rectal cancer surgery. This has resulted in the development of combined strategies designed to address the limitations of conventional LaTME and reduce the incidence of anastomotic leakage [6]. The comprehensive application of these multiple technologies includes:1.ICG tracing navigation [7, 8, 9, 10]; 2. Adequate mobilization of the splenic flexure [11, 12]; 3. Preservation of the left colic artery with high ligation of the inferior mesenteric vein and dissection of No. 253 lymph nodes [13, 14, 15]; 4. Conventional LaTME technique [16]; 5. ICG-guided assessment of blood supply before and after anastomosis [17]. 6. Enhanced anastomotic suturing using barbed sutures [18, 19]. We have innovatively designated this surgical strategy, which integrates the aforementioned techniques, as the "PHISTA Technique" derived from the initial letters of each respective method.

Although the theoretical application of PHISTA Technique shows promise in reducing anastomotic leakage, there is a significant lack of systematic evidence regarding its effectiveness and safety in clinical practice. This includes uncertainty regarding whether it can further reduce the incidence of anastomotic leakage in the absence of a protective stoma. Therefore, this study aims to assess the impact of PHISTA Technique on postoperative anastomotic leakage rates in patients with mid and low rectal cancer through retrospective data analysis, thus providing a reliable reference for clinical practice.

Materials and methods

Patients

A total of 95 patients diagnosed with mid and low rectal cancer were consecutively enrolled at Northern Jiangsu People's Hospital in Jiangsu Province from December 2022 to December 2024. The inclusion criteria for this study were as follows: 1. Age between 18 and 80 years; 2. Diagnosis of rectal adenocarcinoma confirmed by electronic colonoscopy and pathology, with the lower edge of the tumor located within 10 cm from the anal verge, as measured by rigid proctoscopy or MRI; 3. First-time surgical intervention; 4. Laparoscopic surgery; 5. Availability of complete clinical and pathological data, along with follow-up information; 6. Absence of severe cardiovascular or metabolic diseases; 7. No evidence of distant metastasis prior to surgery and no administration of neoadjuvant chemoradiotherapy; 8. Informed consent obtained from the patient or their authorized representative. The exclusion criteria were: 1. Preoperative neoadjuvant therapy or perioperative radiotherapy; 2. History of other malignant tumors; 3. Emergency surgery required due to obstruction, perforation, or bleeding; 4. Severe mental illness; 5. Pregnant or lactating women.

All surgical procedures were conducted by the same surgical team to ensure consistency in technique and approach. After being fully informed of the advantages and disadvantages associated with both the PHISTA Technique and conventional LaTME surgery, patients were given the autonomy to freely choose their preferred surgical method. Patient counseling, while structured to present a balanced view of both approaches, was not guided by a formalized decision aid or script, which represents a potential source of bias. Informed consent was obtained from all participants involved in this study, which was approved by the Ethics Committee of Northern Jiangsu People's Hospital in Jiangsu Province (No. 2024ky343).

Data collection

Data for this analysis were derived from a prospectively maintained colorectal surgery database at our institution. Patient characteristics, perioperative data, and follow-up information were systematically recorded into this database at the time of treatment and discharge. The basic characteristics collected included gender, age, body mass index (BMI), preoperative hemoglobin levels, maximum tumor diameter, distance from the lower edge of the tumor to the anal verge, degree of tumor differentiation, and the American Joint Committee on Cancer (AJCC) stage, the latter serving as an indicator of pathological progression. Perioperative data included operation time, length of hospital stay, time to first postoperative flatus, time to first postoperative defecation, intraoperative blood loss, total number of lymph nodes dissected, use of intraoperative protective stoma, incidence of postoperative anastomotic leakage, and relevant pathological data, which were obtained from surgical records and pathological reports. The primary outcome was the incidence of postoperative anastomotic leakage. Anastomotic leakage was defined and graded according to the criteria established by the International Study Group of Rectal Cancer (ISREC) into Grade A (requiring no active therapeutic intervention), Grade B (requiring active therapeutic intervention but not re-laparotomy), and Grade C (requiring re-laparotomy). The secondary outcome was the occurrence of postoperative complications.

Surgical approaches Statistical analysis

All procedures were performed laparoscopically with the patient in the lithotomy position under general anesthesia. Pneumoperitoneum was established and standard port placements were utilized.

Laparoscopic total mesorectal excision(LaTME)

The procedure was performed following standard principles of total mesorectal excision.

If anastomotic tension was anticipated, partial mobilization of the splenic flexure was performed at the operating surgeon's discretion to ensure a tension-free anastomosis. Anastomosis was performed using a circular stapler.

PHISTA Technique

This integrated approach included the following key steps: (1) Fluorescence-guided navigation with indocyanine green (ICG) injected peri-tumorally (Fig. 1A-1C); (2) Complete mobilization of the splenic flexure (Fig. 1D-F); (3) Low ligation of the IMA with preservation of the left colic artery, coupled with high ligation of the IMV and dissection of No. 253 lymph nodes (Fig. 1G-I, Fig. 2A-C); (4) LaTME according to standard principles; (5) Intravenous ICG fluorescence angiography to assess anastomotic perfusion prior to reconstruction (Fig. 2D-F); (6) Reinforcement of the anastomosis with a barbed suture. The anastomosis was created using a circular stapler (Fig. 2G-I).

Fig. 1.

A Indocyanine green (ICG) solution was injected into the serosal layer 1 cm from the tumor margin; B Fluorescence mode; C Visualization of lymph nodes; D, E, F Mobilization of the splenic flexure; G, H, I The left colic artery was preserved under fluorescence-guided laparoscopic imaging, and No. 253 lymph nodes, including those along the mesenteric artery and retroperitoneal lymph nodes, were excised

Fig. 2.

A, B, C The inferior mesenteric vein was ligated at a high level; D, E, F Prior to anastomosis, ICG was injected intravenously to assess bowel perfusion; G, H, I Reinforcement of the anastomosis with barbed suture under laparoscopic guidance

Criteria for protective stoma

The decision to create a protective stoma was not made arbitrarily but was guided by a combination of intraoperative assessments aimed at evaluating the risk of anastomotic leakage. In both groups, the decision was primarily based on the following objective criteria:

• 1.Anastomotic Perfusion: Compromised blood flow at the proximal colon limb or the anastomotic doughnuts, as assessed subjectively by serosal color and capillary bleeding, and objectively using indocyanine green (ICG) fluorescence angiography. A poorly perfused anastomosis was a strong indication for a stoma.

• 2.Anastomotic Tension: Excessive tension on the anastomosis, assessed by the inability to bring the colon down to the pelvic rim without traction, or visible stretching of the mesentery.

• 3.Anastomotic Integrity and Technical Quality: Any technical defect noted during the stapling or reinforced suturing process, such as staple line disruption or air leak tested intraoperatively.

• 4.Patient-Related Risk Factors: The presence of major comorbidities that are known to impair healing. For this study, major comorbidities were specifically defined to include uncontrolled diabetes (preoperative HbA1c > 7.5% or random blood glucose persistently ≥ 10 mmol/L), severe malnutrition (preoperative serum albumin < 30 g/L).

In the PHISTA group, the integrated techniques were specifically applied to optimize the conditions for a safe primary anastomosis without a stoma. The preservation of the left colic artery and high ligation of the IMV were aimed at maximizing blood supply and achieving sufficient length, thereby directly addressing criteria 1 and 2. The routine use of ICG angiography provided an objective measure to confirm adequate perfusion. Therefore, the significantly lower stoma rate in the PHISTA group is a direct result of the technique successfully achieving its goal of creating a well-perfused, tension-free anastomosis that met the safety criteria for omission of a protective stoma. In the conventional LaTME group, the decision was made more frequently due to unaddressed tension or concerns about blood supply.

Statistical analysis

Data analysis was conducted using SPSS 26.0 (SPSS, Chicago, Illinois, USA). Categorical data are presented as percentages (%). Fisher's exact test or χ2 test was employed to assess the accuracy of comparative analysis. Normally distributed continuous variables were analyzed using the t-test and are presented as mean ± standard deviation (mean ± SD). Non-normally distributed continuous variables were analyzed using non-parametric tests and are presented as median (interquartile range). A P-value of < 0.05 was considered statistically significant.

Results

A total of 95 patients were ultimately included in the study, among which 35 were in the PHISTA Technique group and 60 in the conventional LaTME group. The follow-up results of the patients were recorded until discharge.

Basic characteristics of patients

A total of 95 patients were enrolled in this study, with 35 in the PHISTA Technique group and 60 in the conventional LaTME group. All patients had mid or low rectal cancer, defined as a tumor with its lower edge situated within 10 cm of the anal verge. No significant differences were observed in baseline characteristics between the two groups (Table 1).

Table 1.

Basic characteristics of patients

Characteristics	PHISTA (n = 35)	Conventional LaTME (n = 60)	X2/t/Z	P
Sex, n (%)			X2 = 0.794	0.373
Male	22(62.9)	43(71.7)
Female	13(37.1)	17(28.3)
Age (years), mean (SD)	65.06 ± 11.84	66.03 ± 10.78	t = −0.410	0.682
BMI (kg/m2), median (IQR)	22.49(21.19,24.44)	23.32(21.34,25.44)	Z = −1.300	0.194
Preoperative hemoglobin, n (%)			X2 = 0.145	0.703
< 120 g/L	10(28.6)	15(25.0)
≥ 120 g/L	25(71.4)	45(75.0)
The maximal diameter of the tumor (cm), mean (SD)	4.11 ± 1.44	3.80 ± 1.11	t = 1.187	0.238
The distance from the inferior margin of the tumor to the anal verge, median (IQR)	10.00(8.00,12.00)	8.00(5.00,10.00)	Z = −0.702	0.482
AJCC stage, n (%)			X2 = 0.008	0.928
I-II	19(54.3)	32(53.3)
III-IV	16(45.7)	28(46.7)
Tumor differentiation, n (%)			X2 = 1.733	0.368
Well and moderate	1(2.9)	0(0)
Poor	34(97.1)	60(100.0)
Glucose metabolism status, n (%) a			X2 = 0.314	0.855
No diabetes	25 (71.4)	40 (66.7)
Diabetes, well-controlled	7 (20.0)	15 (25.0)
Diabetes, poorly-controlled	3 (8.6)	5 (8.3)
Preoperative serum albumin, n (%)b			X2 = 0.172	0.918
Normal (≥ 35 g/L)	28 (80.0)	50 (83.3)
Mild reduction (30–34.9 g/L)	5 (14.3)	7 (11.7)
Severe reduction (< 30 g/L)	2 (5.7)	3 (5.0)

^*Footnote: 1.The high proportion of poorly differentiated adenocarcinoma in our cohort may be explained by: (1) our center’s role as a regional referral hospital, leading to a case mix skewed toward advanced/aggressive disease; (2) our institutional pathological practice of classifying tumors with any significant poorly differentiated component as “poorly differentiated”; and (3) the selective nature of this study cohort (mid-low rectal cancer, no neoadjuvant therapy). This distribution may limit direct extrapolation to populations with different histological profiles.*

2.a:Well-controlled: preoperative HbA1c ≤ 7.5% or random blood glucose < 10 mmol/L; Poorly-controlled: preoperative HbA1c > 7.5% or random blood glucose ≥ 10 mmol/L.*

b: Severe hypoalbuminemia (< 30 g/L) was considered a major comorbidity potentially affecting healing.*

Perioperative outcomes

Although not a pre-specified primary outcome, the rate of protective stoma formation was markedly different between the two groups. The protective stoma rate in the PHISTA Technique group was 0%, significantly lower than that in the conventional LaTME group (31.7%, P < 0.001). It should be noted that this represents a key secondary finding, as the primary outcome was anastomotic leakage. The anastomotic leakage rate in the PHISTA Technique group was 5.7%, compared to 6.7% in the conventional LaTME group. The anastomotic leakage rate in the PHISTA Technique group was slightly lower than that in the conventional LaTME group; however, no significant difference was found between the two groups (P > 0.05). Specifically, when stratified by severity using the ISREC classification, in the PHISTA group, one case of leakage was classified as grade A (conservative treatment), and one case was classified as grade B (requiring radiological guided drainage). No statistically significant differences were observed between the PHISTA Technique group and the conventional LaTME group regarding intraoperative indicators (e.g., operation time, intraoperative blood loss, and number of lymph nodes dissected) (P values: 0.116, 0.268, and 0.066, respectively). No statistically significant differences were observed between the PHISTA Technique group and the conventional LaTME group in terms of postoperative recovery indicators (e.g., time to first postoperative flatus, time to first postoperative defecation, and length of hospital stay) (P values: 0.409 and 0.342, respectively). The operation time in the PHISTA Technique group was slightly longer than in the conventional LaTME group; however, no statistically significant difference was found between the two groups (median time: 145 min vs. 132 min, P = 0.440) (Tables 2 and 3).

Table 2.

Perioperative outcomes

Characteristics	PHISTA (n = 35)	Conventional LaTME (n = 60)	X2/t/Z	P
Operation time (min), median (IQR)	145.00(110.00,175.00)	132.(110.00,155.00)	Z = −0.773	0.440
Postoperative hospitalization (d), median (IQR)	13.04(11.03,15.71)	11.96(10.03,14.57)	Z = −1.836	0.066
Time to first gas passing (d), median (IQR)	4.00(3.00,5.00)	3.00(3.00,4.00)	Z = −1.573	0.116
Time to first stool passing (d), median (IQR)	5.00(4.00,6.00)	5.00(3.25,6.00)	Z = −1.107	0.268
Estimated blood loss (ml), median (IQR)	50.00(20.00,50.00)	50.00(20.00,50.00)	Z = −0.825	0.409
Number of lymph nodes dissected, mean (SD)	14.60 ± 6.98	13.37 ± 5.08	t = 0.992	0.324
Number of preventive stomas, n (%)	0(0)	19(31.7)	X2 = 13.854	< 0.001
Number of anastomotic leaks, n (%)	2(5.7)	4(6.7)	X2 = 0.034	1.000
CRM positive, n (%)	1 (2.9)	2 (3.3)	X2 = 0.026	0.872
DRM positive, n (%)	0 (0)	1 (1.7)	X2 = 0.53	0.466
Complete TME, n (%)	34 (97.1)	58 (96.7)	X2 = 0.026	0.872

Table 3.

Severity of Anastomotic Leakage According to ISREC Classification

Group	Total Patients	Any Leak, n (%)	Grade A, n	Grade B, n	Grade C, n
PHISTA	35	2 (5.7)	1	1	0
conventional LaTME	60	4 (6.7)	1	2	1

Discussion

This study assessed the treatment outcomes of the PHISTA Technique—a composite of various surgical approaches for rectal cancer resection—in the context of mid and low rectal cancer, a subject that has been scarcely explored in the literature. A total of 95 patients were included in a retrospective, comprehensive analysis to evaluate the feasibility, safety, and efficacy of the PHISTA Technique. This retrospective study primarily aimed to assess the safety of the PHISTA Technique, with a pre-specified focus on the incidence of anastomotic leakage as the primary outcome. The central and most significant finding, however, was the dramatic reduction in the rate of protective stoma in the PHISTA group (0% vs. 31.7%), which, although not the primary endpoint, carries substantial clinical implications. Concurrently, the technique demonstrated non-inferiority in terms of anastomotic leakage rates (5.7% vs. 6.7%) compared to conventional LaTME.

Colorectal cancer, particularly rectal cancer, represents one of the most prevalent malignancies worldwide, with both its incidence and mortality rates ranking among the highest across all cancer types. The incidence of rectal cancer has been steadily increasing, driven by changes in lifestyle and dietary habits. Specifically, mid and low rectal cancers present significant challenges in surgical treatment due to their distinctive anatomical location. Surgical procedures must not only ensure complete tumor resection but also strike a balance between resection extent and anal function preservation, necessitating advanced surgical expertise. Additionally, postoperative complications, particularly anastomotic leakage, remain critical factors influencing patient recovery.

Treatment goals for mid and low rectal cancer typically include: (1) complete tumor resection to ensure no residual cancer cells; (2) maximizing anal function preservation to minimize postoperative incontinence and maintain quality of life; (3) reducing postoperative complications, particularly anastomotic leakage, a major contributor to poor recovery outcomes; and (4) enhancing overall patient quality of life and facilitating prompt recovery. However, despite advancements in conventional surgical techniques, the incidence of anastomotic leakage remains notably high, particularly in mid and low rectal cancer cases. Anastomotic leakage not only prolongs hospital stays but also significantly increases the risk of reoperation, imposing substantial physical and psychological burdens on patients [20]. These challenges have prompted clinical researchers and surgeons to continuously pursue more refined and effective surgical techniques. Recently, several modified surgical approaches have emerged, aimed at enhancing safety, improving surgical outcomes, and facilitating postoperative recovery while minimizing complication rates. The ongoing refinement and innovation of these techniques seek to provide better treatment options for patients with mid and low rectal cancer, ultimately enhancing prognosis and quality of life.

Total mesorectal excision (TME) remains the gold standard surgical approach for rectal cancer treatment. The core principle involves complete removal of the rectum and its mesorectum to achieve radical tumor resection and reduce the rate of local recurrence [21]. With advancements in laparoscopic technology, laparoscopic total mesorectal excision (LaTME) has progressively become one of the standard treatment modalities for mid and low rectal cancer [22]. However, LaTME presents certain limitations: (1) In patients with mid and low rectal cancer, the incidence of anastomotic leakage following LaTME remains relatively high. Anastomotic leakage following surgery can severely impede postoperative recovery, significantly prolong hospital stays, and exacerbate both the physical and psychological suffering of patients [23]. (2) To mitigate the risk of anastomotic leakage, LaTME frequently necessitates the creation of a protective stoma. However, protective stomas negatively affect both the quality of life and mental health of patients, and require a subsequent stoma reversal surgery, which increases both the economic burden and patient suffering [20]. Therefore, minimizing the need for protective stomas without elevating the anastomotic leakage rate is a critical focus in ongoing advancements in rectal cancer surgical techniques. Consequently, based on LaTME, numerous techniques and related research have been conducted to mitigate anastomotic complications, including preservation of the left colic artery, high ligation of the inferior mesenteric vein, integrated application of ICG technology during surgery, splenic flexure mobilization, and anastomotic reinforcement suturing. The innovative integration of these techniques forms the "PHISTA Technique", which optimizes intraoperative strategies to enhance the blood supply and tension at the anastomosis, reduce the incidence of anastomotic leakage, and diminish the need for protective stomas.

Low-level ligation of the inferior mesenteric artery (i.e., preservation of the LCA), represents a core advancement in the PHISTA Technique. Conventional LaTME emphasizes complete resection of the rectal mesorectum, typically involving high ligation of the IMA at its root to excise mesenteric root lymph nodes. However, high-level ligation may compromise blood supply to the proximal left colon, thereby increasing the risk of anastomotic leakage [24]. In contrast, the PHISTA Technique focuses on low-level ligation of the IMA and preservation of the LCA and its ascending branch, which significantly enhances blood supply to the proximal intestinal segment of the anastomosis [25]. A study by Sung et al. visually demonstrated, using ICG injection and infrared fluorescence imaging, that preserving the LCA ensures a more robust blood supply to the anastomosis [26]. Further research by Li et al. demonstrated that clamping the LCA markedly reduced the blood supply to the proximal intestinal segment of the anastomosis from 9.2 IU/s to 5.4 IU/s, thereby heightening the risk of anastomotic leakage [27]. Furthermore, a study by Huang et al. indicated that there was no statistically significant difference in the clearance of No. 253 lymph nodes between patients with and without LCA preservation [28]. In summary, these findings suggest that preserving the LCA not only enhances the blood supply to the anastomosis but also does not interfere with the clearance of No. 253 lymph nodes or adversely affect patients' oncological prognosis, while reducing the risk of postoperative anastomotic leakage. Overall, preservation of the left colic artery during radical resection of rectal cancer ensures improved blood supply to the proximal colon, fosters favorable.

In addition to left colic artery preservation, high ligation of the inferior mesenteric vein (IMV) constitutes another key aspect of the PHISTA Technique. The site of IMV ligation during rectal cancer surgery remains a subject of debate. Researchers in Europe and the United States advocate for high ligation of the IMV at the lower edge of the pancreas, in accordance with the principle of central vascular ligation. This approach is believed to prevent tumor spread, facilitate lymph node dissection at the vessel root, and increase bowel mobility, thus reducing anastomotic tension and facilitating bowel anastomosis [14, 29]. In contrast, Japanese researchers suggest ligating and transecting the IMV as distally as possible to avoid intestinal congestion [30]. In our center, the inferior mesenteric vein is ligated at a high position, specifically at the lower edge of the pancreas. Subsequently, the transverse mesocolon and splenic flexure mesocolon are dissected along the avascular plane towards the vascular arch, further alleviating anastomotic tension. Furthermore, due to the abundant venous collateral circulation within the mesocolon, no complications related to high IMV ligation have been observed in our patients thus far, providing preliminary evidence for its safety. However, it is important to note that the current sample size is limited. While initial results suggest that high ligation of the IMV is both safe and effective, its long-term clinical impact requires validation through larger-scale and multi-center studies. Future research, with the accumulation of more surgical cases and in-depth clinical data analysis, will allow for a more comprehensive evaluation of the clinical significance of high IMV ligation in rectal cancer surgery. Further optimization of this technique will offer more ideal treatment options for patients with mid and low rectal cancer, thereby reducing surgical difficulty, minimizing the risk of postoperative anastomotic leakage, and improving postoperative recovery and quality of life.

The complete or partial mobilization of the splenic flexure of the colon further enhances the efficacy of the PHISTA Technique. Mobilization of this anatomical region is of considerable clinical significance in the radical resection of rectal cancer. It facilitates comprehensive tumor excision, improves blood supply to the proximal intestinal segment, and alleviates tension at the anastomotic site, thereby reducing the risk of anastomotic leakage [31]. However, the question of whether to perform complete or partial mobilization of the splenic flexure remains a topic of ongoing debate. Some scholars advocate for transecting only the phrenocolic ligament, asserting that this method is relatively simple and does not significantly prolong the operative time [32]. In contrast, others recommend a more standardized approach, which involves not only cutting through the gastrocolic ligament, but also the splenocolic ligament, phrenocolic ligament, and the left portion of the transverse mesocolon, thereby achieving full mobilization of both the left half of the transverse colon and the splenic flexure [33]. At our center, the decision to sever ligaments is made based on the individual characteristics of each patient, in order to achieve effective mobilization of the intestinal segments. This targeted approach to splenic flexure mobilization allows for thorough detachment of both the intestinal segments and mesentery, while minimizing the risk of anastomotic leakage, though it may slightly increase the operation time. Furthermore, careful dissection around the ligaments and omentum adjacent to the colon helps reduce traction on the spleen, thereby minimizing the risk of iatrogenic splenic injury.

Additionally, the use of ICG fluorescence navigation technology has further improved the clinical efficacy of the PHISTA technique [8, 9, 10]. In 2006, Nagata et al. published the first research on the application of ICG in colorectal surgery [34]. As fluorescence imaging technology has matured, ICG has been increasingly used in colorectal surgery for intraoperative assessment of anastomotic blood perfusion and lymph node visualization, yielding significant results. (1) ICG-guided dissection of the No. 253 lymph nodes: The No. 253 lymph nodes is identified as the lymph node located along the inferior mesenteric artery (IMA), extending from the origin of the left colic artery to the point of origin of the IMA. This lymph node serves as the third station for lymphatic drainage in cases of rectal cancer and represents a significant pathway for the dissemination and metastasis of cancer cells, particularly in advanced stages of rectal cancer. The degree of dissection of the No. 253 lymph nodes has a direct influence on prognosis [35]. In recent years, ICG fluorescence navigation has played a significant role in the dissection of the No. 253 lymph nodes. Studies have demonstrated that ICG fluorescence imaging can visualize lymphatic drainage, thus improving the accuracy and completeness of lymph node resection in colorectal cancer surgery [36]. Another study investigated the use of ICG in radical lymph node dissection for sigmoid colon and rectal cancer, revealing that ICG imaging aids in complete dissection of D3 lymph nodes and identification of overlooked D3 lymph nodes, thereby improving the dissection rate, providing better surgical staging, and enhancing patient survival [37]. In summary, the use of ICG fluorescence imaging for lymph node dissection enhances detection range and improves surgical quality. (2) Beyond its role in lymph node visualization, ICG fluorescence also plays a crucial role in assessing anastomotic blood perfusion during surgery [26]. Anastomotic leakage (AL) is a severe complication following rectal cancer surgery, often leading to prolonged hospital stays, increased costs, and decreased survival. Poor anastomotic perfusion is a major risk factor [38, 39]. Therefore, intraoperative assessment of blood supply is crucial. NIR-ICG provides accurate information on anastomotic perfusion during rectal cancer surgery and is a highly valuable detection method. Jafari et al. observed 16 patients who underwent robotic low anterior resection (LAR) of the rectum. With ICG fluorescence angiography, 19% of cases achieved a more precise resection, indicating that ICG-NIR imaging can effectively reduce AL incidence [40]. In a multicenter phase II trial involving 90 LAR patients, ICG fluorescence guidance was used for all, with only 3% developing AL, significantly lower than those who did not use ICG guidance during the same period [41]. However, limitations exist in current ICG fluorescence systems. According to clinical practice [42], various factors such as the dose of ICG, duration of use, laparoscopic lens position, distance to the intestine, ambient light, NIR intensity, patient characteristics, and the surgeon’s subjective perception may influence the accuracy and consistency of ICG imaging, thereby impacting lymph node dissection and anastomotic perfusion assessment. Future development of more precise and stable ICG technologies is crucial for enhancing the thoroughness and accuracy of lymph node dissection, while providing an objective, quantitative tool for assessing anastomotic perfusion, thereby improving surgical precision and patient outcomes.

Finally, the reinforced suture of the anastomosis using barbed suture provides a more stable assurance for the PHISTA technique. The reinforcement of the anastomotic suture following digestive tract surgery can address potential defects at the anastomosis site [34]. The comprehensive application of the aforementioned techniques has ensured moderate tension and optimal blood perfusion at the anastomosis. Building on this foundation, the use of reinforced sutures with barbed sutures can further diminish the incidence of anastomotic leakage, particularly in high-risk patients such as those with diabetes and severe anemia [43]. Research indicates that reinforced suturing significantly reduces rates of anastomotic leakage, a finding corroborated by multiple meta-analyses [19, 44].

Short-term efficacy was a primary outcome measure in this study. The results indicated that the protective stoma rate in the PHISTA Technique group was 0%, which is significantly lower than the 31.7% observed in the conventional LaTME group (P < 0.001). Furthermore, the anastomotic leakage rate in the PHISTA Technique group was recorded at 5.7%, compared to 6.7% in the conventional LaTME group. Although the anastomotic leakage rate in the PHISTA Technique group was marginally lower than that of the conventional LaTME group, no statistically significant difference was found between these two groups (P > 0.05).Regarding intraoperative indicators—such as operation time, intraoperative blood loss, and total number of lymph nodes dissected—there were no statistically significant differences between the PHISTA Technique and conventional LaTME groups (P values were 0.116, 0.268, and 0.066, respectively). Similarly, for postoperative recovery indicators—including time to first postoperative exhaust, time to first postoperative defecation, and length of hospital stay—no statistically significant differences were noted between these two techniques (P values were 0.409 and 0.342 respectively). Additionally, while it is worth noting that operation time for patients undergoing PHISTA Technique was slightly longer than that for those receiving conventional LaTME (median times being 145 min vs.132 min), this difference did not reach statistical significance (P = 0.440). These findings suggest that while employing the PHISTA Technique can substantially reduce protective stoma rates without increasing anastomotic leakage rates beyond those seen with conventional LaTME methods—and may even result in a slight decrease—it also demonstrates comparable short-term recovery outcomes relative to conventional LaTME. This aligns with existing literature and further substantiates both safety and feasibility associated with utilizing the PHISTA Technique despite its marginally extended operation duration when compared to standard practices within this domain.

A pivotal finding of this study is that the PHISTA Technique allowed for the elimination of protective stomas without increasing the rate of anastomotic leakage. The question may arise as to why the leakage rate itself was not significantly reduced. This can be explained by several factors. First, the primary goal of the PHISTA protocol was not solely to reduce the absolute incidence of leakage, but to create a sufficiently safe anastomotic environment that obviates the need for a protective stoma. This goal was unequivocally achieved, as evidenced by a 0% stoma rate in the PHISTA group versus 31.7% in the control group. Second, the study was likely underpowered to detect a statistically significant difference in leakage rates, given the relatively low baseline incidence (6.7% in the conventional group) and the small absolute difference observed (5.7% vs. 6.7%). To prove a reduction in such a low-frequency event would require an impractically large sample size. Third, it is important to note that the observed leakage rate in the PHISTA group (5.7%) occurred without the safety net of a protective stoma, whereas a portion of the leaks in the conventional group (6.7%) occurred despite having a stoma. This contextual difference suggests that the PHISTA technique may represent a step toward more selective stoma use in clinical practice. While this finding is encouraging, it should be interpreted in light of the study’s methodological constraints, which are detailed in the limitations section below. Further validation through rigorously designed prospective studies is needed to confirm its role as a clinical advancement.

However, this study has several important limitations. First, and most critically, the non-randomized assignment based on patient preference after surgical counseling introduces substantial selection bias. As the decision was made outside a formal patient-preference trial framework and was inherently shaped by surgeon–patient discussions, unmeasured confounders related to health literacy, risk tolerance, or baseline fitness could have influenced both group assignment and outcomes. Second, the exclusion of patients receiving neoadjuvant therapy, while methodologically necessary to create a homogeneous cohort and isolate the technical outcomes from the confounding effects of radiotherapy, limits the generalizability of our findings to the broader population of mid-low rectal cancer patients. Third, the high proportion of poorly differentiated adenocarcinoma in our cohort, which may reflect our institutional referral patterns and pathological classification practices, may limit the direct extrapolation of our results to populations with a different distribution of histological subtypes. Fourth,in the conventional LaTME group, splenic flexure mobilization was not standardized but performed selectively based on intraoperative tension assessment. While reflecting real-world practice, this likely attenuated the technical contrast and observed outcome differences between groups. Fifth, the absence of an a priori sample size calculation and the reliance on a consecutive sample from a single institution likely resulted in insufficient power to detect statistically significant differences in anastomotic leakage rates. Thus, the observed comparable rates should be interpreted as indicating short-term safety within this cohort rather than definitive equivalence. Finally, the retrospective design and follow-up limited to the hospital stay precluded complete capture of anastomotic leaks and assessment of long-term oncological outcomes. Collectively, these limitations indicate that our findings are hypothesis-generating. Future multi-center, prospective randomized trials with appropriately calculated sample sizes, standardized protocols, and extended follow-up are warranted to validate the stoma-reduction potential of the PHISTA technique and establish its oncological non-inferiority, including in patients undergoing neoadjuvant therapy.

In conclusion, the findings of this study indicate that the PHISTA Technique represents a promising and feasible strategy in the treatment of mid and low rectal cancer. This integrated approach combines multiple advanced surgical techniques and aims to optimize both the surgical process and postoperative recovery conditions for patients with mid and low rectal cancer from various perspectives. As a result,It may provide a safe and effective alternative in patients. The PHISTA Technique reduces the rate of protective stoma without increasing the incidence of anastomotic leakage. Furthermore, according to the ISREC classification, the severity of anastomotic leakage in the PHISTA group was milder than that in the conventional LaTME group, with no cases of grade C leakage requiring reoperation. However, due to the limited number of anastomotic leak events and the lack of statistical significance in incidence rates between groups, these observations regarding severity should be interpreted cautiously. The potential impact of the PHISTA technique on anastomotic leak severity remains a hypothesis that warrants further investigation in larger-scale studies. Nonetheless, by reducing preventive stoma rates, this approach may still enhance patients' quality of life by alleviating the economic burden and psychological stress associated with subsequent stoma reversal surgery.

Although PHISTA Technique has shown substantial theoretical and practical advantages, it also entails several potential limitations: (1) Technical learning curve: The application of PHISTA Technique requires advanced technical proficiency from the surgeon, necessitating specialized training and experience accumulation. Novices may face challenges in mastering this technique. (2) Extended operation time: Due to its inherent complexity, the operation time for PHISTA Technique is somewhat longer than conventional LaTME procedures. However, the authors argue that as surgeons gain experience through practice, the additional time required for certain surgical steps may decrease. (3) Study limitations: This study is a single-center retrospective analysis with a relatively small sample size, which may limit the generalizability of our findings. Future multi-center, large-scale clinical studies are crucial for validating these results. (4) Long-term oncological prognosis validation: While PHISTA Technique has demonstrated promising short-term efficacy, its long-term oncological outcomes remain.

unexamined. Therefore, future multi-center, prospective studies with larger sample sizes and extended follow-up periods are necessary to further evaluate the oncological effects and safety profile of PHISTA Technique.

Conclusion

In conclusion, this single-center retrospective study provides preliminary, hypothesis-generating evidence regarding the feasibility and short-term outcomes of the PHISTA Technique. Our findings suggest that in selected patients at a specialized center, the PHISTA approach may offer a profound benefit in reducing the need for a protective stoma without increasing short-term complications, particularly anastomotic leakage, compared to conventional LaTME. The technique's impact on long-term oncological outcomes awaits further evaluation. However, due to the study's non-randomized design, limited sample size, and potential selection bias, these results should be interpreted as exploratory and are not yet sufficient to recommend changes in clinical practice. Further validation through larger, multi-center, prospective randomized trials is necessary to confirm the efficacy and generalizability of the PHISTA Technique before it can be considered for broader adoption.

Authors’ contributions

All authors read and approved the final manuscript. Jingshu He made a tremendous contribution to the revision of the article. Guodong Zhao provided relevant knowledge of statistics, which played a significant role in the revision. Sufen Han and Hao Ji participated in writing the main text of the manuscript. Jiahao Zhao is responsible for collecting materials, methods and data. Jiayi Zhang and LuZhao prepared these figures. Wei Chen and Yichao Ma are tidying up the table. Tang Dong supervised the research as the corresponding author. All authors participated in the review and revision.

Funding

This work was supported by the Graduate Research- Innovation Project in Jiangsu province [No. SJCX21_1644], the Academic Science and Technology Innovation Fund for College Students [No. 202011117056Y], Social development project of key R & D plan of Jiangsu Provincial Department of science, technology [No. BE2022773] and The Nantong Municipal Health Commission Project [MSZ2023097]. The funding bodies had no role in the design of the study; in the collection, analysis, and interpretation of the data; and in the writing the manuscript.

Data availability

The data that underpin the findings of this study can be obtained from the corresponding author upon request.

Declarations

Ethics approval and consent to participate

All surgical procedures were conducted by the same surgical team to ensure consistency in technique and approach. The surgical team received specialized training in the PHISTA Technique prior to patient enrollment. During the informed consent process, the innovative nature of the PHISTA Technique was explicitly explained to all eligible patients. This included a detailed discussion that while the individual technical components were established practices in colorectal surgery, their combination into the PHISTA protocol was novel, and high-level evidence (such as from large, randomized trials) specifically for this bundled approach was still evolving. The potential benefits (primarily the potential to avoid a stoma) were balanced against the potential uncertainties and the longer operative time. The established safety and outcomes of conventional LaTME were also thoroughly presented. After being fully informed, patients were given the autonomy to freely choose their preferred surgical method. Informed consent was obtained from all participants involved in this study, which was approved by the Ethics Committee of Northern Jiangsu People's Hospital in Jiangsu Province (No. 2024ky343).

Competing interests

The authors declare no competing interests.