To investigate the surgical methods to reduce the complications after rectal low double anastomosis. METHODS: From February 2010 to June 2014, the clinical data of 56 patients with low to medium rectal cancer who underwent laparoscopic low rectal double anastomosis at the time of radical rectal cancer treatment (observation group) in the Department of General Surgery of the First Affiliated Hospital of Soochow University were retrospectively analyzed, and 64 patients with low to medium rectal cancer who underwent laparoscopic low rectal double anastomosis at the time of radical rectal cancer treatment (control group) at the same time were compared and studied. The indexes such as gender, age, tumor size, distance of lower margin from the dentate line and tumor stage were paired one by one.
In the observation group, the distal end of the rectum was cut and closed in a vertical direction instead of a horizontal direction; the intestine-intestine anastomosis was performed in an “end-angle” manner to remove the angular part of the distal end of the rectum on the closure line; the lower angular part of the closure end was removed by means of a vascular clip; and the only part of the rectum formed after the double anastomosis was reinforced with absorbable sutures. A “T” shaped intersection of the staple line (“danger triangle”) was formed after the double rectal anastomosis was reinforced with absorbable sutures. In the control group, the laparoscopic low rectal double anastomosis was completed by conventional methods, and the two corners of the distal closed rectum and the two “danger triangles” of the double anastomosis were not treated. Results: The general clinical data of the two groups were not statistically different (P>0.05) and were comparable. There were no significant differences in intraoperative bleeding, postoperative drainage, postoperative anastomotic bleeding, anal venting time and hospitalization time between the two groups (P>0.05).
There were significant differences in operative elapsed time, number of postoperative anastomotic fistulas, number of bowel movements, posterior urgency, and postoperative reoperative fistulas (P<0.05)< span="">. Conclusion: The modified rectal low double anastomosis performed in this study significantly reduced the occurrence of postoperative anastomotic fistula and complications such as “post-rectal low anterior resection syndrome”. The advent and promotion of the double stapling technique (DST) [1] has greatly improved the rate of anus preservation after radical surgery for patients with low and intermediate rectal cancer [2] and has greatly contributed to the improvement of patients’ postoperative quality of life, but postoperative complications such as postoperative anastomotic fistula [3] and “post-anorectal resection syndrome” [4] are still a problem. However, postoperative complications such as post-operative anastomotic fistula [3] and “post-anastomotic anterior rectal resection syndrome” [4] are still major clinical problems, so we designed and implemented a modified rectal low double anastomosis method by removing the two corners of the distal closed end of the rectum and strengthening the “T” intersection of the staple line (danger triangle) during laparoscopic low rectal double anastomosis. The clinical results were good and are reported as follows.
1.Data and methods
1.1 General information
From 120 patients with low to medium rectal cancer who were admitted to our department and completed Dixon’s radical surgery between February 2010 and June 2014, 56 patients who completed modified rectal low double anastomosis under laparoscopy were selected (observation group), 38 males and 18 females; age 34-88 years, mean age 60.5 years; the lower edge of the tumor was ≥5 cm from the dentate line TNM stage: 30 cases of stage I+II and 26 cases of stage III. In the same period, 64 patients (control group) completed conventional rectal low-grade double anastomosis under laparoscopy, including 38 males and 26 females; age 31-80 years, mean age 59.5 years; tumor lower margin ≥5 cm from the dentate line in 18 cases, <5 cm in 46 cases; histological types: 9 cases of highly differentiated adenocarcinoma, 38 cases of moderately differentiated adenocarcinoma, 14 cases of poorly differentiated adenocarcinoma, and 3 cases of other pathological types; postoperative TNM stage: 35 cases in stage I+II, 29 cases in stage III.
1.2 Surgical method
All cases enrolled in this study underwent laparoscopic radical resection of lower rectum (anterior rectal resection), which was performed according to the principle of total mesoretal excision (TME). In the case of low rectal double anastomosis, the distal rectal cut closure was changed from horizontal to vertical in the observation group, see Fig. 1. The circular anastomosis was delivered into the distal rectum through the anus, and the tip of the upper corner of the distal rectal closure line was pre-cut with an ultrasonic knife, and the central rod protruded from this incision, see Fig. 2, and was connected to the nail holder and fired to complete the intestine-intestine “end-angle” anastomosis. The center rod extends from this incision, see Figure 2, and is connected to the peg holder and fired to complete the intestine-intestine “end-angle” anastomosis, thus directly removing the upper corner of the distal rectal closure. The lower corner of this closure margin is clamped with a vascular clip, see Figure 3. A staple line “T” intersection is formed after the above intestine-intestine “end-angle” anastomosis is reinforced with 3-0 absorbable suture (“danger triangle”), see Figure 4. “In the control group, the distal rectum was closed by cutting horizontally according to the conventional operation method, and the central rod was rotated out of the middle part of the distal rectal closure line (avoiding the staple line so as not to tear the closure line of the distal rectal break), and the intestine-intestine “end-to-end” anastomosis was performed, and the double anastomosis was not treated otherwise.
1.3 Statistical analysis
All data were analyzed statistically using SPSS17.0 software, and t-test was used for normal distribution of measurement data, and rank sum test was used for skewed distribution; chi-square test was used for counting data, and P<0.05< span="">was considered statistically significant.
2, Results
There were no fatal cases in both groups. There were no statistically significant differences in the clinical general data of gender, age, tumor location, histological type, and TNM stage between the two groups of patients in A and B (P>0.05), which were comparable, as shown in Table 1. There were significant differences in the operative elapsed time (211.18±90.55 vs. 173.82±57.43, P=0.010) and the number of postoperative bowel movements (1.98±1.05 vs. 2.65±1.08, P=0.001) between the two groups of patients. Postoperative anastomotic complications were significantly lower in the observation group (1.8% vs. 12.3%, P=0.030), the incidence of postoperative anastomotic fistula (3.6% vs. 13.8%, P=0.047), postoperative reoperative fistula (0% vs. 10.7%, P=0.031) than in the control group, and the incidence of postoperative anastomotic bleeding (3.6% vs. 13.8%, P=0.047). Postoperative anastomotic bleeding (1.8% vs. 4.6%, P=0.734) was not statistically significant in the two groups, as shown in Table 3.
3, Discussion
Although the technique of low rectal double anastomosis has led to a substantial increase in the rate of anus preservation in patients with low to medium rectal cancer, postoperative anastomotic fistula is still inevitable, and the incidence is generally reported to be 4%-20% at home and abroad [5]. Analyzing the reasons for this, the author believes that in addition to the currently recognized causes such as the blood flow of the anastomotic intestinal tube and the tension of the anastomosis, the two corners remaining at the distal closed end of the double anastomosis rectum are undoubtedly two important hidden dangers, because the damage caused by the extrusion of the intestinal tissue at this place after cutting and closing is relatively greater (the intestinal tube folds back and overlaps here), so the tissue structure at the tip of the two corners is relatively weak, which is certainly an important anatomical and histological basis for postoperative fistula This is an important anatomical and histological basis for postoperative fistulae [6]. There are reports of sutures to strengthen the two corners [7]; there are also studies of intestinal-intestinal anastomosis with sutures pulled into the anastomotic “staple compartment” so that no corners remain after the anastomosis [8]. However, more studies on the angle of stump closure have been reported on “diverticulitis” [9], while their anatomical and histological relevance to the development of fistula after low rectal double anastomosis is rarely seen. The exact location of the fistula after low rectal double anastomosis has also been rarely reported or studied.
The other two points where fistulas are likely to occur in low rectal double anastomoses are: the “T” shaped intersection of the two staple lines after conventional low rectal double anastomosis (the “danger triangle”) [10], which is an area of hidden tissue deficiency and is a favored area for fistulas. It is inevitable that this is the area of hidden tissue deficiency, and it is a good area for fistula. Although many scholars have noted its danger and called it the “danger triangle”, and a number of papers have mentioned and reinforced the anastomosis with sutures, the two “danger triangles” have not been exactly described for suture reinforcement [11]. No studies have been retrieved on the targeted management of both of these favored areas that predispose to low rectal double anastomotic fistula.
Preventive management of these two risk areas is rarely performed in clinical practice. The reasons for this include reliance on instruments, confidence and luck of the surgeon, but an undeniable reason is that it is difficult to operate in these two risk areas. Therefore, how to facilitate the operation and reliably remove the hidden danger of these two areas has become the focus of our study to reduce the complications after rectal low double anastomosis.
In recent years, “post-rectal low anterior resection syndrome” [12] has attracted more and more attention from clinical workers, and the existing studies suggest that the anatomical basis of this syndrome is due to the diverticular effect of the two residual angles of the distal rectal closure after low double anastomosis and the occurrence of inflammation, which causes postoperative anorectal irritation and affects the postoperative rectal storage. and affects the postoperative rectal storage and defecation function. Patients may experience postoperative urgency and increased frequency of defecation. Therefore, if the two corners of the distal rectal closure are removed, the possibility of diverticulitis in the corners of the rectal double anastomosis is fundamentally eliminated, which theoretically has a positive effect on reducing the “post-rectal hyporectal resection syndrome”.
Because of the low position of the rectal low double anastomosis, the operation space is small and the field of view is limited, so it is extremely difficult to operate on it in traditional open surgery, especially to strengthen the suture, and clinically most of the operators will only perform the air leak test on the anastomosis after completing the anastomotic strike, and will not perform other operations, otherwise the secondary damage to the anastomosis may be caused by pulling and other operations, increasing the risk of fistula.
Although laparoscopic surgery allows a clear and magnified view and deep operations are possible, laparoscopic suturing and visualization require a high level of operator skill and it is time-consuming and laborious to perform these operations. This is undoubtedly an important constraint to the operation of the double anastomosis. Another objective constraint is that the two corners of the distal rectal closure and the two “danger triangles” of the conventional double anastomosis are located on the horizontal closure line of the distal rectum and on both sides of the intestinal canal, so the operation is very awkward and the field of view is very limited, and it is not easy to take into account both left and right, so the operator is rarely willing to take too much trouble for these potential complications. Therefore, operators are rarely willing to bother with these potential complications.
For these theoretical and practical reasons, the present study was designed to close the distal rectum by cutting vertically so that the two corners are at the upper and lower ends of the distal rectal closure line, thus greatly facilitating the observation and operation of the two corners and facilitating the removal of the central rod of the anastomosis directly after performing the intestine-intestine “end-corner” anastomosis by piercing the tip of the upper corner. This angle can be removed directly after performing an “end-to-angle” intestinal anastomosis. The lower horn can also be easily lifted under direct vision and clamped with a vascular clip, thus strengthening the weak area of the horn and eliminating the diverticular cavity of the horn.
This operation allows for easy and simple removal of the angle. In addition, the operation is designed so that only a “T” shaped intersection (the “danger triangle”) remains at the staple line after completion of the intestinal-intestinal “end-angle” anastomosis between the intestinal canal and the upper horn, and so that It is convenient to complete the reinforced suture of the pulpy muscle layer under direct vision (Figure 4), and the exposure is also easier; at the same time, it avoids the formation of two “danger triangles” on the left and right side when the distal side of the rectum is closed by conventional horizontal cutting and the second anastomosis is performed. This has positive significance in reducing the difficulty and intensity of the operation to strengthen the “dangerous triangle” and reducing the probability of anastomotic fistula.
The data from this study also confirmed the above: the observation group was significantly better than the control group in the occurrence of fistula (1.8% vs. 12.3%, P=0.030), posterior urgency (3.6% vs. 13.8%, P=0.047), and frequency of defecation (1.98±1.05 vs. 2.65±1.08, P=0.001). Although the intraoperative time was longer in the observation group than in the control group (211.18±90.55 vs. 173.82±57.43, P=0.010), it was gradually shortened with proficiency in the operation technique, so that the future dissemination of this operation will not be significantly limited by the duration of the operation.
In this study, the laparoscopic modified rectal low double anastomosis was designed as follows: the distal rectum was closed with a vertical cut; the intestine-intestine anastomosis was performed in an “end-angle” fashion, and the upper corner of the closure line of the distal rectum was removed directly; the lower corner of the closure line was removed with a vascular clip; and the double anastomosis was closed with a reinforced absorbable suture. A “dangerous triangle” was formed after the double anastomosis. The anatomical and histological basis for fistulas and angular diverticulitis after low rectal double anastomosis was eliminated. The modified rectal low double anastomosis avoids the dilemma of prophylactic reinforcement of the two corners of the distal rectal closure and the two “dangerous triangles” during the conventional rectal low double anastomosis, simplifies and facilitates the operation, and is easy to master and promote. The clinical control study also showed a good effect of reducing postoperative complications of rectal low double anastomosis, which is worthy of further study and application.