The adequacy of the marginal blood-supply to the left colon after high ligation of the inferior mesenteric artery during excision of the rectum

Inferior Mesenteric Artery Ligation Level in Rectal Cancer Surgery beyond Conventions: A Review

Within the intricate field of rectal cancer surgery, the contentious debate over the optimal level of ligation of the inferior mesenteric artery (IMA) persists as an ongoing discussion, influencing surgical approaches and patient outcomes. This narrative review incorporates historical perspectives, technical considerations, and functional as well as oncological outcomes, addressing key questions related to anastomotic leakage risks, genitourinary function, and oncological concerns, providing a more critical understanding of the well-known inconclusive evidence. Beyond the dichotomy of high versus low tie, it navigates the complexities of colorectal cancer surgery with a fresh perspective, posing a transformative question: "Is low tie ligation truly reproducible?" Considering a multidimensional approach that enhances patient outcomes by integrating the surgeon, patient, technique, and technology, instead of a rigid and categorical statement, we argued that a balanced response to this challenging question may require compromise.

Clinical impact of inferior mesenteric vein preservation during left hemicolectomy with low ligation of the inferior mesenteric artery for distal transverse and descending colon cancers: A comparative study based on computed tomography

Purpose

Presence of a long remnant sigmoid colon after left hemicolectomy with inferior mesenteric vein (IMV) ligation for distal transverse and descending colon cancers may be a risk factor for venous ischemia. This study aimed to evaluate the clinical impact of IMV preservation in patients who underwent left hemicolectomy with inferior mesenteric artery (IMA) preservation.

Methods

We included 155 patients who underwent left hemicolectomy with IMA preservation for distal transverse and descending colon cancers from 2003 to 2020. Technical success of IMV preservation was determined by assessing pre- and post-operative patency of the IMV on computed tomography (CT) by an abdominal radiologist. Intestinal complications comprising ulceration, stricture, venous engorgement, and colitis in remnant colon were compared between the IMV preservation and ligation groups.

Results

IMV was preserved in 22 (14.2%) and ligated in 133 (85.8%) patients. Surgical time, postoperative recovery outcomes, and number of harvested lymph nodes were similar in both groups. The technical success of IMV preservation was 81.8%. Intestinal complications were less common in the preservation group than in the IMV ligation group (4.5% vs. 23.3%, P=0.048). The complications in the IMV ligation group were anastomotic ulcer (n=2), anastomotic stricture (n=4), venous engorgement of the remnant distal colon (n=4), and colitis in the distal colon (n=21).

Conclusions

IMV preservation may be beneficial after left hemicolectomy with IMA preservation for distal transverse and descending colon cancers. We suggest that IMV preservation might be considered when long remnant sigmoid colon is expected during left hemicolectomy with low ligation of IMA.

Prospective Study Comparing Clinical vs Indocyanine Green Fluorescence-Based Assessment of Line of Transection in Robotic Rectal Cancer Surgery-Indian Study

Anastomotic leakage continues to be the most feared postoperative complications in rectal surgery with negative impact on both short- and long-term outcomes. Fortunately, new surgical strategies have helped to offset this complication and improve surgical outcomes. Traditionally, perfusion is assessed by intraoperative visual judgment by the surgeon. These subjective methods lack predictive accuracy resulting in either excess or insufficient colonic resection. Indocyanine green (ICG) fluorescence has shown promise in identifying the adequacy of perfusion. After injection of ICG, the system projected high-resolution near-infrared real-time images of blood flow in mesentery and bowel wall. This novel imaging method is used intraoperatively for taking real-time informed decisions. We conducted a single institutional prospective study to identify the feasibility of ICG identification of vascularity of anastomotic site and its impact on the change of plan of surgical management in robotic rectal cancer surgery. Between September 2017 and April 2019, fifty patients undergoing robotic rectal cancer surgery were included in the study. The aim was to analyze the feasibility and clinical benefit of intraoperative near-infrared fluorescence imaging in determining the line of transection in comparison with the traditional method. Line of proximal transection of the bowel subjectively assessed by the surgical team was marked point B and that after ICG injection was marked point A if moved proximally and point C if moved distally. The vascular anatomy was clearly identified with no intraoperative or injection-related adverse effects. Of the 50 patients, the line of transaction remained the same in 6 patients (12%). Based on the fluorescence imaging, the surgical team opted for further proximal change of the transection line up to an "adequate" fluorescent portion in 3 patients (6%) and distally in 41 patients (82%). ICG-based infrared image-guided localization gives a real-time image of colon vascularity possibly affecting anastomotic leak. The ICG fluorescence imaging system is a simple, safe, and useful technique, performed within a short time, and it enables visual evaluation of the blood flow in the intestinal tract prior to anastomosis. Larger studies are needed before this can become the standard of care.

Safety and effectiveness of high ligation of the inferior mesenteric artery for cancer of the descending colon under indocyanine green fluorescence imaging: a pilot study

BACKGROUND

Complete mesocolic excision with central vascular ligation is a standard advanced technique for achieving favorable long-term oncological outcomes in colon cancer surgery. Clinical evidence abounds demonstrating the safety of high ligation of the inferior mesenteric artery (IMA) for sigmoid colon cancer but is scarce for descending colon cancer. A major concern is the blood supply to the remnant distal sigmoid colon, especially for cases with a long sigmoid colon. We sought to clarify the safety and feasibility of high ligation of the IMA in surgery for descending colon cancer using indocyanine green (ICG) fluorescence imaging.

METHODS

In this prospective single-center pilot study, we examined 20 patients with descending colon cancer who underwent laparoscopic colectomy between April 2018 and September 2019. Following full mobilization and division of the proximal colonic mesentery, we temporarily clamped the root of the IMA and performed ICG fluorescence imaging of the blood flow to the sigmoid colon. The postoperative anastomosis-related complications (primary endpoint) and length of viable remnant colon, and the number of lymph nodes retrieved (secondary endpoints) were evaluated and compared with historical controls who underwent conventional IMA-preserving surgery (n = 20).

RESULTS

Blood flow reached 40 (17-66) cm retrograde from the peritoneal reflection, even after IMA clamping. Accordingly, IMA high ligation was performed in all cases. No anastomotic anastomosis-related complications occurred in each group. Retrieved total lymph nodes were higher in number in the ICG-guided group than in the conventional group (p = 0.035). Specifically, more principal nodes were retrieved in the ICG-guided group, compared with the conventional group (p = 0.023). However, the distal margin was not as long compared with the conventional group.

CONCLUSION

We demonstrated the safety and feasibility of high ligation of the IMA for descending colon cancer without sacrificing additional distal colon using fluorescence evaluation of blood flow in the remnant colon.

Usefulness of blood flow evaluation by indocyanine green fluorescence system in laparoscopic anterior resection

BACKGROUND

One of the major cause of anastomotic leakage (AL) in anterior resection of the rectum is insufficient blood flow of the remnant colon. The indocyanine green fluorescence system (ICG-FS) can visualize the blood flow of organs intra-operatively. The aim of this study is to investigate the usefulness of ICG-FS for evaluating the blood flow of the remnant colon in laparoscopic anterior resection.

MATERIALS AND METHODS

Rectal cancer patients (n=24) who underwent laparoscopic anterior resection were included in this study. After resection of the rectum, 7.5mg of ICG was administered intravenously, and the blood flow of the oral stump was evaluated by the ICG-FS. The relationship between the fluorescence time (FT) of the oral stump and AL was investigated retrospectively.

RESULT

Two of twenty-four patients (8.3%) suffered AL. The FT of these two cases were over 60 seconds. In the case with the FT was over 80 seconds, we performed additional resection of the late fluorescence portion of the remnant colon and could avoid AL. In patients whose FT was under 60 seconds, no patients suffered AL.

CONCLUSION

ICG-FS may be useful for evaluating the blood flow of the remnant colon to avoid AL in laparoscopic anterior resection. J. Med. Invest. 66 : 65-69, February, 2019.

Preservation versus non-preservation of left colic artery in colorectal cancer surgery: An updated systematic review and meta-analysis

BACKGROUND

It remains unclear whether or not preservation of the left colic artery (LCA) for colorectal cancer surgery. The objective of this updated systematic review and meta-analysis is to evaluate the current scientific evidence of LCA non-preservation versus LCA preservation in colorectal cancer surgery.

METHODS

A systematic search was conducted in the Medline, Embase, PubMed, Cochrane Library, ClinicalTrials, Web of Science, China National Knowledge Infrastructure and Chinese BioMedical Literature Database, and reference without limits. Quality of studies was evaluated by using the Newcastle-Ottawa scale and the Cochrane Collaboration's tool for assessing the risk of bias. Effective sizes were pooled under a random- or fixed-effects model. The funnel plot was used to assess the publication bias. The outcomes of interest were oncologic consideration including the number of apical lymph nodes, overall recurrence, 5-years overall survival, and 5-years disease-free survival (DFS); safety consideration including overall 30-day postoperative morbidity and overall 30-day postoperative mortality; anatomic consideration including anastomotic circulation, anastomotic leakage, urogenital, and defaecatory dysfunction.

RESULTS

Twenty-four studies including 4 randomized controlled trials (RCTs) and 20 cohort studies with a total of 8456 patients (4058 patients underwent LCA non-preservation surgery vs 4398 patients underwent LCA preservation surgery) were enrolled in this meta-analysis. The preservation of LCA was associated with significantly less anastomotic leakage (odds ratio 1.23, 95% confidence interval 1.02-1.48, P = .03). In term of sexual dysfunction, urinary retention, the number of apical lymph nodes, and long-term oncologic outcomes, there were no significant differences between the LCA non-preservation and LCA preservation group. It was hard to draw definitive conclusions on other outcomes including operation time, blood loss, the first postoperative exhaust time, and perioperative morbidity and mortality for insufficient data and highly significant heterogeneity among studies.

CONCLUSIONS

The pooled data provided evidence to support the LCA preservation preferred over LCA non-preservation in anastomotic leakage. Future more large-volume, well-designed RCTs with extensive follow-up are needed to draw a definitive conclusion on this dilemma.

High ligation of the inferior mesenteric artery during sigmoid colon and rectal cancer surgery increases the risk of anastomotic leakage: a meta-analysis

BACKGROUND

The ideal level of ligation of the inferior mesenteric artery (IMA) during curative resection of sigmoid colon and rectal cancer is still controversial. The aim of this meta-analysis was to examine the impact of high ligation and low ligation of the IMA on anastomotic leakage, overall morbidity, postoperative mortality, and oncological outcomes in patients undergoing surgery for sigmoid colon and rectal cancer.

METHODS

PubMed, EMBASE, Web of Science, and BioMed Central databases were searched to identify relevant articles published from May 1953 to March 2018. A total of 18 articles (14 non-randomized studies and 4 randomized clinical trials) were identified. Review Manager 5.3 software was used for analysis of data. The pooled odds ratio (OR) and weighted mean difference (WMD), with 95% CI, were calculated using either the fixed effects model or random effects model.

RESULTS

Of the 5917 patients included in this meta-analysis, 3652 patients underwent low ligation of the IMA and 2265 patients underwent high ligation of the IMA. Anastomotic leakage rate was 9.8% in high ligation patients vs. 7.0% in low ligation patients; the risk of anastomotic leakage was significantly higher in high ligation patients (OR = 1.33; 95% CI 1.10-1.62; P = 0.004). What is more, overall morbidity was also significantly higher in high ligation patients (OR = 1.39; 95% CI, 1.05-1.68; P = 0.05). Postoperative mortality, number of harvested lymph nodes, overall recurrence rate, and 5-year survival rate did not differ significantly between the two groups.

CONCLUSION

Low ligation of the IMA during curative resection of sigmoid colon and rectal cancer appears to be associated with lower risk of anastomotic leakage and overall morbidity. However, there was no significant advantage of low ligation over high ligation of IMA in terms of postoperative mortality, the number of harvested lymph nodes, overall recurrence rate, or 5-year survival rate.

Resection of Colorectal Cancer With Versus Without Preservation of Inferior Mesenteric Artery

OBJECTIVE

To assess the clinical significance of preservation of the inferior mesenteric artery (IMA) in comparison with IMA ligation in surgery for sigmoid colon or rectal (colorectal) cancer.

METHODS

Consecutive patients (n=862) with colorectal cancer who underwent intended surgical resection of the main tumor between 1986 and 2011 were retrospectively analyzed. The patients were divided into 2 groups: IMA preserved (n=745) and IMA ligated (n=117).

RESULTS

No significant difference was observed in incidence of advanced stage III or IV disease between the 2 groups (P=0.56 and 0.51, respectively), whereas a longer operation time (287 [95 to 700] vs. 215 [60 to 900] min, respectively; P<0.001) and greater amount of intraoperative bleeding (595 [15 to 4530] vs. 235 [1 to 11565] mL, respectively; P<0.001) were observed in the IMA-ligated group. The overall incidence of surgery-related complications was higher in the IMA-ligated group than in the IMA-preserved group (53.0% vs. 38.5%, respectively; P=0.003). Urinary dysfunction and abdominal abscess were significantly more frequent in the IMA-ligated group (11.1% vs. 4.0%, P=0.001; and 6.8% vs. 2.6%, P=0.01, respectively), and postoperative hospitalization was longer (11 to 140, median 28 vs. 5 to 153, median 19 d, respectively; P<0.001). No significant difference was found in overall survival rate between the 2 groups.

CONCLUSIONS

For colorectal cancer resection, IMA preservation may be no change to IMA ligation as to patient' survival, with small risk of operative morbidity.

Indocyanine green-enhanced fluorescence to assess bowel perfusion during laparoscopic colorectal resection

Aims

Anastomotic leakage after colorectal surgery is a severe complication. One possible cause of anastomotic leakage is insufficient vascular supply. The aim of this study was to evaluate the feasibility and the usefulness of intraoperative assessment of vascular anastomotic perfusion in colorectal surgery using indocyanine green (ICG)-enhanced fluorescence.

Methods

Between May 2013 and October 2014, all anastomosis and resection margins in colorectal surgery were investigated using fluorescence angiography (KARL STORZ GmbH & Co. KG, Tuttlingen, Germany) intraoperatively to assess colonic perfusion prior to and after completion of the anastomosis, both in right and left colectomies.

Results

A total of 107 patients undergoing colorectal laparoscopic resections were enrolled: 40 right colectomies, 10 splenic flexure segmental resections, 35 left colectomies, and 22 anterior resections. In 90 % of cases, the indication for surgery was cancer and high ligation of vessels was performed. Based on the fluorescence intensity, the surgical team judged the distal part of the proximal bowel to be anastomosed insufficiently perfused in 4/107 patients (two anterior, one sigmoid and one segmental splenic flexure resections for cancer), and consequently, further proximal “re-resection” up to a “fluorescent” portion was performed. None of these patients had a clinical leak. The overall morbidity rate was 30 %; one patient undergoing right colectomy had an anastomotic leakage, apparently unrelated to ischemia; there were no clinical evident anastomotic leakages in colorectal resections including all low anterior resections.

Conclusions

ICG-enhanced fluorescent angiography provides useful intraoperative information about the vascular perfusion during colorectal surgery and may lead to change the site of resection and/or anastomosis, possibly affecting the anastomotic leak rate. Larger further randomized prospective trials are needed to validate this new technique.

Visualization of Lymph/Blood Flow in Laparoscopic Colorectal Cancer Surgery by ICG Fluorescence Imaging (Lap-IGFI)

PURPOSE

In laparoscopic colorectal cancer (Lap-CRC) surgery, determination of a suitable mesentery division line and the appropriate degree of lymphadenectomy by tracing the blood supply is critical. We performed visualization of the lymph and blood flow by laparoscopic indocyanine green (ICG) fluorescence imaging (Lap-IGFI).

METHODS

ICG is injected into the submucosa near the tumor via colonoscopy, and the lymph flow is observed. Intestinal blood flow is evaluated by administering ICG intravenously.

RESULTS

For lymph flow, visualization of the main lymph node basin helped to determine the surgical division line for cases in which the blood flow was not completely visualized. Lap-IGFI changed the surgical plan of the lymphadenectomy in 23.5 %. In our experience, the metastatic rate of ICG-positive nodes was 10.0 %, and the metastatic rate of ICG-negative nodes was 5.3 %. Furthermore, there were no metastatic nodes that were ICG negative more than 5 cm from the tumor. For blood flow, the blood flow distribution of the intestinal wall from the last branch of the vasa recta of the anastomotic site was clearly visualized and proved useful in choosing the extent of intestinal resection. Lap-IGFI changed the surgical plan of the extensive intestinal resection in 16.7 %.

CONCLUSIONS

Lap-IGFI can noninvasively provide detailed lymph and blood flow information and is a useful device to aid in the accurate identification of individual patients' lymph drainage. This helps dictate adequate lymphadenectomy and the extent of intestinal resection in Lap-CRC surgery.

Marginal artery stump pressure in left colic artery-preserving rectal cancer surgery: a clinical trial

BACKGROUND

The aim of this clinical trial is to evaluate the influence of high and low ligation of the inferior mesenteric artery with apical lymph node dissection on the anastomotic blood supply, lymph node retrieval rate, operative time and anastomotic leakage rate in rectal cancer surgery.

METHODS

A total of 57 Chinese patients were randomly distributed into group A and group B and underwent radical resection of rectal cancer. Patients in group A underwent high ligation of the inferior mesenteric artery, and patients in group B underwent apical lymph node resection around the root of the inferior mesenteric artery with preservation of the left colic artery. The marginal artery stump pressure was measured after colon and artery reconstruction. Systemic pressure, distal colon length, operative time and lymph node retrieval rate were measured and recorded. The results were analysed and related to patient characteristics and post-operative complications.

RESULTS

The anastomotic blood supply negatively and linearly correlated with age and distal colon length and showed a positive linear correlation with systemic pressure. Patients who received low ligation with apical lymph node dissection had a better anastomotic blood supply than those who received high ligation. No differences were found in lymph node retrieval rate, operative time and anastomotic leakage rate. Anastomotic leakage was associated with a worse anastomotic blood supply.

CONCLUSIONS

Low ligation with apical lymph node dissection in rectal cancer treatment provides better anastomotic blood supply but is not associated with differences in node retrieval rate or operation time.

The relation between inferior mesenteric vein ligation and collateral vessels to splenic flexure: anatomical landmarks, technical precautions and clinical significance

PURPOSE

Our aim to assess clinical significance of the relation between inferior mesenteric vein ligation and collateral blood supply (meandering mesenteric artery) to the splenic flexure with elaboration more in anatomical landmarks and technical tips.

MATERIALS AND METHODS

We review the literature regarding the significance of the collateral vessels around inferior mesenteric vein (IMV) root and provide our prospective operative findings, anatomical landmarks and technical tips. We analyzed the incidence and pattern of anatomic variation of collateral vessels around the IMV.

RESULTS

A total of 30 consecutive patients have been prospectively observed in a period between June 25-2012 and September 7-2012. Nineteen males and eleven females with mean age of 63 years. Major colorectal procedures were included. There were three anatomical types proposed, based on the relation between IMV and the collateral vessel. Type A and B in which either the collateral vessel crosses or runs close to the IMV with incidence of 43.3% and 13.3%, respectively, whereas type C is present in 43.3%. There was no definitive relation between the artery and vein. No intra or postoperative ischemic events were reported.

CONCLUSION

During IMV ligation, inadvertent ligation of Arc of Riolan or meandering mesenteric artery around the IMV root "in type A&B" might result in compromised blood supply to the left colon, congestion, ischemia and different level of colitis or anastomotic dehiscence. Therefore, careful dissection and skeletonization at the IMV root "before ligation if necessary" is mandatory to preserve the collateral vessel for the watershed area and to avoid further injury.

High ligation of the inferior mesenteric artery in rectal cancer surgery

In rectal cancer surgery, it is unclear whether the inferior mesenteric artery (IMA) should be ligated as high as possible, at its origin, or low, below the origin of the left colic artery. We reviewed all relevant articles identified from MEDLINE databases and found that despite a trend of improved survival among patients who underwent high ligation, there is no conclusive evidence to support this. High ligation of the IMA is beneficial in that it allows for en bloc dissection of the node metastases at and around the origin of the IMA, while enabling anastomosis to be performed in the pelvis, without tension, at the time of low anterior resection. High ligation of the IMA does not represent a source of increased anastomotic leak in rectal cancer surgery and postoperative quality of life is improved by preserving the hypogastric nerve without compromising the radicality of the operation. More importantly, high ligation of the IMA improves node harvest, enabling accurate tumor staging. Although the prognosis of patients with node metastases at and around the origin of the IMA is poor, the survival rate of patients with rectal cancer may be improved by performing high ligation of the IMA combined with neoadjuvant and adjuvant therapy.

High tie versus low tie of the inferior mesenteric artery in colorectal cancer: a RCT is needed

Nowadays left colon and rectal cancer treatment has been well standardized in both open and laparoscopy. Nevertheless, the level of the ligation of the inferior mesenteric artery (IMA), at the origin from the aorta (high tie) or below the origin of the left colic artery (low tie), is still debated. The objective of the systematic review is to evaluate the current scientific evidence of high versus low tie of the IMA in colorectal cancer surgery. The outcomes considered were overall 30-days postoperative morbidity, overall 30-days postoperative mortality, anastomotic leakage, 5-years survival rate, and overall recurrence rate. A total of 8.666 patients were included in our analysis, 4.281 forming the group undergoing high tie versus 4.385 patients undergoing low tie. Neither the high tie nor the low tie strategy showed an evidence based success, as no statistically significant differences were identified for all outcomes measured. Future high powered and well designed randomized clinical trials are needed to draw definitive conclusion on this dilemma.

Colonic ischemia following surgery for sigmoid colon and rectal cancer: a study of 10 cases and a review of the literature

PURPOSE

Colonic ischemia following colorectal surgery is an unusual and serious complication. As it has been reported that the incidence of colonic ischemia was higher after laparoscopic surgery, the aim of this report was to document the clinical features of postoperative colonic ischemia following colorectal surgery.

METHODS

Among 1,201 surgeries for sigmoid colon and rectal cancer by a single surgeon from 2006 to 2010, 10 cases of postoperative colonic ischemia were retrospectively identified (0.83%). IMA high ligation was routinely made in all surgeries. The clinical findings and laboratory data of these 10 cases were evaluated.

RESULTS

Of the 10 patients, 9 were male and 1 was female. The mean age was 66.9 years old. The mean BMI was 23.3. Three patients (30%) had a cardiovascular disease other than hypertension. Eight patients (80%) underwent laparoscopic surgery and two patients (20%) underwent open surgery. Intraoperative bleeding occurred in five patients (50%, mean 435 ml). The average day for occurrence of postoperative colonic ischemia was on the 5th day (range 2nd-10th day). A consistent postoperative fever was found in eight patients (80%). Mortality due to postoperative colonic ischemia was 10%.

CONCLUSIONS

Postoperative colonic ischemia may be considered one of the more important complications of colorectal resection.

Prospective randomized trial for determination of optimum size of side limb in low anterior resection with side-to-end anastomosis for rectal carcinoma

PURPOSE

Functional outcome after low anterior resection with side-to-end anastomosis is comparable with that after a colonic J-pouch construction. The optimum size of the side limb has yet to be determined. This prospective randomized trial compared a 3-cm (short) and 6-cm (long) side limb.

METHODS

Forty-four patients with a mid or low rectal cancer undergoing low anterior resection were randomly assigned to each group. Physiologic and clinical assessments were performed preoperatively and at 3, 6, and 12 months after ileostomy closure. Defecography was performed at six months after ileostomy closure.

RESULTS

Twenty patients in each group completed the study. Among them, one patient with a short limb and two others with a long limb developed leakage. Sphincter function and reservoir function were similar between the groups. Bowel function or incontinence scoring was similar between the groups. The incidence of incomplete evacuation assessed by defecography in the long limb group was significantly greater than in the short limb group (13/20 long and 5/20 short, P = 0.025). One patient in the long limb group experienced fecal impaction.

CONCLUSION

The study showed similar clinical results in patients with either a short limb or a long limb but seemed to be underpowered. A long limb may be associated with fecal impaction in patients undergoing low anterior resection with side-to-end anastomosis.

Level of arterial ligation in rectal cancer surgery: low tie preferred over high tie. A review

Consensus does not exist on the level of arterial ligation in rectal cancer surgery. From oncologic considerations, many surgeons apply high tie arterial ligation (level of inferior mesenteric artery). Other strategies include ligation at the level of the superior rectal artery, just caudally to the origin of the left colic artery (low tie), and ligation at a level without any intraoperative definition of the inferior mesenteric or superior rectal arteries. Publications concerning the level of ligation in rectal cancer surgery were systematically reviewed. Twenty-three articles that evaluated oncologic outcome (n = 14), anastomotic circulation (n = 5), autonomous innervation (n = 5), and tension on the anastomosis/anastomotic leakage (n = 2) matched our selection criteria and were systematically reviewed. There is insufficient evidence to support high tie as the technique of choice. Furthermore, high tie has been proven to decrease perfusion and innervation of the proximal limb. It is concluded that neither the high tie strategy nor the low tie strategy is evidence based and that low tie is anatomically less invasive with respect to circulation and autonomous innervation of the proximal limb of anastomosis. As a consequence, in rectal cancer surgery low tie should be the preferred method.

Applied vascular anatomy of the colon and rectum: clinical implications for the surgical oncologist

Surgery remains the most radical method of treatment of many solid tumors, including colorectal cancer; in these tumors, surgery is the only method that can offer the chance of cure. To avoid early postoperative morbidity (mainly, anastomotic leak) and to achieve good long-term results (low incidence of tumor recurrence, long overall and disease-free survival, and optimal quality of life), the surgeon should have an in-depth knowledge of vascular anatomy of the colon and rectum. This essential requirement is based on the fact that the actual course followed by lymph fluid drainage from any part of the colon/rectum is determined by its blood supply; therefore, the extent of resection for colorectal cancer follows the principles of blood supply and lymphatic drainage. Knowledge of the colorectal vascular anatomy and its variations is of vital importance in the planning of radical surgical treatment and in appropriately performing colorectal resections, particularly in the patient who underwent in the past colectomy or aortic surgery that has changed the usual pattern of collateral blood supply to the colon. This review summarizes currently available data regarding vascular anatomy of the colon and rectum, from a surgical perspective.

[Arterial anatomy of the sigmoid colon useful for colon take down techniques]

BACKGROUND

An anatomic study about the arterial vascularization of the sigmoid was performed in order to obtain guidelines for the surgical treatment of rectal carcinoma.

AIM

In the proposed technique, the sigmoid is brought down to the perineum, after radical anal-rectal resection, including sphincterectomy.

MATERIAL AND METHODS

Thirty-three anatomical pieces were obtained through in situ dissection of formolized corpses (22 were male and 11 female). Turpentine solution, red marking, polyvinyl chloride were the materials used for preparation after catheterization of the inferior mesenteric artery.

RESULTS

The inferior mesenteric artery originated in most cases from the left side of the abdominal aorta, approximately 4.3 cm fromits bifurcation point; the left colonic artery, in 25 cases, originated straight from the inferior mesenteric artery below the left colonic artery, after which the sigmoid would be brought down to the perineum.

CONCLUSION

Knowledge about arterial vascularization of the sigmoid could be helpful in the surgical management of rectal cancer.

Effect of high and intermediate ligation on survival and recurrence rates following curative resection of colorectal cancer

PURPOSE

How wide excision of the regional mesenteric lymphatic drainage influences survival and recurrence rates following curative resection of colorectal cancers needs to be more clearly defined.

METHODS

A series of 2,409 consecutive patients undergoing curative resections with detailed descriptions of the operative procedure and the lymphatic drainage in the surgical specimens provided a unique database to provide meaningful comparisons between high and intermediate level ligation.

RESULTS

High ligation made a statistically significant difference in the death rate from recurrent cancer in patients with Dukes B, AC, and C1 cancers. Based on cancer-related deaths, the probability of five-year survival rate increased with high ligation from 73.9 to 84 percent in patients with Dukes B colon cancers and from 49.0 to 58.6 percent in patients with Dukes C1 colon cancers. In patients with Dukes AC cancers, high ligation increased the five-year survival rate from 64.9 to 80.4 percent. In patients with Dukes C cancers with involved middle level lymph nodes, the five-year survival rate increased from 20.5 to 33 percent and the death rate from recurrent cancer fell from 77 to 59 percent with high ligation. In patients with Dukes AC cancers with four or less involved nodes, the five-year survival rate was increased by high ligation from 50 to 78.6 percent in the colon and from 40 to 71.4 percent in the rectum. When more than four lymph nodes were involved, the survival rate was unaffected by the level of ligation. Although high ligation reduced distant recurrences, its greatest effect was observed in the incidence of local and suture line recurrence. The five-year local recurrence rate in patients with Dukes B who were managed by high ligation was 11.4 percent compared with 18.7 percent with intermediate ligation. In patients with Dukes C cancer, the local recurrence rate was 20.8 percent five years following high ligation compared with 30.7 percent for intermediate ligation. In patients with Dukes B cancer who were undergoing curative resections, the incidence of suture line recurrence was 3.9 percent following high ligation compared with 5.5 percent following intermediate ligation. In patients with Dukes C cancer, the incidence of suture line recurrence was 6.9 percent with high ligation and 11.4 percent with intermediate ligation.

CONCLUSION

In certain stages of colorectal cancer, the more extensive resection of mesenteric lymphatic drainage associated with high ligation appears to increase the survival rate and reduce the recurrence rate following curative resections.

Rectal necrosis following anterior resection of the rectum

Acute ischaemic colitis is a well recognized complication following abdominal surgery. It may occur spontaneously in older patients and is probably due to diffuse or localized obliterative arterial disease. In contrast, acute ischaemic proctitis is a rare clinical problem. It is caused by an acute surgical or thromboembolic interruption of the major blood supply and or collateral circulation of the rectum. Minor ischaemia may result in superficial mucosal ulceration whereas a major ischaemic episode will result in rectal necrosis with perforation. Acute rectal necrosis has not been reported as a complication following anterior resection of the rectum. This paper details a patient who developed necrosis of the rectum and the anal canal following anterior resection of the rectum for cancer of the recto-sigmoid junction.

High tie of the inferior mesenteric artery in distal colorectal resections--a safe vascular procedure

Division of the inferior mesenteric artery flush with the aorta (high tie) allows a tension-free anastomosis in distal colorectal resections but may also diminish the blood supply. Tissue oxygen tension was measured proximal to the resection margin before and after either low or high division of the inferior mesenteric artery in 62 patients undergoing elective colorectal resections. Oxygenation was maintained or improved when the transverse (median change after vs before resection for low tie +9 mmHg (P < 0.05), high tie +8 mmHg (P = 0.3)) and descending colon (low tie +7 mmHg (p < 0.01), high tie +1 mmHg (p = 0.67)) were used for the anastomosis but diminished for sigmoid anastomoses (low tie -4 mmHg (P = 0.42), high tie -9 mmHg (P < 0.05)). Change in oxygenation was significantly affected by location of proximal resection site but not by choice of high or low tie. These results suggest that the marginal artery provides a more than adequate vascular supply to the transverse and descending colon, but that the sigmoid colon is not suitable for anastomosis. We conclude that the sigmoid colon be sacrificed and there should be no hesitation in performing a high tie to avoid tension in low pelvic anastomoses.

Leakage from stapled low anastomosis after total mesorectal excision for carcinoma of the rectum

Over 14 years 276 patients with rectal cancer underwent surgery; 219 who underwent low anterior resection of the rectum with total mesorectal excision were studied. There were 24 (11.0 per cent) major anastomotic leaks associated with peritonitis or a pelvic collection and 14 (6.4 per cent) minor leaks that were asymptomatic and detected by contrast enema. All major leaks occurred at an anastomotic height of less than 6 cm (P = 0.08). The abdominoperineal excision rate was 9.1 per cent. Major leaks were associated with failure to defunction in 11 of 62 patients and with a defunctioning colostomy in 13 of 157 (P = 0.03). Of the 24 patients with major leaks seven developed peritonitis, one with a defunctioned anastomosis (P = 0.002), and three died (P = 0.02). Use of the sigmoid colon led to major leakage in seven of 32 patients compared with 17 of 187 when the splenic flexure was employed (P = 0.05). There was no increase in the local recurrence rate but only nine patients with major leakage and a temporary stoma have had these closed. Key technical factors include: a clean dry pelvic cavity, pulsatile colonic blood supply, suction drainage started during closure and mobilization of ample tissue to fill the pelvic space.

Surgical anatomy of the arterial blood-supply of the human rectum

One of the factors possibly responsible for leakage at a colo-rectal anastomosis is a deficient blood-supply. The rectal circulation was studied in 30 cadavers by injection of colloidal barium sulfate with colored gelatin into the hypogastric and inferior mesenteric arteries. It was noted that there was uniformity of supply to the wall of the organ; the blood-supply derived from the hypogastric arteries in subjects over 50 years of age was minor; the predominant blood-supply was derived from the superior rectal artery. These findings suggest that the hypogastric arteries usually provide only a minor supply in persons over 50 years of age and that obstruction of the inferior mesenteric artery associated with the impaired blood-supply inherent in the rectal dissection must be included in the factors responsible for leakage at the colorectal anastomosis.

Lymph drainage from the upper and middle third of the rectum as demonstrated by 198 Au

Extensive lymph node dissections have been performed in an attempt to increase survival after abdomino-perineal excision or anterior resection of the rectum for carcinoma. The lymph drainage from the upper and middle third of the rectum was demonstrated by means of 198Au which was injected into the submucosa. Less than one percent was drained to pelvic lymph nodes, giving little support for pelvic lymph node dissection for carcinoma in the upper and middle third of the rectum.

Ischaemic colitis and abdomino-perineal excision of the rectum

Two patients are presented in whom ischaemic colitis followed some years after abdomino-perineal excision of the rectum for carcinoma. The first patient was a young man without evidence of arterial disease and the second patient suffered from auricular fibrillation, thought to be due to ischaemic heart disease. Ligation of the inferior mesenteric artery in the operation of abdomino-perineal excision of the rectum may reduce the blood flow through the marginal artery of Drummond rendering the remaining colon more liable to ischaemic damage. Patients who pass bright blood through a colostomy following abdomino-perineal excision of the rectum for carcinoma may have ischaemic colitis rather than a recurrence of the neoplasm.