Anastomotic recurrence after sphincter-saving resection for rectal cancer. Length of distal clearance of the bowel

The Impact of Narrow and Infiltrated Distal Margin After Proctectomy for Rectal Cancer on Patients' Outcomes: a Systematic Review and Meta-analysis

Rectal cancer is a common tumor within a difficult anatomic constraint. Total mesorectal excision with longitudinal and circumferential free margins is considered imperative for good prognosis. In this article, the authors systematically reviewed all published literature with specific Mesh terms until the end of year 2019. Thereafter, retrieved articles were assessed using the Newcastle-Ottawa Scale and meta-analysis was conducted comparing local recurrence among 1-cm, 5-mm, and narrow (< 1-mm)/infiltrated margins. Thirty-nine articles were included in the study. Macroscopic distal margin < 1 cm carried a higher incidence of recurrence for those who did not receive neoadjuvant radiation, without affecting neither estimated overall nor disease-free survival. Less than 5-mm margin after radiation therapy is accepted oncologically. Infiltrated margins and narrow margins (< 1 mm) microscopically are associated with higher incidence of local recurrence and shorter overall and disease-free survival. Surgeons should aim at 1-cm safety margin in radiotherapy-naïve patients and microscopic free margin > 1 mm for those who received neoadjuvant therapy. The cost/benefit of reoperation for patients with infiltrated margins is still inadequately studied.

Long-term oncological outcomes of the sphincter preserving total mesorectal excision with varying distal resection margins

INTRODUCTION

A subcentimeter distal resection margin (DRM) appears to be acceptable for most patients, however, long-term follow up and specific subsets where DRM would influence recurrences have not been adequately investigated.

METHODS

A retrospective analysis of all sphincter-preserving resections for mid and low rectal cancers between July 2011 and May 2015 was performed. Extended total mesorectal excisions (TME) and patients with positive pathologic circumferential margins (CRM) were excluded.

RESULTS

Two hundred and thirty-six patients fit the inclusion criteria. DRM > 20 mm was obtained in 117 patients (49.6%), between 10 and 20 mm in 78 (33%) and <10 mm in 41 (17.4%) patients. Pathological DRM was positive in 4 patients (1.7%). Sixty-five recurrences occurred at a median follow up of 78.5 months. DRM did not influence any of the oncological outcomes. In a subset analysis of patients with poor pathological response to neoadjuvant radiation, that is, tumor regression grade > 3, DRM influenced disease-free survival (DFS) but not overall survival with a hazard ratio of 4.4 (p = 0.02). This was confirmed on multivariate regression analysis in this subgroup as well where pathological nodal status and DRM < 10 mm were independent predictors of DFS.

CONCLUSIONS

A subcentimeter DRM may be acceptable in most patients except those who have an inadequate response to neoadjuvant radiation.

Impact of Length of Distal Margin on Outcomes Following Sphincter Preserving Surgery for Middle and Lower Third Rectal Cancers

Outcomes of sphincter preserving surgery for distal rectal cancers improve with clear circumferential resection and distal resection margin. However, the extent of distal resection margin after a complete mesorectal excision is often a cause for debate. We evaluated the outcome of middle and lower third rectal cancer patients undergoing sphincter preservation with variable distal resection margin at our center. Patients with biopsy-proven rectal adenocarcinoma within 10 cm from anal verge undergoing sphincter preserving resections were included. Patients with positive circumferential resection margin were excluded. Patients were divided into three groups based on the extent of distal resection margin (< 6 mm, 6-10 mm, > 10 mm) and oncological outcomes were compared. The median age of 242 patients was 50 years and 44 (18.2%) were high-grade tumors. Preoperative chemoradiation was used in 185 (75.2%) patients. Median distal resection margin was 20 mm. Patients in < 10 mm group had a significantly higher proportion of lower third (68.3% vs 39.8%, p = 0.004) and chemoradiation-treated tumors (85.4 vs 74.6%, p = 0.001). A significantly higher percentage required an intersphincteric resection in the < 10 mm group (53.7% vs 14.4%, p = 0.0001). Significantly higher percentage tumors were pT3 in > 10 mm group (45.3% vs. 31.7%) (p = 0.05). The median follow-up was 23 months. There was no difference in the overall, loco-regional, and distant recurrence rates between the three groups. A subcentimeter distal resection margin does not influence loco-regional or distant recurrence rates following sphincter preserving surgery for middle and lower third rectal adenocarcinoma.

Impact of Distal Clearance Margin on Oncologic Outcome after Restorative Resection of the Rectum

There is considerable controversy about the distal clearance margin that needs to be maintained beyond the extent of a rectal tumor in order to reduce the risk of local recurrence. We investigated the rate of local recurrence, distant metastases and survival in 87 patients who had undergone radical restorative resection of the rectum for cancer and had been followed up for a median period of over 6 years, and we analyzed the statistical relation (log-rank test for trend) with the length of the distal margin. The distal margin length was divided into three categories: 1 cm, 2 cm, and ≥3 cm.

No significant correlation was found between the length of the distal clearance margin and the oncologic outcome. Taken together, our data suggest that if the resection line distally falls on healthy tissue, there is no need to resect additional rectum in order to achieve a better outcome.

Local recurrences at the anastomotic area are clonally related to the primary tumor in sporadic colorectal carcinoma

PURPOSE

Anastomotic recurrences (AR) occur in 2-10% of colorectal carcinoma cases after resection of primary tumor (PT). Currently, there are no molecular data investigating their genetic profile and multiple theories exist about their pathogenesis. The aim of our study was to compare the genomic profile of AR to that of the patients' corresponding matched PT and, when available, to a distant metastasis (DM).

EXPERIMENTAL DESIGN

Thirty-six tumors from 14 patients were genotyped using a capture-based, next-generation assay to define the mutational status of 341 cancer-associated genes. All patients had R0 resection of their PT and AR occurred 1.1-7.0 years following PT resection. A DM or a second AR was analyzed in 8 patients. All tumors were microsatellite stable except in one patient with Lynch syndrome.

RESULTS

A total of 254 somatic mutations were detected including 138 mutations in the microsatellite stable (MSS) cases. The most commonly mutated genes were APC, KRAS, TP53, PIK3CA, ATM and PIK3R1. In all patients with MSS tumors the AR and PT shared between 50-100% of mutations, including mutations in key driver genes, consistent with these tumors being clonally related. Genetic events private to DM were not detected in AR and phylogenetic analysis showed that ARs were more closely related to PT than DM. In the Lynch syndrome patient the PT and AR showed distinct somatic mutations consistent with independent primaries.

CONCLUSIONS

ARs are clonally related to PT in sporadic colorectal carcinomas and do not appear to represent seeding of the anastomotic site by distant metastases.

Positive detection of exfoliated colon cancer cells on linear stapler cartridges was associated with depth of tumor invasion and preoperative bowel preparation in colon cancer

BACKGROUND

The aim of this study was to investigate exfoliated cancer cells (ECCs) on linear stapler cartridges used for anastomotic sites in colon cancer.

METHODS

We prospectively analyzed ECCs on linear stapler cartridges used for anastomosis in 100 colon cancer patients who underwent colectomy. Having completed the functional end-to-end anastomosis, the linear stapler cartridges were irrigated with saline, which was collected for cytological examination and cytological diagnoses were made by board-certified pathologists based on Papanicolaou staining.

RESULTS

The detection rate of ECCs on the linear stapler cartridges was 20 %. Positive detection of ECCs was significantly associated with depth of tumor invasion (p = 0.012) and preoperative bowel preparation (p = 0.003). There were no marked differences between ECC-positive and ECC-negative groups in terms of the operation methods, tumor location, histopathological classification, and surgical margins.

CONCLUSIONS

Since ECCs were identified on the cartridge of the linear stapler used for anastomosis, preoperative mechanical bowel preparation using polyethylene glycol solution and cleansing at anastomotic sites using tumoricidal agents before anastomosis may be necessary to decrease ECCs in advanced colon cancer.

Positive detection of exfoliated colon cancer cells on linear stapler cartridges was associated with depth of tumor invasion and preoperative bowel preparation in colon cancer

Background

The aim of this study was to investigate exfoliated cancer cells (ECCs) on linear stapler cartridges used for anastomotic sites in colon cancer.

Methods

We prospectively analyzed ECCs on linear stapler cartridges used for anastomosis in 100 colon cancer patients who underwent colectomy. Having completed the functional end-to-end anastomosis, the linear stapler cartridges were irrigated with saline, which was collected for cytological examination and cytological diagnoses were made by board-certified pathologists based on Papanicolaou staining.

Results

The detection rate of ECCs on the linear stapler cartridges was 20 %. Positive detection of ECCs was significantly associated with depth of tumor invasion (p = 0.012) and preoperative bowel preparation (p = 0.003). There were no marked differences between ECC-positive and ECC-negative groups in terms of the operation methods, tumor location, histopathological classification, and surgical margins.

Conclusions

Since ECCs were identified on the cartridge of the linear stapler used for anastomosis, preoperative mechanical bowel preparation using polyethylene glycol solution and cleansing at anastomotic sites using tumoricidal agents before anastomosis may be necessary to decrease ECCs in advanced colon cancer.

Mesorectal excision: Surgical anatomy of the rectum, mesorectum, and pelvic fascia and nerves and clinical relevance

Biologic behavior and management of rectal cancer differ significantly from that of colon cancer. The surgical treatment is challenging since the rectum has dual arterial blood supply and venous drainage, extensive lymphatic drainage and is located in a bony pelvic in close proximity to urogenital and neurovascular structures that are invested with intricate fascial covering. The rectum is encased by fatty lymphovascular tissue (mesorectum) that is surrounded by perirectal fascia that act as barrier to the spread of the cancer and constitute the surgical circumferential margin. Locoregional recurrence after rectal cancer surgery is influenced by tumor-related factors and adequacy of the resection. Local recurrence is associated with incomplete excision of circumferential margin, violation of perirectal fascia, transmesorectal dissection, presence of isolated deposits in the mesorectum and tumor in regional lymph nodes and incomplete lymph node clearance. Hence to eradicate the primary rectal tumor and control regional disease, the rectum, first area of lymph node drainage and surrounding tissue must be completely excised while maintaining an intact fascial envelope around the rectum and preserving surrounding structures. This is achieved with extrafascial dissection and removal of the entire mesorectum including the portion distal to the tumor (total mesorectal excision) within its enveloping fascia as an intact unit. Total mesorectal excision is the standard of care surgical treatment of mid and low rectal cancer and can be performed in conjunction with low anterior resection, abdominoperineal resection, extralevator abdominoperineal resection, and extraregional dissection. To accomplish such a resection, thorough knowledge of the surgical anatomy of the rectum and pelvic structures and fascial planes is paramount.

The Cause and Prevention of Anastomotic Recurrence following Colectomy: An Immunohistochemical Approach for Detecting Transforming Colonocytes

With the ability to identify the presence of transforming colonocytes in a field adjacent to an existing primary colon cancer, it is now possible to reduce if not eliminate one of the major causes leading to anastomotic tumor recurrence. In a review of those colectomy cases that presented post-surgery with anastomotic recurrence, we noted that mucosal abnormalities could readily be detected adjacent to the primary lesion. Such changes had gone unrecognized at the time of surgery, when standard histologic procedures were employed. By utilizing monoclonal antibodies (mAbs) that defined the presence of tumor immunogenic proteins, we were able to reexamine so-called normal biopsy sites adjacent to the tumor. Here, it was possible to demonstrate the presence of altered cellular activity in existing phenotypically normal appearing colonocytes that were in the process of transforming to malignancy.

Eight consecutive patients that had been admitted for evaluation and resection of an anastomotic recurrence post colectomy, were studied with regard to possible etiologic factors. The original margins incorporated into the anastomosis were re-examined by immunohistochemistry employing those monoclonal antibodies (mAbs) designed to target colon tumor antigen. This antigen had previously been shown to be expressed only in colon cancer and not in adjacent normal tissue. In addition, biopsies from margins of resection in five patients free of recurrence following colectomy were also studied along with colon specimens from 50 normal patients, non-demonstrating expression of tumor antigen in the normal appearing colonocytes.

In each of the patients who had presented with anastomotic recurrence, normal appearing colonocytes defined by light microscopy and found adjacent to the previously resected primary lesion, expressed tumor antigen. The antigen detected in these colonocytes proved to be identical to antigen expressed in the anastomotic recurrence giving credence to the concept that these normal appearing cells in proximity to the tumor were responsible for the regrowth of tumor in the suture line used to establish continuity of the bowel.

Based on the findings of this preliminary retrospective study it is felt that at the time of performing a colectomy for a malignant lesion of the bowel, that it is important that those normal appearing colonocytes adjacent to tumor be evaluated for expression of tumor associated antigen. Excluding such cells from an anastomosis, may help to assure that tumor recurrence will be minimized if not totally eliminated.

Distal dissection in total mesorectal excision, and preoperative chemoradiotherapy and lateral lymph node dissection for rectal cancer

The local recurrence rate after total mesorectal excision (TME) appears to be markedly lower than that after conventional operations. We reviewed all relevant articles identified from the MEDLINE databases and clarified the rationale for TME. It is clear that distal intramural spread is rare. Even when present, such spread is not likely to extend beyond 2 cm. Data with attention to mesorectal cancer deposits suggest that mesorectal clearance of at least 4-5 cm distal to the tumor should be sufficient. TME should be performed for most tumors of the mid- and lower rectum. This does not mean that the gut tube needs to be divided at the same level in every case. Dissection of the distal mesorectum off the gut tube can be performed, so the distal line of division of the bowel wall can be made at a minimum of 2 cm below the tumor if such a maneuver would ensure that the sphincters are preserved. In cases with cancer in the upper third of the rectum, the mesorectum and gut tube can safely be divided 5 cm below the tumor without jeopardizing the recurrence rates. Our findings indicate that TME is an essential treatment approach for rectal cancer, and lateral lymph node dissection and preoperative chemoradiotherapy are additional therapies that should be considered for advanced rectal cancer.

Altering the therapeutic paradigm towards a distal bowel margin of < 1 cm in patients with low-lying rectal cancer: a systematic review and commentary

AIM

The 1-cm rule of distal bowel clearance in patients with low-lying rectal cancer undergoing anterior resection is based mainly on pathological data showing distal intramural spread. Because clinical data are contradictory, a review that includes only cancers located ≤ 5 or ≤ 6 cm from the anal verge was carried out.

METHOD

A systematic review of the literature identified seven studies that presented results in relation to a margin of ≤ 1 cm (n = 293) vs > 1 cm (n = 315). In six studies, pre- or postoperative radiotherapy was implemented, and in one study patients were treated with surgery alone. Three studies, all implementing radiotherapy, reported results related to a margin of ≤ 5 mm (n = 51) vs > 5 mm (n = 125).

RESULTS

In none of the studies were the differences in local recurrence rate between the small and large margin groups statistically significant. The pooled analysis of six studies, in which patients received perioperative radiotherapy, showed a 1.2% [95% confidence interval (Cl) -4.5-7.0%] higher local recurrence rate in the ≤ 1 cm margin group compared with the > 1 cm margin group (P = 0.6). The corresponding figures for the ≤ 5 mm cut-off point were 0.5% (95% CI -7.6-8.7%, P = 0.9). The 5-year local recurrence rate in the only study in which radiotherapy had not been used was 8.6% higher in the ≤ 1 cm margin group compared with the > 1 cm margin group (P = 0.09).

CONCLUSION

Clinical evidence does not support the 1-cm rule in patients with low-lying rectal cancer undergoing pre- or postoperative radiotherapy.

Is the 1-cm rule of distal bowel resection margin in rectal cancer based on clinical evidence? A systematic review

Background

Distal intramural spread is present within 1 cm from visible tumor in a substantial proportion of patients. Therefore, ≥1 cm of distal bowel clearance is recommended as minimally acceptable. However, clinical results are contradictory in answering the question of whether this rule is valid. The aim of this review was to evaluate whether in patients undergoing anterior resection, a distal bowel gross margin of <1 cm jeopardizes oncologic safety.

Methods

A systematic review of the literature identified 17 studies showing results in relation to margins of approximately <1 cm (948 patients) versus >1 cm (4626 patients); five studies in relation to a margin of ≤5 mm (173 patients) versus >5 mm (1277 patients), and five studies showing results in a margin of ≤2 mm (73 patients). In most studies, pre- or postoperative radiation was provided.

Results

A multifactorial process was identified resulting in selection of favorable tumors for anterior resection with the short bowel margin and unfavorable tumors for abdominoperineal resection or for anterior resection with the long margin. In total, the local recurrence rate was 1.0% higher in the <1-cm margin group compared to the >1-cm margin group (95% confidence interval [CI] −0.6 to 2.7; P = 0.175). The corresponding figures for ≤5 mm cutoff point were 1.7% (95% CI −1.9 to 5.3; P = 0.375). The pooled local recurrence rate in patients having ≤2 mm margin was 2.7% (95% CI 0 to 6.4).

Conclusions

In the selected group of patients, <1 cm margin did not jeopardize oncologic safety.

Stapler access and visibility in the deep pelvis: A comparative human cadaver study between a computerized right angle linear cutter versus a curved cutting stapler

Purpose

Distal rectal stapling is often challenging because of limited space and visibility. We compared two stapling devices in the distal rectum in a cadaver study: the iDrive™ right angle linear cutter (RALC) (Covidien, New Haven, CT) and the CONTOUR^® curved cutter (CC) (Ethicon Endo-Surgery, Cincinnati, OH).

Methods

Twelve male cadavers underwent pelvic dissection by 4 surgeons. After rectal mobilization as in a total mesorectal excision, the staplers were applied to the rectum as deep as possible in both the coronal and sagittal positions. The distance from the pelvic floor was measured for each application. A questionnaire rated the visibility and access of the stapling devices. Measurements were taken between pelvic landmarks to see what anatomic factors hinder the placement of a distal rectal stapler.

Results

The median (range) distance of the stapler from the pelvic floor in the coronal position for the RALC was 1.0 cm (0-4.0) vs. 2.0 cm (0-5.0) for the CC, p = 0.003. In the sagittal position, the median distance was 1.6 cm (0-3.5) for the RALC and 3.3 cm (0-5.0) for the CC, p < 0.0001. The RALC scored better than the CC in respect to: 1. interference by the symphysis pubis, 2. number of stapler readjustments, 3. ease of placement in the pelvis, 4. impediment of visibility, 5. ability to hold and retain tissue, 6. visibility rating, and 7. access in the pelvis. A shorter distance between the tip of the coccyx and the pubic symphysis correlated with a longer distance of the stapler from the pelvic floor (p = 0.002).

Conclusions

The RALC is superior to the CC in terms of access, visibility, and ease of placement in the deep pelvis. This could provide important clinical benefit to both patient and surgeon during difficult rectal surgery.

Anatomy of the lateral ligaments of the rectum: A controversial point of view

The existence and composition of the lateral ligaments of the rectum (LLR) are still the subjects of anatomical confusion and surgical misconception up to now. Since Miles proposed abdominoperineal excision as radical surgery for rectal cancer, the identification by “hooking them on the finger” has been accepted by many surgeons with no doubt; clamping, dividing and ligating are considered to be essential procedures in mobilization of the rectum in many surgical textbooks. But in cadaveric studies, many anatomists could not find LLR described by the textbooks, and more and more surgeons also failed to find LLR during the proctectomy according to the principle of total mesorectal excision. The anatomy of LLR has diverse descriptions in literatures. According to our clinical observations, the traditional anatomical structures of LLR do exist; LLR are constant dense connective bundles which are located in either lateral side of the lower part of the rectum, run between rectal visceral fascia and pelvic parietal fascia above the levator ani, and covered by superior fascia of pelvic diaphragm. They are pathways of blood vessels and nerve fibers toward the rectum and lymphatic vessels from the lower rectum toward the iliac lymph nodes.

Adequate length of the distal resection margin in rectal cancer: from the oncological point of view

INTRODUCTION

The distal resection margin (DRM) has been considered an important factor for the oncological outcome of rectal cancer surgery. However, the optimal distal margins required to achieve safe oncological outcome remains to be controversial.

MATERIAL AND METHODS

More recently, as circumferential resection margin or mesorectal margin has been additionally reported to be more important factors predicting patient outcome than the distal mucosal margin, a re-evaluation of the impact of DRM on patient outcome is needed.

RESULTS

The extent of distal tumor spread is known to be influenced by a variety of factors such as tumor location, lymph node metastasis, and tumor size. DRM might affect survival more than a local recurrence. Because distal intramural tumor spread rarely exceeds 1 to 2 cm in most rectal cancers, and local control and survival do not seem to be compromised by shorter distal resection margins, the generally accepted practice is to aim for a 2-cm DRM. However, in the recent trend of curative resection after preoperative chemoradiotherapy, with an otherwise favorable tumor such as well-differentiated tumor and no lymph node metastasis, a DRM at < or =1 cm does not necessarily portend a poor prognosis. In cases with preoperative chemoradiotherapy, distal resection margins need to be evaluated individually.

DISCUSSION

It has been suggested that down-staging of low-lying rectal cancers after preoperative radiation might well include the pathological clearance of distal intramural microscopic spread. Moreover, the measurement of DRM varies with respective study, making it difficult to compare.

CONCLUSION

We need an applicable intraoperative method to accurately measure distal resection margin, enabling comparative outcome.

Adequacy of 1-cm distal margin after restorative rectal cancer resection with sharp mesorectal excision and preoperative combined-modality therapy

BACKGROUND

Preoperative combined-modality therapy (CMT) for rectal cancer allows a sphincter-sparing procedure in some individuals who would otherwise require an abdominoperineal resection. To further define the subset of rectal cancer patients suitable for this approach, we determined the adequacy of a distal margin of < or = 1 cm in patients with locally advanced rectal cancer requiring preoperative CMT.

METHODS

Ninety-four consecutive patients, status post curative low anterior resection for rectal cancer after preoperative CMT, were identified from the prospective Colorectal Service Database. Distal margin length, tumor grade, tumor-node-metastasis stage, presence of lymphovascular and perineural invasion, and tumor distance from the anal verge were examined for their effect on recurrence and survival. Median follow-up was 44 months.

RESULTS

Distal margin length ranged from.1 to 9.5 cm (median, 2.0 cm) and did not correlate with local recurrence (hazard ratio, 1.1; P =.34) or recurrence-free survival (hazard ratio, 1.1; P =.29) by univariate analysis. Kaplan-Meier estimates of recurrence-free survival and local recurrence at 3 years for the < or = 1 cm versus >1 cm and the < ore = 2 cm versus > 2 cm groups were not significantly different. Groups were well matched for other clinicopathologic variables.

CONCLUSIONS

Our data suggest that for patients with locally advanced rectal cancer undergoing resection and preoperative CMT, distal margins < or = 1 cm do not seem to compromise oncological outcome.

[Colonoscopic follow-up of patients undergoing curative resection of colorectal cancer]

AIM

To investigate the role of colonoscopy in the follow-up of patients undergoing curative resection of colorectal cancer.

MATERIAL AND METHODS

A prospective study was performed of 102 patients with colorectal cancer who underwent surgery with curative intention. Postoperative colonoscopic follow-up was a minimum of 5 years.

RESULTS

There were 62 males and 40 females. The mean duration of follow-up was 73.4 months. Synchronous polyps were found in 44.1% (114 in 45 patients) and metachronous polyps in 33.4% (64 in 34 patients). Synchronous carcinoma was detected in 7.8% (9 in 8 patients), metachronous carcinoma in 1.9% (2 in 2 patients) and suture recurrence in 4.9% (5 in 5 patients). Metachronous polyps developed in 55.5% of the patients with synchronous polyps and in only 15.8% of those with no synchronous polyps (p < 0.00005); the odds ratio was 6.67. Colonoscopy diagnosed 92 synchronous polyps and 64 metachronous polyps; of these, 34 were found to be significant(in 22 patients). Colonoscopy diagnosed 5 synchronous carcinomas; in 3 of these (polyps with non-invasive carcinoma) polypectomy constituted definitive therapy and in the remaining 2, curative resection was achieved. Colonoscopy diagnosed 2 stage C2 metachronous carcinomas at 63 and 94 months. Curative resection was achieved in both cases. Colonoscopic follow-up diagnosed 2 suture recurrences and resection was potentially curative.

CONCLUSIONS

Colonoscopy was found to play an essential role in 30% of the patients. The technique allowed the early diagnosis of synchronous carcinomas and curative treatment of metachronous carcinomas and demonstrated that the presence of synchronous polyps increases the risk of developing metachronous polyps.

Management of locally advanced rectal cancer

The treatment of rectal cancer typically involves a multidisciplinary approach. A minority of patients will have tumors that are full thickness, involve adjacent structures, or have metastatic disease to regional lymph nodes. The combination of adjuvant therapy and surgical resection is the mainstay of treatment for locally advanced carcinoma of the rectum. This article will review the role of adjuvant chemotherapy and radiotherapy in patients with high risk tumors. The operative considerations in advanced rectal cancers will be reviewed. In particular, the role of mesorectal excision and exenterative surgery will be discussed.

Contribution to the surgical anatomy of the ligaments of the rectum

PURPOSE

Many authors have discussed the presence and the importance of the lateral ligaments of the rectum. Our contribution aims at clarifying some aspects of surgical anatomy that help in the preservation of the urogenital functions and may influence the surgical practice.

METHODS

From 1994 to 1998 we examined 27 fresh cadavers and five embalmed pelves. We performed all dissections with a technique similar to that used for the surgical mobilization of the rectum.

RESULTS

The lateral ligaments of the rectum are trapezoid structures originating from mesorectum and are anchored to the endopelvic fascia; as lateral extensions of the mesorectum, they must be included in the surgical specimen. According to our results, three main structures can be recognized laterally to the rectum: 1) the lateral ligament, which does not contain important structures; 2) the inferior hypogastric plexus and the urogenital bundle; and 3) the lateral neurovascular pedicle of the rectum that comprises the nervi recti and the middle rectal artery, both running under the lateral ligament, although at different angles.

CONCLUSION

At the point of insertion into the endopelvic fascia, the lateral ligaments run close to the urogenital bundle. Nevertheless, the dissection at its attachment is safe if the urogenital bundle is kept under visual control.

Outcome analysis of external coloanal anastomosis

BACKGROUND

To evaluate the safety and efficacy of treating low-lying rectal lesions with resection and primary repair using a pull-through technique with rectal stump eversion and external coloanal anastomosis with immediate reintroduction into the pelvis.

METHODS

All coloanal anastomoses with the above technique on the Gastrointestinal Surgery Service at the University of Pittsburgh from March 1990 to September 1995 were evaluated.

RESULTS

Fifty-two patients underwent coloanal anastomoses with the above technique, and follow-up was available for 96% (50 of 52) of patients. Rectal lesions in the 50 patients included cancer (n = 34), rectal adenomas (n = 13), and other lesions (n = 3). Mean follow-up period was 29.6 +/- 21.8 months (28.5 months for patients with carcinoma). Fecal continence was normal or good in 88% (44 of 50) of patients. Moderate or complete incontinence was present in 12% (6 of 50) of patients. The local recurrence rate of rectal cancer was 0%. Morbidity occurred in 22% (11 of 50) of patients. Survival was 90% (45 of 50 patients).

CONCLUSIONS

Coloanal anastomosis with this technique provides effective treatment for low-lying malignant or benign rectal lesions and has an acceptable complication rate.

Improving the treatment of colorectal cancer: the role of EUS

The two most important factors for determining the risk of local failure and overall prognosis in colorectal carcinoma are nodal status and the depth of tumor penetration into or through the bowel wall. These features have traditionally been determined pathologically because the clinical-staging accuracy of other imaging modalities such as computed tomography (CT) has not proven sufficiently predictive of surgical staging. However, endorectal or endoscopic ultrasonography (EUS) can be used to preoperatively evaluate nodal involvement with an accuracy of up to 86% (median: 80%) and depth of tumor penetration through the bowel wall with an accuracy of up to 97% (median: 85%) for effective clinical staging. This high staging accuracy is useful in managing colorectal cancer. Through clinical evaluation of the initial stage of colorectal cancer with EUS, a patient's risk of disease recurrence can best be determined and patients stratified for the most appropriate treatment. EUS can be used to select patients with lesions that can be treated with local excision or sphincter-sparing surgery, often combined with radiation therapy, in situations otherwise requiring an abdominoperineal resection. EUS can also be used to preoperatively identify patients with locally advanced or unresectable disease. Chemoradiation can then be given preoperatively, when it appears to be better tolerated and more effective than postoperative treatment. Unresectable tumors can often be downstaged sufficiently to allow their excision. In resectable disease, EUS can also identify patients at high risk for recurrence who would benefit from adjuvant chemoirradiation. EUS for precise staging or for earlier diagnosis of recurrence will further improve the clinical outcome of patients with colorectal tumors as significant advances both in surgical techniques and in combined chemotherapy/radiotherapy continue to be made and applied selectively in a stage-dependent manner.

Model of implantation of tumor cells simulating recurrence in colonic anastomosis in mice

PURPOSE

Local recurrence after colorectal cancer surgery is usually perianastomotic. An experiment was designed to investigate whether free intraluminal cells can penetrate through a colonic anastomosis and thereby cause local recurrence.

METHODS

BALB/c and C57/BL mice underwent ascending colotomy followed by watertight anastomosis. Thereafter, CT-26 murine colon carcinoma cells were injected into the cecal lumen 2 cm proximal to the anastomosis of syngeneic BALB/c mice, whereas B-16 murine melanoma cells were injected in the same fashion into C57/BL mice. Control animals without anastomosis received similar injections. Animals were killed 24 hours, 72 hours, and 30 days after surgery and were checked for tumorigenesis.

RESULTS

Results of peritoneal fluid cytology were negative after 24 hours, whereas after 72 hours cancer cells were identified in the peritoneal fluid of 80 percent of mice with colotomy and anastomosis compared with 20 percent of control mice. Thirty days after surgery, 11.1 percent of the control BALB/c mice developed pericecal tumor growth, similar to the overall rate of murine melanoma in C57/BL. In mice with anastomoses, perianastomotic tumor growth was observed in 47.5 percent of BALB/c mice (P < 0.001) and was correlated with the number of injected cells. Tumor growth reached approximately 75 percent tumor take with high cell densities, whereas in C57/BL mice no difference was found between the experimental and control groups.

CONCLUSIONS

The findings suggest that free intraluminal cancer cells of colonic origin may penetrate through watertight anastomoses and implant on the anastomotic or peritoneal surface and initiate tumor growth. This anastomotic penetration is cell-mass dependent. The reported experimental model is simple, reproducible, and advantageous for studies of colonic anastomosis.

Short-term preoperative radiotherapy results in down-staging of rectal cancer: a study of 1316 patients

BACKGROUND AND PURPOSE

This study was undertaken to investigate down-staging effects after short-term, high-fractionated preoperative radiotherapy.

MATERIAL AND METHODS

The relationships between preoperative radiotherapy 25-25.5 Gy given over 5-7 days and clinical variables (sex, age, tumour level, metastatic disease, and tumour size) and the risk of lymph node metastases were examined in 1316 patients with rectal adenocarcinoma by uni-, and multivariate analyses.

RESULTS

Irradiated specimens contained smaller tumours (P < 0.00001) and nodal metastases were less common (P < 0.001). In a logistic regression model, tumour size in cm was positively related to the risk for nodal spread (odds ratio, OR = 1.14, 95% confidence limits, CL, of OR 1.08-1.22). In the same model, radiotherapy decreased the risk for nodal involvement (OR 0.73, 95% CL 0.58-0.92. This risk was particularly reduced when the time interval between start of radiotherapy and surgery equalled 10 days or more.

CONCLUSIONS

These results demonstrate a down-staging effect by a short course of preoperative radiotherapy which should be considered in the interpretation of radiotherapy trials and in the recruitment of patients for further postoperative adjuvant treatment.

Prospective analysis of the distal margin of clearance in anterior resection for rectal carcinoma

The distal resection margin measured in situ at operation, on the fresh specimen and on the fixed specimen was analysed prospectively in 55 consecutive patients undergoing anterior resection for carcinoma of the rectum. There was obvious contraction in length from the operative margin to the specimen margin and to the fixed margin. As measured by contraction coefficients, contraction was greater in more proximal tumours than in distal ones. Eight of 55 patients had microscopic intramural spread in the fixed distal margin and the maximum spread was 12 mm. Taking contraction of the fixed margin into account, the extrapolated microscopic spread in the operative margin ranged from 0 to 47 mm.

Survival and local recurrence after anterior resection and abdominoperineal excision for rectal cancer

The aim of this retrospective study is to compare the outcome of abdominoperineal excision (APE) and anterior resection (AR) for rectal cancer in 136 patients. Local recurrence rates and 5-year survival probabilities were estimated for the AR and APE group. Further comparisons were carried out between hand-sewn and stapled anastomoses after AR, and between patients after AR and APE for tumours 2 to 6 cm from the dentate line. Local recurrence after AR occurred in 14% and after APE in 10% of these cases. Five-year survival probabilities and local recurrence frequencies showed no statistically significant difference (P > 0.05). Local recurrence rates were 13.5% after hand-sewn anastomoses and 15% after the stapled procedure. No statistically significant difference was observed in the 5-year survival and recurrence rate (P > 0.05). Seventy-four of 136 patients had tumours located 2 to 6 cm from the dentata line. Local recurrence occurred in 21% after AR and 5% after APE, showing a statistically significant difference in frequency (P < 0.05). No significant difference was found in cumulative 5-year survival probabilities. APE for advanced low rectal cancer showed a significant reduction in local recurrences compared to AR.

Resection margin for squamous cell carcinoma of the esophagus

OBJECTIVE

The safe resection margin in esophagectomy for esophageal squamous cell carcinoma (SCC) was determined based on the extent of epithelial and subepithelial accessory lesions from the main lesions of esophageal SCC.

BACKGROUND

There have been many reports on the high incidence of a positive resection margin for esophageal cancer. Although there were some studies on the relationships of the proximal clearance to postoperative local recurrence, no pathologic study on the resection margin has been reported.

METHODS

Four hundred twenty specimens of a whole resected esophagus were examined histopathologically and the longitudinal length from the main lesion to the five types of accessory lesions was measured on microscopic slides.

RESULTS

Contiguous intraepithelial carcinoma existed in 69 (46%) of 150 sites of main lesions restricted to the mucosa or submucosa and subepithelial lesions existed in 131 (54%) of 245 sites and 82 (55%) of 150 sites of main lesions invading an adventitia and into neighboring structures, respectively. The risk of a positive resection margin due to subepithelial lesions was below 5% at 10 mm in the main lesion, restricted to the submucosa or the muscularis propria, and at 30 mm in the main lesion, invading the adventitia in the potentially curative operation cases.

CONCLUSION

These clearances of the resection margin, in which the risk of a positive resection margin is below 5%, are acceptable, although these clearances should only be accepted after the extent of epithelial accessory lesions is accurately determined by the Lugol's stain method.

Coloanal anastomosis for rectal cancer. Long-term results at the Mayo and Cleveland Clinics

PURPOSE

This study was designed to determine functional outcomes and rates of survival and recurrence of coloanal anastomosis in rectal cancer patients.

METHODS

Between 1981 and 1991, 117 patients underwent coloanal anastomosis. Fifteen percent of the patients had a J-pouch; the rest had a straight coloanal anastomosis. Thirty-eight percent had no diverting stoma. Median distance of the tumor from the anal verge was 6.7 cm.

RESULTS

Local recurrence rate was 7 percent. Five-year survival was fully 69 percent. Satisfactory fecal continence was achieved by 78 percent of patients; no J-pouch patient had frequent incontinence. Sixty-two percent of the patients had major (anastomotic leak = 18 percent) or minor complications; complications were not mitigated by a diverting stoma or worsened by adjuvant therapy.

CONCLUSION

Although coloanal anastomosis is associated with a high chance of complications, the long-term outcome, in terms of disease-free survival and satisfactory function, is excellent.

Pelvic resection of recurrent rectal cancer

OBJECTIVE

The authors describe their experience with pelvic resection of recurrent rectal cancer with emphasis on patient selection for curative intent based on known tumor risk factors.

SUMMARY BACKGROUND DATA

Pelvic recurrence is a formidable problem in 30% of patients who have undergone a curative resection of primary rectal cancer. Although radiation can reduce the development of local recurrence and can provide palliation to many patients with localized disease, it is not curative. The authors and others have used the technique of abdominal sacral resection (ABSR) with or without pelvic exenteration to resect pelvic recurrence and its musculoskeletal extensions in selected patients with satisfactory long-term survival.

METHODS

The technique of ABSR with or without pelvic exenteration or resection of pelvic viscera, which the authors have described previously, was used in 53 patients with recurrent rectal cancer--47 patients for curative intent and 6 for palliation. Previous surgeries were abdominal perineal resections (APRs) in 26 patients, anterior resections in 19 patients, and other procedures in 2 patients; original primary Dukes' stage was B in 52% and C in 48%. Almost all patients had been irradiated previously, generally in the 4000 to 5900 cGy range. Preoperative carcinoembryonic antigen (CEA) levels (before ABSR) were elevated (> 5 ng/mL) in 54%.

RESULTS

Postoperative morbidity was encountered in most patients. Mortality was 8.5% in the curative group. Long-term survival for 4 years was achieved in 14 of 43 patients (33%), and 10 patients were alive with an acceptable quality of life after 5 years. Patients who had previous anterior resections or whose preoperative CEA levels were less than 10 ng/mL had a survival rate of approximately 45%, whereas patients with previous APRs and preoperative CEA levels greater than 10 ng/mL had a survival rate of only 15% to 18%. Patients with bone marrow invasion, positive margins, or pelvic node metastases had a median survival of only 10 months.

CONCLUSIONS

Pelvic recurrence of rectal cancer can be resected safely with expectation of long-term survival of 33%. Patient selection based on known risk factors can identify patients most likely to benefit from resection and eliminate those who should be treated for palliation only.

Variables related to risk of recurrence in rectal cancer without lymph node metastasis

BACKGROUND

There has been recent interest in the use of local excision for rectal cancer under consideration of patient's quality of life. However, local excision of the primary tumor does not remove the areas of lymphatic spread. Therefore, the decision to use this procedure must be considered carefully.

METHODS

The authors retrospectively analyzed 142 patients who underwent radical resection of rectal cancer without lymph node metastasis in order to define the risk factors for recurrence. The macroscopic and microscopic pathological characteristics, immunohistochemical staining for p53, and DNA ploidy pattern of the primary tumor were examined as potential predictors of recurrence.

RESULTS

The rates for 5-year disease-free survival, local control, freedom from distant metastasis, and overall survival in these 142 patients were 87%, 93%, 93%, and 91%, respectively. Factors related to recurrence and prognosis included the depth of tumor invasion, vascular/lymphatic involvement, tumor differentiation, and tumor size. However, p53 staining and DNA ploidy pattern were not useful indicators.

CONCLUSIONS

Our findings suggest that adjunctive radiotherapy and chemotherapy should be considered for patients who have rectal cancer without lymph node metastasis in the following situations: tumor invasion of the serosa, vascular/lymphatic involvement, moderately differentiated adenocarcinoma, and lesions > 2 cm in diameter. Local excision should not be used in these situations, even if there are no lymph node metastases.

Lumboaortic and iliac lymphadenectomy: what is the role today?

PURPOSE

The aim of this study was to evaluate the roles of the lymphadenectomy in the surgical treatment of rectal cancer.

METHODS

On the basis of our experience of 252 curative operations for rectal cancer, we analyze survival and recurrence in relation to the lymph node involvement and to the level of the lymph nodes where the metastases are located. All patients underwent a lymphadenectomy with high ligation of the inferior mesenteric artery and removal of the lumboaortic lymph nodes from the left renal vein to the aortic bifurcation. Pelvic lymphadenectomy was performed in 16 cases.

RESULTS

Five-year survival was 70.6 percent in patients with no lymph node involvement, 68.2 percent in patients with pararectal lymph nodes N+, 25 percent in patients with involvement of intermediate lymph nodes, and 30 percent in patients with involvement of lumboaortic lymph nodes. In no case was there involvement of the hypogastric lymph nodes. On the basis of our experience and from results in the literature, we consider an upward extended lymphadenectomy with high ligation of the inferior mesenteric artery is warranted since it enables the tumor to be staged accurately and may lead to survival even in cases of advanced lymph node involvement.

Results of surgical treatment of nonhepatic recurrence of colorectal carcinoma

The sites of first recurrence of colorectal cancer include liver (more than 30%), lung and locoregional disease (20-25%), other intraabdominal sites (15-20%), and elsewhere (10%). Isolated locoregional disease accounts for 5-19% of colon recurrences and 7-33% of rectal recurrences. Between 7% and 20% of locally recurrent colorectal cancer can be resected with curative intent. Overall, complete resection of a localized recurrence yields a mean survival of 33-59 months, with long-term survival achieved in 30-50% of patients. Regional recurrence of rectal cancer may require abdominal-sacral resection for adequate margins, with 5-year survival of 18-24%. Early identification (by close monitoring) and accurate staging of recurrence are essential for potentially curative resection. Long-term survival depends on extent of recurrence and completeness of resection. Symptomatic recurrence to the ovaries that requires reoperation occurs in approximately 2% of patients; presentation usually is as part of a diffuse intraabdominal process, and resection is rarely curative. Isolated pulmonary metastases occur in 2-4% of patients experiencing disease recurrence; such tumors are resectable in half of the patients. After the tumors are surgically resected, long-term survival can be expected in 30-40% of patients, with prognosis variably associated with disease-free interval, number and size of lung metastases, and location and stage of the primary tumor. Newer techniques of postoperative monitoring after resection of the primary lesion, more sensitive preoperative and intraoperative staging of recurrences, and the use of intraoperative radiation therapy may increase surgical salvage of recurrent colorectal cancer.

Pelvic recurrence after surgical treatment of rectal and sigmoid cancer. A prospective clinical trial on 274 patients

The aim of this collaborative prospective study was to verify the incidence of pelvic recurrence (PR) after radical surgery for cancer of the rectum and sigmoid. Very low anterior resection (VLAR) was usually performed, with the aim of preserving anal function and obtaining the maximum of radicality by means of en bloc excision of the mesorectum. Between 1984 and 1987, 274 patients underwent curative surgery for rectal and sigmoid cancer, 230 (84%) of whom underwent anterior resection (AR) and 44 (16%) abdominoperineal resection (APR). Post-operative mortality was 2.5%. Follow-up ranged from 24 to 72 months (mean 37 m); 248 cases (90.5%) were included in the final prospective study. PR occurred in 41/248 cases (16%), within 24 months in 80% of cases. PR occurred in 15.8% (33/208) after AR and in 20% (8/40) after APR, p = NS. Nevertheless in middle and low rectal tumours at stage C the incidence of PR in patients who had VLAR was 34.5% (10/29) and 12% (3/25) in those who had APR (p < 0.05). PR rates in VLAR patients was 40% for stage C low rectal tumours and 54.5% for low rectal tumours at Astler Coller stage C2. The PR incidence for stage C1 tumours of the low rectum was zero after VLAR and APR, allowing the assumption that lymphnode metastases in non-penetrating tumours do not compromise the results when the mesorectum is completely excised. We can assume that the choice of VLAR as a substitute for APR whenever possible limits the comparison of their results.(ABSTRACT TRUNCATED AT 250 WORDS)

Adequate distal margin of resection for adenocarcinoma of the rectum

There are two questions in the surgical treatment of rectal cancer: (1) How far below a palpable rectal cancer should a surgeon cut in order to avoid cutting through cancer and, (2) Given that the surgeon has not cut through cancer, could the chance of subsequent recurrent rectal cancer have been reduced if an even greater length of bowel had been removed. For mobile tumors that are not poorly differentiated the answer to the first question is far enough in order to get a right-angled clamp on below the tumor that will not slip; the answer to the second question is no.

Results of intersphincteric resection of the rectum with direct coloanal anastomosis for rectal carcinoma

Between 1977 and 1987, 519 patients underwent operation for rectal carcinoma. Sixty-three patients underwent intersphincteric resection with direct coloanal anastomosis (CAA), and 77 had an abdominoperineal resection (APR). Curative surgery was achieved in 57 and 65 patients, respectively. Both groups were comparable regarding age, stage of tumors, and localization of tumors. During the mean period of 6.7 years (range: 3 to 13.6 years), all patients were examined according to a predefined follow-up plan. From those patients with curative surgery, 11% presented with pelvic recurrence and 33% with distant metastases after coloanal anastomosis; the rates of recurrence and distant metastases after APR were 17% and 35%, respectively. The corrected 5-year survival rates were 62% following CAA and 53% following APR. Eighty-five percent of the patients with CAA reported good functional results regarding anal continence. Our study demonstrates that the intersphincteric resection with CAA is a valuable surgical technique for rectal carcinoma with the benefit of preservation of continence. It is suitable for neoplasms with high- and medium-grade differentiation (G1 to G2) and a localization that allows a minimum distal clearence of 3 cm.

Endoscopic ultrasonography in colorectal diseases

Since new flexible high-frequency ultrasound endoscopes are now available, the use of this technique in colorectal disease has been determined. Its role in the preoperative staging of rectal cancer, and in follow-up after surgery has been established, but its use in cases of anal cancer and in non-neoplastic rectal diseases still has to be demonstrated more precisely.

Extended resection in the treatment of colorectal cancer

Between 1975 and 1990, 525 patients underwent resection of colorectal cancer in our unit. Of these, 38 had tumour invading adjacent structures and underwent an extended resection. Overall, there were 67 cases treated palliatively. Of these, three were in the group of 38 having an extended resection. When the groups of radical not extended (n = 423) and radical extended resections (n = 35) were compared, respective values for mortality (1.9% vs 0) and morbidity (12.8% vs 11.3%) were not different. Respective local recurrence rates (13% vs 26%) were significantly greater after extended resection. Five-year survival after extended resection was 30%, no different from the general survival rate for standard resections for T2-3 node-positive tumours. Extended resection is thus a safe and important approach for locally advanced tumours.

Regional mesenteric recurrence of colorectal cancer after anterior resection or left hemicolectomy: inadequate primary resection demonstrated by angiography of the remaining arterial supply

Inferior mesenteric angiography was carried out in 14 patients with locoregional recurrence following sphincter-saving resection of a colorectal primary tumour in the left hemicolon or rectum. The aim was to check the margins of clearance of the lymphatic drainage. All patients had been operated on electively and with curative intent. All patients had a biopsy-proven recurrence and 11 of the 14 patients (79%) showed residual arteries that should have been resected at primary surgery, and at laparotomy for the recurrence incomplete resection of the lymphatic drainage area was confirmed. In 6 patients the recurrence was resected, in 4 of them with no evidence of microscopic residual disease. From these findings it may be argued that the lymph nodes incompletely resected at primary operation may have been the origin of the locoregional recurrence. Angiography may detect this situation, and may be worthwhile when planning a reintervention.

Proctectomy and coloanal reconstruction for rectal cancer

There is increasing interest in the use of coloanal reconstruction following proctectomy for low rectal cancer. The authors review the surgical options for such sphincter-saving approaches, and report their pilot experience with eight patients receiving high-dose preoperative radiation with subsequent proctectomy and endoanal anastomosis. There were no anastomotic leaks.

Proposed distal margin for resection of rectal cancer

To determine the adequate distal margin, particularly from the point of extent of lymph node metastasis, 2,333 lymph nodes from 44 patients with rectal carcinoma were evaluated, using a clearing method. The tumors were divided into two growth patterns; infiltrative and localized. Lymph node metastasis was histo-pathologically examined with special attention focused on nodes on the distal side of the tumor. The intramural spread was also given attention. The proximal pararectal lymph nodes often contained malignant cells, whereas the distal ones were rarely involved, and if involved, they were present within 1 cm from the tumor. Pararectal lymph node metastasis and intramural spread were seen with a range of 1 cm and 0.5 cm, respectively, in the localized type and 1 cm and 2.1 cm, respectively in the infiltrative type. Based on these findings, the distal margin for surgical resection of rectal carcinoma is considered to be 2 cm for the localized type and 3 cm for the infiltrative type.

Endoluminal ultrasound for early detection of local recurrence of rectal cancer

The diagnostic potential of endoluminal (endorectal and endovaginal) ultrasound to detect asymptomatic resectable local recurrence after rectal cancer surgery has been assessed in 120 patients: 17 recurrences (14 per cent) were detected. The method showed 97 per cent accuracy, 94 per cent sensitivity and 98 per cent specificity; the positive predictive value was 85 per cent and the negative predictive value was 99 per cent. A longer follow-up is, however, necessary to confirm these results. Of the 17 patients with local recurrence, six were asymptomatic and underwent reoperative surgery. Of the other 11 patients with symptomatic recurrence, only two underwent reoperative surgery.

The detection and evaluation of locally recurrent rectal cancer with rectal endosonography

Eighty-five patients treated surgically for rectal cancer have been followed up by conventional clinical examination, sigmoidoscopy, and endosonography. Local recurrence was diagnosed in 22 patients. Nineteen of these had either sigmoidoscopic or digital evidence of recurrence and three were diagnosed solely by endosonography. In all cases endosonography gave additional information on which to base management decisions. Routine use of endosonography should allow the detection of early recurrence in a larger number of patients.

Analysis of recurrence following curative low anterior resection and stapled anastomoses for carcinoma of the middle third and lower rectum

In a series of 93 patients with middle and lower rectal cancer, who underwent potentially curative surgery by low anterior resection (LAR) with EEA stapled anastomosis or by abdominoperineal excision (APE) between January 1977 and December 1981, the incidence of recurrence and survival rate was compared. LAR with stapler was performed in 61 patients: 55 (90.2 percent) with tumors of the middle third and six (9.8 percent) for tumors of the lower third of the rectum. APE was performed in 32 patients: 13 (40.6 percent) with cancer of the midrectum and 19 (59.4 percent) of the lower rectum. Tumor site, Dukes' distribution, grade of malignancy, and extent of local spread were recorded. The tumor stages for LAR with stapler and for APE, respectively, were Dukes' A 7/1; Dukes' B 27/10; Dukes' C 25/18; Dukes' D 2/3. In a follow-up period of four years (range, 6 to 52 months) the overall recurrence rates were 20.4 percent in the LAR with stapled anastomosis group and 21 percent in the APE group. Local recurrence percentages were 9.8 percent after LAR and 14 percent after APE (P = N.S.). Distant recurrences were 12 percent and 14 percent, respectively. The four-year overall survival rates were 76.7 percent after LAR and 65.5 percent after APE (P = N.S.) The clinical and pathologic factors correlated with recurrence in low rectal carcinoma were reanalyzed and the controversial points of the surgical management for and against LAR with stapled anastomosis and APE were discussed. It is concluded that LAR with the EEA stapler can be carried out in the middle and lower rectum with the prospect of ultimate cure, when performed with proper technical skills in selected patients.

Anterior resection using the circular stapling instrument: a Singapore experience

The circular stapler was used for colorectal anastomosis in 38 patients (rectal carcinoma 37 cases, sigmoid diverticulitis one case). In Singapore Chinese patients, the most commonly used cartridge size was the EEA 28 mm and ILS 29 mm. The incidence of clinical anastomotic leakage in patients with complete resection rings was 10% (three leaks in 32 patients), leakage occurring only amongst the 24 patients who had resection of a tumour 6-9 cm from the anal verge. Significant, though easily dilatable, stenosis occurred in three patients (8%), and was associated with rectal membrane formation in two patients. Local recurrence, occurring in seven patients in a 0.5-3 year follow-up period was associated with Dukes' C disease; two recurrences occurred in four patients in whom the distal bowel clearance was less than 1.5 cm. The circular stapler facilitates sphincter conservation in mid-rectal cancer and its use in low anterior resection is justifiable when performed with a distal bowel clearance of 2 cm and complete excision of pararectal tissue above the pelvic floor muscles.