Actuality of Colo-Anal Anastomosis

(1)

Definition

The definition of colo-anal anastomosis is still under debate. This argument is caused by the difference between the surgical anal canal (included between the anal margin and the levator plane) and the anatomic anal canal (between the anal margin and the dentate line). According to some surgeons, therefore, the excision of the rectum up to the levator plane with anastomosis performed on the surgical anal canal or immediately above it is considered colo-anal anastomosis. Others prefer a more rigor- ous definition, considering as colo-anal anastomosis a suture at the dentate line and referring to the former as a low or ultra-low colorectal anastomosis [1, 2].

Indications

The indication of a colo-anal anastomosis depends on tumour localisation, locoregional extension, anal sphincter function, the patient’s morphology and the surgeon’s experience [3–5].

Tumour Localisation

In tumours reaching the anal canal, or located less than 1 cm from the sphincter, abdomino-perineal resection (APR) is often the only curative surgery which can be realised, with the exception of some small tumours which are conservatively treatable:

local excision or proctectomy with intersphincteric resection. In the case of tumours located above 2 cm from the ano-rectal junction, it is almost always possible to preserve the anal sphincter with an onco- logically correct exeresis. In the case of tumours sited between1 and 2 cm from the anal canal, to achieve a proper distal clearance, we must resort to an intersphincteric resection. For tumours whose lower pole is less than 5 cm from the anal verge, a distal resection margin of 2 cm is enough [6], as long as a com-

plete exeresis of the mesorectum is performed which caudally ends 2–3 cm from the levator plane.

After Heald et al’s basic research on total mesorectal excision (TME) [7, 8] the distal section and anastomosis are performed, therefore, behind the anal canal, making the techniques of low, ultra-low and colo-anal anastomosis more routinary. The colorec- tal anastomosis is defined as low if the rectal stump is over2 cm long and ultra-low if it is less than 2 cm. If a total proctectomy with TME is necessary, this will be followed by a manual or mechanic colo-anal anas- tomosis.

Locoregional Extension

External sphincter infiltration represents the only absolute indication of APR, whereas internal sphincter infiltration may be treated with an intersphincteric resection, giving good functional and oncologi- cal results [9].

The existence of an anatomic and functional divi- sion between the puborectalis muscle and external anal sphincter allows, in limited experiences, excision of the rectum and puborectalis, preserving the external sphincter [10]. At the same distance from the rectum, a small sized tumour may be treated by conservative exeresis, whereas an APR is advisable to treat more extended cancer. This is not for reasons of local invasion, as there is no study showing a correla- tion between tumour volume and sphincter infiltration, but mainly for technical reasons of local and nervous dissection.

Preoperative radiotherapeutic overdosage may equally lead to avoidance of a colo-anal anastomosis.

Anal Sphincter Functional Conditions

Before considering colo-anal anastomosis, sphincter function must be assessed. A detailed continence his- tory and physical examination by an experienced surgeon are probably the most predictive evaluations

Gian Andrea Binda, Alberto Serventi

(2)

of post-operative function [11]. An abdominal colostomy is preferable to a perineal colostomy in cases where sphincter function is impaired.

Patient’s Morphology

The technical difficulties met during rectal surgery vary considerably depending on the patient’s morphology. The association of a considerable obesity and of a narrow and deep pelvis may be of hindrance to the technical realisation of a low or ultra-low anastomosis and make it necessary to perform a colo-anal anastomosis with perineal approach.

Surgical Technique

The abdominal part of the procedure implies a mobilisation of the left colon as in low and ultra-low colorectal anastomosis, both with laparoscopic and laparotomic access, and includes the high ligation of the mesenteric vessels, the mobilisation of the splenic fissure and rectum isolation up to the levator plane.

Anastomosis may be performed with different techniques depending on the site of the tumour’s lower pole and its degree of invasiveness, the patient’s morphology, the surgeon’s experience and limitations of flexion of the lower limbs.

Anastomosis Techniques

Handsewn Colo-Anal Anastomosis with Mucosectomy (Fig. 1)

This technique, described by Parks in 1982 [12, 13], is performed with a perineal approach. Once the anal canal has been exposed with a Lone Star® type retrac- tor, rectal mucosa is infiltrated with an adrenaline solution, favouring dissection and haemostasis.

Mucosectomy is then performed starting a few mil- limetres above the dentate line up to the apex of the rectal stump.

The anastomosis is then sutured between the colon or the apex of the colonic reservoir, pulled down to the rectal muscular cuff, and the anal canal with slow absorption stitches [14].

Colo-Anal Mechanical Anastomosis (Fig. 2)

The rectum is sectioned with a mechanical linear stapler at levator muscle level or lower after beginning dissection between the external and internal sphincters. Anastomosis is performed with a circular sta-

pler inserted with a trans-anal approach according to the technique described by Knight and Griffen [15].

The further rectal section determined by circular stapler in some cases may move the anastomosis level to the dentate line realising a “real” colo-anal anastomosis. The functional results improve by associating a colonic reservoir with anastomosis [16].

Fig. 1a, b. Park’s colo-anal anastomosis b

a

(3)

Colo-Anal Anastomosis with Rectal Stump Eversion (Fig. 3) This technique was described by Hautefeuille et al.

[17]. The rectal stump, once it has been sutured, is eversed through the anus and sectioned a few mil- limetres above the dentate line. The colic stump or the reservoir are then pulled down through the anus and the anastomosis is then sutured as before.

In order to allow the overturning of the rectal stump it is necessary to perform the rectum dissection, during abdominal time, as distal as possible.

Bowel function is said to be good [18].

Intersphincteric Colo-Anal Anastomosis

This technique, described by Schiessel et al. [19], includes the partial or total excision of the internal anal sphincter [20]. The approach is the same as Park’s technique, but the abdominal dissection is more extended, between the two sphincters to a macroscopically healthy area. With a trans-anal approach the intersphincteric plane must be detected and the section performed. A handsewn anastomosis is then fashioned. With this technique it is possible to treat, with a radical intent, tumours located between 1 and 2 cm from levator plane, T1 and even T2, although with a morbidity higher than the ordinary colo-anal anastomosis [21].

Fig. 2.Colo-anal mechanical anastomosis

Fig. 3a, b.Colo-anal anastomosis with rectal eversion

b a

(4)

Colo-Anal Anastomosis with a Trans-Sphincteric Approach This technique was described by Lazahortes et al.

[22] and combines the abdominal access with transsphincteric access according to Mason [23]. The patient is subjected to right lateral decubitus and the left leg is raised to reach a 45° angle. Abdominal dissection is performed as before through an incision to the patient’s left side.

Through an incision from the anal margin to the sacrum with coccyx resection. The external sphincter is sectioned to expose the rectum rear side, which is sectioned above the anal canal. Once the anastomosis between the apex of the cholic reservoir and the pectinate line is fashioned, the external sphincter is sutured.

Role of Defunctioning Stoma

The worst complication of colorectal surgery is rep- resented by an anastomotic leak and consequent pelvic infection; the incidence increases after ultra- low colorectal or colo-anal anastomosis, particularly when the exeresis of the mesorectum is complete, due probably to the devascularisation of the residual rectal stump [24].

The incidence of radiologic anastomotic leakage after total mesorectum excision and colo-anal anastomosis is about 16% vs. 8% in patients who did not undergo TME [25].

Protective stoma has the purpose of decreasing the consequences of an anastomotic leakage, which not only determines a pelvic peritonitis with a high degree of mortality (about 50%) but causes anorectal fibrotic stenosis [26]. In a recent study of about 2 000 patients, Eriksen et al. [27] presents an incidence of clinical dehiscence of 11.6%, showing that defunctioning stoma not only decreases the consequences of an anastomotic leakage but also reduces the risk of a leakage itself by 60%. Peeters et al. confirms this result and shows defunctioning stoma is related to a lower requirement of surgical reintervention [28]. For this reason a routine defunctioning ileostomy is advised and it may be electively closed after 4–6 weeks.

Results

Oncologic Results

The oncologic results of a colo-anal anastomosis with TME should be compared with the results achieved after anterior resection or APR with total mesorectum excision. The local recurrence ranges in different studies from 6 to 22% and 5-year survival ranges

from64 to 73% [29–32]. These results are comparable with those of the anterior resection and APR [33].

The published oncologic results of colo-anal anastomosis derive from retrospective studies including tumours with heterogeneous histology, different anastomotic techniques, various chemoradiotherapy regimes and different lengths of follow-up, making this comparison of limited significance.

Functional Results

A straight colo-anal anastomosis induces functional disorders in 80–87% of cases. The complete rectum excision implies the loss of its reservoir function determining the anterior resection syndrome described by Karanjia et al. in 1992 and characterised by an increased number of evacuations, difficulty with evacuation, incontinence to gas or liquid faeces, night leakage and tenesmus [34]. This syndrome improves significantly after one year [35], but in several studies with long-term follow up, considerable defecatory symptoms persisted. In a study published by Paty et al. [36] with a 4.3-year median follow-up, the most common symptoms patients complained of were: continence disorders (21% incontinence to gas, 23% minor leak and 5% significant leak), evacuation difficulties (32% fragmented evacuation) and 22% of patients reported 4 or more evacuations a day. The results were then classified as excellent for 28% of patients, good in 28% of patients, poor in 32% and very poor in 12% of cases.

To solve this complex mixture of anus and neorectum malfunctions the realisation of a colon reservoir was proposed [31] (Fig. 4), whose physiologic functions are the same as the iliac pouch made for ileo-anal anastomosis. A J-shaped pouch, initially 10–12 cm in size, determined serious evacuation problems [37]. Its size was then reduced to 5–6 cm in order to achieve a suitable reservoir without damag- ing the neorectum function [36]. Several prospective randomised studies proved how the functional results of the colo-anal anastomosis with J-shaped reservoir were much better than the ones made with straight colo-anal anastomosis [39–42]. In Ortiz et al.

study [43] on 30 patients, at 1-year follow-up, 38% of patients had normal continence with J-pouch vs.22%

of patients with straight anastomosis and the number of evacuations a day was respectively 2 and 4. Hall- bööck and Sjödahl [44], in a comparative study among patients with J-pouch and a control group, did not find any difference in terms of continence after1-year follow up; 20% referred evacuation difficulties and needed enemas. When the J-pouch is not feasible because mesentery is too thick or because its insertion into a narrow pelvis is too difficult, it is

(5)

then possible to realise another kind of cholic reservoir: the transverse coloplasty [45]. To perform such a reservoir an 8–10-cm long incision must be made on the colon, at about 4–5 cm from the distal extrem- ity, and be transversally sutured. A prospective randomised study proved that coloplasty gives functional results identical to the ones achieved with J-shaped reservoir [46]. A very recent study by Remzi et al.

[47] not only confirms the good functional results achieved by coloplasty, but it also shows a lower per- centage of anastomotic dehiscence.

Functional results comparable with those achieved with colo-anal astomosis with J-pouch were reported by Machado et al. [48] in a randomised per- spective study on 100 patients, performing latero-ter- minal colo-anal anastomosis.

Colo-anal anastomosis functional results after intersphincteric resection, with total or partial resection of the internal sphincter, are conflicting in the literature: Holzer et al. [49] reports very good functional results (88% of fully continent patients) whereas a more recent comparative study by Bretagnol et al. [50] shows a higher rate of incontinence and a worse quality of life compared to colo-anal anastomosis preserving internal anal sphincter.

References

1. Read TE, Kodner IJ (1999) Proctectomy and coloanal anastomosis for rectal cancer. Arch Surg 134:670–677 2. Aschele C (2004) Trattamento multidisciplinare inte-

grato del carcinoma del retto. GPAnet Editore, Milano 3. Abel ME, Rosen L, Kodner IJ et al (1993) Practice parameters for the treatment of rectal carcinoma. Dis Colon Rectum 36:989–1006

4. Porter GA, Soskolne CL, Yakimets WW et al (1998) Surgeon-related factors and outcome in rectal cancer.

Ann Surg 227:157–167

5. De Calan L, Gayet B, Bourlier P et al (2004) Chirurgie du cancer du rectum par laparotamie et par laparo- scopie. Encycl Méd Chir, Techniques chirurgicales.

Appareil Digestif 40-606, Elsevier, Paris

6. Pollet WG, Nicholls RJ (1983) The relationship between the extend of distal clearance and survival local recurrence rates after curative anterior resection for carcinoma of the rectum. Ann Surg 198:159–163 7. Heald RJ (1995) Total mesorectal excision is optimal

surgery for rectal cancer: a Scandinavian consensus.

Br J Surg 82:1297–1299

8. Heald RJ, Husband EM, Ryall RDH (1982) The mesorectum in rectal cancer surgery. The clue to pelvic recurrence? Br J Surg 69:613–616

9. Schumpelick V, Braun J (1996) Intersphincteric rectum resection with radial mesorectum excision and colo-anal anastomosis. Chirurg 67:110–120

10. Fucini C, Elbetti C, Petrolo A et al (2002) Excision of the levator muscles with external sphincter preserva- tion in the treatment of selected low T4 rectal cancers.

Dis Colon Rectum 45:1697–1705

11. Church JM, Saad R, Schroeder T et al (1993) Predicting the functional result of anastomoses to the anus: the paradox of preoperative anal resting pressure. Dis Colon Rectum 36:895–900

12. Parks A (1972) Transanal technique in low rectal anastomosis. Proc R Soc Med 65:975–976

13. Parks AG, Percy JP (1982) Resection and sutured colo- anal anastomosis for rectal carcinoma. Br J Surg 69:301–304

14. Penna C (1999) Proctectomie et anastomose coloanale, avec reservoir en J, pour cancer. J Chir 136:29–33

15. Knight CD, Griffen FD (1980) An improved technique for low anterior resection of the rectum using the EEA stapler. Surgery 88:710-714

16. Benoist S, Panis Y, Boelawski E et al (1997) Functional Fig. 4. Straight colo- anal anastomosis, J- pouch and coloplasty

(6)

outcome after coloanal versus low colorectal anastomosis for rectal carcinoma. J Am Coll Surg 185:114–119 17. Hautefeuille P, Valleur P, Perniceni T et al (1988) Functional and oncologic results after coloanal anastomosis for low rectal carcinoma. Ann Surg 207:61–64 18. Velez JP, Villavicencio RT, Schraut W et al (1999) Out- come analysis of external coloanal anastomosis. Am J Surg177:467–471

19. Schiessel R, Karner Hanusch J, Herbst F et al (1994) Intersphincteric resection for low rectal tumours. Br J Surg81:1376–1378

18. Kohler A, Athanasiadis S, Ommer A et al (2000) Long term results of low anterior resection with intersphincteric anastomosis in carcinoma of the lower one third of the rectum. Dis Colon Rectum 43:843–850 21. Rullier E, Zerbib F, Laurent C et al (1999) Intersphinc-

teric resection with excision of internal anal sphincter for conservative treatment of very low rectal cancer.

22. Lazahortes F, Fages P, Chiotasso P et al (1986) Syn- chronous abdominotranssphincteric resection of low rectal cancer: new technique for direct colo-anal anastomosis. Br J Surg 73:573–575

23. Mason AY (1977) Transsphincteric approach to rectal lesions. Surg Ann 9:171–194

24. Rullier E, Laurent C, Garrelon JL et al (1998) Risk factors for anastomotic leakage after resection of rectal cancer. Br J Surg 85:355–358

25. Carlsen E, Schlichting E, Guldvog I et al (1998) Effect of the introduction of total mesorectal excision for the treatment of rectal cancer. Br J Surg 85:526–529 26. Dehni N, Schlegel RD, Cunningham C et al (1998)

Influence of a defunctioning stoma on leakage rates after low colorectal anastomosis and colonic J–pouch- anal anastomosis. Br J Surg 85:1114–1117

27. Eriksen MT, Wibe A, Norstein J et al (2005) Norwegian Rectal Cancer Group. Anastomotic leakage following routine mesorectal excision for rectal cancer in a national cohort of patients. Colorectal Dis 7:51–57 28. Peeters KC, Tollenaar RA, Marijnen CA (2005) Risk

factors for anastomotic failure after total mesorectal excision of rectal cancer. Br J Surg 92:211–216.

29. Hautefeuille P, Valleur P, Perniceni T et al (1988) Functional and oncologic results after coloanal anastomosis for low rectal carcinoma. Ann Surg 207:61–64 30. Cavaliere F, Pemberton JH, Cosimelli M et al (1995) Coloanal anastomosis for rectal cancer. Long-term results at the Mayo and Cleveland Clinics. Dis Colon Rectum38: 807–812

31. Lazahortes F, Fages P, Chiotasso P et al (1986) Resec- tion of the rectum with construction of a colonic reservoir and colo–anal anastomosis for carcinoma of the rectum. Br J Surg 73:136–138

32. Paty PB, Enker EW, Cohen AM et al (1994) Treatment of rectal cancer by low anterior resection with coloanal anastomosis. Ann Surg 219:365–373

33. Dehni N, Cunningham C, Sarkis R et al (2000) Results of coloanal anastomosis for rectal cancer. Hepatogas- troenterology47:323–326

34. Karanjia ND, Schache DJ, Heald RJ (1992) Function of the distal rectum after low anterior resection for cancer. Br J Surg 79:114–116

35. Keighley MRB, Matheson D (1980) Functional results of rectal excision and endo-anal anastomosis. Br J Surg67:757–761

36. Paty PB, Enker WE, Cohen AM et al (1994) Long terms functional results of coloanale anastomosis for rectal cancer. Am J Surg 167:90–95

37. Hida JI, Yasutomi M, Fujimoto K et al (1996) Func- tional outcome after low anterior resection for rectal cancer using the colonic J-pouch. Prospective randomized study for determination of optimum pouch size. Dis Colon Rectum 39:986–991

38. Banerjee AK, Parc R (1996) Prediction of the optimum dimensions of colonic pouch reservoir. Dis Colon Rec- tum39:1293–1295

39. Hallbööck O, Pahlman L, Krog M et al (1996) Ran- domized comparison of straight and colonic j pouch anastomosis after low anterior resection. Ann Surg 224:58–65

40. Ho YM, Tan M, Seow-Choen F (1996) Prospective randomized controlled study of clinical function and anorectal physiology after low anterior resection:

comparison of straight and colonic J pouch anastomosis. Br J Surg 83:978–980

41. Lazahortes F, Chiotasso P, Gamagani RA et al (1997) Late clinical outcome in a randomized prospective comparison of colonic J–pouch and straight colo-anal anastomosis. Br J Surg 84:1449–1451

42. Seow-Choen F (1996) Colonic pouches in the treatment of low rectal cancer. Br J Surg 83:881–882 43. Ortiz H, De Miguel M, Armendariz P et al (1993)

Coloano anastomosis: are functional results with a colonic pouch better than with straight anastomosis?

44. Hallbööck O, Sjödahl R (1997) Comparison between the colon J pouch anal anastomosis and healthy rectum: clinical and physiologic function. Br J Surg 84:1437–1441

45. Z’gaggren, Maurer CA, Mettler D (1999) A novel colon pouch and its comparison with straight coloanal and colon J-pouch–anal anastomosis in the pig. Surgery 125:105–112

46. Furst A, Suttner S, Agha A et al (2003) Colonic J-pouch vs. coloplasty following resection of distal rectal cancer. Dis Colon Rectum 46:1161–1166

47. Remzi FH, Fazio VW, Gorgun E et al (2005) Quality of life, functional outcome, and complications of coloplasty pouch after low anterior resection. Dis Colon Rectum22 (Epub ahead of print)

48. Machado M, Nygren J, Goldman S et al (2003) Similar outcome after colonic pouch and side-to-end anastomosis in low anterior resection for rectal cancer: a prospective randomized trial. Ann Surg 238:214–220 49. Holzer B, Feil W, Holbling N et al (2002) Long term

results after intersphincteric resection of very low rectal cancer. Meeting of the European Association of Coloproctology, Erlangen, p 26

50. Bretagnol F, Rullier E, Laurent C et al (2004) Compar- ison of functional results and quality of life between intersphincteric resection and conventional coloanal anastomosis for low rectal cancer. Dis Colon Rectum 47:832–838