1. Colonic stenting: a bridge to surgery ?
Joint hospital surgical grand round
Fiona Ka Man Chan
Kwong Wah Hospital

2. Acute malignant colonic obstruction
Occur in 8% to 29% of all colorectal malignancies
70% are left sided
5 year survival in obstructed carcinoma of colon 20%
Right sided obstruction are dealt with by emergency right hemicolectomy with ileocolic anastomosis
No optimal treatment for left sided colonic obstruction
Poor prognosis in obstructive compared with non obstructive patients with OS 5 yr 20%
There were fewer Dukes' A tumours in those with complete obstruction (P less than 0.005) and greater numbers of advanced tumours (P less than ) compared with those without obstruction
The main reason for this is that emergency surgery for obstruction of the right colon carries the same mortality as that for elective surgery as shown in the Large Bowel
Cancer Project, right sided obstruction are dealt with by emergency
Deans et al. Br J Surg ; 81:1270–1276
Serpell et al. Br J Surg. 1989; 76:
Phillips et al. Br J Surg. 1985; 72: 296–302
Finan et al. Colorectal Disease. 2007;9:1-17

3. What are the options for obstructive left sided colonic cancer (OLCC) ?
40% will undergo one stage resection and anastomosis
Most frequently used is hartmanns procedure
The advocates of SC note the safety of ileocolic anastomoses, which eliminate possible metachronous tumors and treat possible synchronous tumors [12].
The main drawback is the increased surgical time, the scale of the surgery and the loss of physiological functions of the colon such as absorption and storage.
The advocates of IOCL also consider primary colocolic anastomoses to be safe, with morbidity (2-37%) and mortality rates (0-17%) [13] similar to those reported with the
Hartmann procedure (9-33% and 6-18%, respectively).
IOCL avoids the disadvantages of the reconstruction of the intestinal transit and thus has better survival rates than the Hartmann procedure
Until recently the use of colonic stenting for relieve of obstruction to allow definitive elective surgery at optimal conditions
Ansaloni et al. WSES guidelines 2010

4. Emergency surgery High morbidity 40-50% and mortality 15-20%
Primary resection and anastomosis carried a mortality rate of 10% , wound infection 25-60%, and high clinical leakage rate of 18% compared with 6% in elective surgery
High risk patients with poor general condition underlying tumour disease , dehydration and electrolyte imbalance .
Mortality 3.5% morbidity 23%
Tekkis et al. Ann Surg. 2004, 350:76-81
Deans et al. Br J Surg. 1994, 39:
Phillips et al. Br J Surg. 1985, 72: 296–302

5. Impact of stoma Emergency surgery resulted in high stoma rates
Stoma creation is associated with high complication of 34% and impaired quality of life
Up to 40% of stomas were not reversed
Stoma closure is associated with mortality of 7%, morbidity 37%, leakage 3%
34% of complication : ileostomies and colostomy; early and late; improper site, retraction, skin irritation, peristomal infection/hernia
Unable to reverse due to advanced age or comorbidity,
leading to higher health costs in terms of psychological well being, and reducing quality of life
Cost of stoma care shouldn’t be over looked, enterostomal supplies, lost of work, decrease QOL
Represents a significant burden on the enconomical and psychological well being
Park et al. Dis Colon Rectum. 1999; 42:1575–1580
Nugent et al. Dis Colon Rectum. 1999; ;42:1569
Deans et al. Br J Surg. 1994, 39:

6. Potential benefits of self expanding metallic stents (SEMS)
Increase one stage operation with resection and primary anastomosis
Decrease stoma rate
Decrease morbidity and mortality
Convert the procedure to an election condition
adequate resuscitation
bowel preparation
staging
optimization of comorbidities
neoadjuvant chemoradiotherapy
possibility of laparoscopic colectomy with primary anastomosis
single stage operation

7. Recent evidence
Recent RCTs demonstrates variability in their results from stenting against emergency syrgery.
ITT
Tan et al Br J Surg. 2012; 99: 469–476

8. 234 ppl 116 sems 118

9. Primary anastomosis
Overall successful primary anastomosis in favour of SEMS group
Significant difference in 1 stage operation with primary anastomosis in SEMS group 67% Vs 38% in emergency surgery group
This echoes with previous studies of Primary anastomosis 84.6% Vs 41.4% (martinez)
Converting an emergency procedure to an elective one thus creating optimal condition for susccessful primary anastomosis
Tan et al Br J Surg. 2012; 99: 469–476
Martinez et al. Dis Colon Rectum.2002; 45:401–406
Cheung et al. Arch Surg. 2009; 144:1127–1132

10. Stoma rates Overall stoma rates in favour of SEMS group
Decrease stoma requirement (7% Vs 43%) Targownik
Tan et al Br J Surg. 2012; 99: 469–476

11. Success rate
Technical success rate 92-96%, clinical % in previous systemic reviews on uncontrolled data
Drop in technical success rate of % and clinical success of 40-83% in recent randomized controlled trails
One trial terminated due to high rate of technical failure (53%)
Pirlet 40% technical and clincial success
Van hooft 70%
70% of complete obstruction rates compare with previous published data with 53.8% , in which degree of obstruction is considered one important factor for complications
Multicentered
Khot et al. Br J Surg. 2002; 89:1096–1102
Watt et al. Ann Surg. 2007; 246:24–30
Tan et al Br J Surg. 2012; 99: 469–476

12. Complications Overall complication rates 5.3-5.9% Mortality 0.5-1%
Early
Perforation 3-5%
Bleeding 0-5%
Misplacement
Late
Migration 11%
Reocclusion 10%
Erosion
Perforation: esp after balloon dilatation or laser cannalization 3-5% , 10% mortality rate
Migration 11%: small stent diameter, short length, cover stent, angulation, chemo/radiotherapy
Reocclusion: ingrowth, migration, fecal impaction, distortion
Perforation: death and tumour dissemniation
Tan: silent perforation 14%
Higher perforation rates in recent RCT : 13%-66% Van Hooft, chemo. Short interval between stenting and OT, patient with poor risk
Khot et al. Br J Surg. 2002; 89:1096–1102

13. Fracture
Migration

14. Perforation
One Dutch randomized controlled trial reported a high perforation risk up to 9%, up to 20% when silent perforations were included
Another also report perforation rate of 7% with silent perforation adding on to 35% perforation rate
Potential of tumour dissemination leading to compromise of oncological safety
No survival and local recurrence data on these patients so far
Cheung et al. Arch Surg. 144:1127–1132
Pirlet et al. Surg Endosc. 25(6):1814–1821
Van Hooft et al Lancet Oncol Apr;12(4):344-52

15. Mortality and morbidity
One trial terminated for increased 30-day morbidity in colonic stenting group
No significant difference in mortality and morbidity in subsequent analysis
In contrast, another trial terminated for high anatomsotic leakage rates in emergency arm
Mortality rate 6.9% in SEMS group Vs 5.9% in emergency surgery
No significant difference in in-hospital mortality
In contrast to previous comparative ies and metaanalysis which showed a decrease mortality in elective surgery group studDecrease in mortality, decrease medical complications Tilney et al. Surg Endosc. 2007; 21:
Tan et al Br J Surg. 2012; 99: 469–476

16. Anastomotic leakage
Significantly lower rate in stenting group in the single centered RCTs
0% in stent group Vs % in emergency group
No significant difference in meta-analysis
Decrease leakage 11 % Vs 3% saida
Zhang et al. Surg Endosc ;26:110–119
Tan et al Br J Surg 2012; 99: 469–476

17. Validity of this meta analysis?
Small sample size in each RCT
Contradicting results between studies
Endoscopist / radiologist experience
Multi-center participation
Variability in outcomes, experience of endoscopist, single and multicentered

18. Oncological safety No difference in 3 and 5 year survival
Elevated level of CK20 mRNA with endoscopic colonic stenting
14% of silent perforations in histological examination of resected specimens in stented group
Safety has yet to be further explored with survival studies
Questioned by many studies
Saida: Long term prognosis: 3 and 5 yr OS didn’t differ ( 50 Vs 48%), 44Vs 40%
CK20 epithelial cells in GI tract, but is no expression seen in controls. Indication tumour cell dissemination in peripheral circulation
Law, Carne : palliative
Jin: pairing obstructive Vs non obstructive , so obstructive patients should be poorer
colonic obstruction secondary to tumour is known to adversely impact outcome regardless of pathological staging
Silent perforations could have oncological significance as it could potentially result in tumour cells seedling and peritoneal dissemination
Saida et al. Dis Colon Rectum 2003; 46:S44–S4
Maruthachalam et al. Br J Surg 2007; 94:1151–1154
Tan et al Br J Surg 2012; 99: 469–476

19. Cost effectiveness
12%-20% reduction in cost in SEMS group due to shorter hospital stay, lower complication rates and operative cost
23% less surgery per patient
Osman: cost analysis (total hospital stay inclusive of reversal of colostomy, cost of radiology suite/OT, running cost, stents ) more cost effective due to shorter hospital stay and expenditure
cos
Targownik : Decision analysis: quantitative method of estimating cost effectiveness of alternative management.
Difference in cost: secondary hospitalization for restoration of bowel continuity
Additional surgeries and ICU care
Decision model of colonic stent placement and emergency surgery for obstructing cancer of left side of colon, decrease operative procedure by 23%, reduce need for stoma from 43 to 73% (83%)
STOMA COST
Osman et al. Colorectal Dis. 2000;2:233–7
Binkert et al. Radiology 1998;206:199–204
Targownik et al. Gastrointest Endosc. 2004;60:865–74

20. Conclusion
Colonic stents can be considered as a bridge to surgery in patient with acute colonic obstruction
Stenting should be performed by high volume centers with careful patient selection
Further survival analysis is needed to evaluate the impact of silent perforations on patient survival
Patients: probably those with high predicted preoperative mobidity and mortality , further studies are need to definite subgroups who benefits precisely.

21. Reference
Martinez-Santos C, Lobato RF, Fradejas JM, Pinto I, Ortega-Deballon P, Moreno-Azcoita M (2002) Self- expandable stent before elective surgery vs. emergency surgery for the treatment of malignant colorectal obstructions: comparison of primary anastomosis and morbidity rates. Dis Colon Rectum 45:401–406
Tilney HS, Lovegrove RE, Purkayastha S, Sains PS, Weston-Petrides GK, Darzi AW, Tekkis PP, Heriot AG (2007) Comparison of colonic stenting and open surgery for malignant large bowel obstruction. Surg Endosc 21:225– 233
Khot UP, Lang AW, Murali K, Parker MC (2002) Systematic review of the efficacy and safety of colorectal stents. Br J Surg 89:1096–1102
Watt AM, Faragher IG, Griffin TT, Rieger NA, Maddern GJ (2007) Self-expanding metallic stents for relieving malignant colorectal obstruction: a systematic review. Ann Surg 246:24–30
Cheung HY, Chung CC, Tsang WW, Wong JC, Yau KK, Li MK (2009) Endolaparoscopic approach vs conventional open surgery in the treatment of obstructing left-sided colon cancer: a randomized controlled trial. Arch Surg 144:1127–1132
Pirlet IA, Slim K, Kwiatkowski F, Michot F, Millat BL (2011) Emergency preoperative stenting versus surgery for acute leftsided malignant colonic obstruction: a multicenter randomized controlled trial. Surg Endosc 25(6):1814–1821
van Hooft JE, Bemelman WA, Breumelhof R, Siersema PD, Kruyt PM, van der Linde K, Veenendaal RA, Verhulst ML, Marinelli AW, Gerritsen JJ, van Berkel AM, Timmer R, Grubben MJ, Scholten P, Geraedts AA, Oldenburg B, Sprangers MA, Bossuyt PM, Fockens P (2007) Colonic stenting as bridge to surgery versus emergency surgery for management of acute leftsided malignant colonic obstruction: a multicenter randomized trial (Stent-in 2 study). BMC Surg 7:12
Sebastian S, Johnston S, Geoghegan T, TorreggianiW,Buckley M. Pooled analysis of the efficacy and safety of self- expanding metal stenting in malignant colorectal obstruction. Am J Gastrenterol 2004; 99: 2051–2057.
Tan, C. J., Dasari, B. V. M. and Gardiner, K. (2012), Systematic review and meta-analysis of randomized clinical trials of self-expanding metallic stents as a bridge to surgery versus emergency surgery for malignant left-sided large bowel obstruction. Br J Surg, 99: 469–476. doi:  /bjs.8689
Zhang Y , Shi J , Shi B , et al.  Self-expanding metallic stent as a bridge to surgery versus emergency surgery for obstructive colorectal cancer: a meta-analysis . Surg Endosc ;26:110–119

22. Thank you