Original Article Does case selection and outcome following laparoscopic colorectal resection change after initial learning curve? Analysis of 235 consecutive elective laparoscopic colorectal resections Kurumboor Prakash, N P Kamalesh, K Pramil, I S Vipin, A Sylesh, Manoj Jacob Department of GI Surgery, PVS Memorial Hospital, Kochi, Kerala, India Address for Correspondence: Dr. K. Prakash, Department of GI Surgery, PVS Memorial Hospital, Kochi, Kerala, India. E-mail: drkprakash@vsnl.com Abstract INTRODUCTION: Laparoscopic colorectal surgery is being widely practiced with an excellent short-term and equal long-term results for colorectal diseases including cancer. However, it is widely believed that as the experience of the surgeon/unit improves the results get better. This study aims to assess the pattern of case selection and short-term results of laparoscopic colorectal surgery in a high volume centre in two different time frames. MATERIALS AND METHODS: This study was done from the prospective data of 265 elective laparoscopic colorectal resections performed in a single unit from December 2005 to April 2011. The group was subdivided into initial 132 patients (Group 1) from December 2005 to December 2008 and next 133 patients () between December 2008 and April 2011 who underwent laparoscopic colorectal resections for cancer. The groups were compared for intraoperative and perioperative parameters, type of surgery, and the stage of the disease. RESULTS: The age of patients was similar in Groups 1 and 2 (57.7 and 56.9, respectively). Patients with co-morbid illness were significantly more in than in Group 1 (63.2% vs. 32.5%, respectively, P 0.001). There were significantly more cases of right colonic cancers in Group 1 than in (21.9% vs. 11.3%, respectively, P<0.02) and less number of low rectal lesions (20.4% vs. 33.8%, respectively, P 0.02). The conversion rates were 3.7% and 2.2% in Groups 1 and 2, respectively. The operating time and blood loss were significantly more in Group 1 than in. The ICU stay was significantly different in Groups 1 and 2 (31.2± 19.1 vs. 24.7± 18.7 h, P 0.005). The time for removal of the nasogastric tube was significantly earlier (P=0.005) in compared to Group 1 (1.37± 1.1 vs. 2.63±1.01 days). The time to pass first flatus, resumption of oral liquids, semisolid diet, and complications were similar in both groups. The hospital stay was more in Group 1 than in (P 0.01). The numbers of lymph nodes retrieved was similar in both groups. The T stage of the disease in Groups 1 and 2 were similar, however, the number of T4 lesions was significantly more in (8.3% vs. 18.7%, respectively, P<0.01). CONCLUSION: This study shows that with increasing experience, laparoscopic colorectal surgery can be practiced safely with minimal conversion rates and morbidity. As the units experience improves, there is a trend towards selecting advanced cases and performing complex laparoscopic colorectal procedures. With increasing experience, there is a trend towards better short-term outcome after laparoscopic colorectal surgeries. Key words: Case selection, laparoscopic colectomy, learning curve, short-term results INTRODUCTION Quick Response Code: Access this article online Website: www.journalofmas.com DOI: 10.4103/0972-9941.115366 The first successful laparoscopic sigmoidectomy for cancer was reported in 1991 by Jacob s et al. [1] Although the potential benefits of laparoscopy in colorectal surgery have been noted in the early experience [2,3] the procedure was not accepted worldwide like laparoscopic cholecystectomy. This was due to concerns regarding port site recurrences in laparoscopic approach [4] lack of data on long-term oncological Journal of Minimal Access Surgery July-September 2013 Volume 9 Issue 3 99
outcome and also as the procedure is technically demanding. These concerns have been addressed by several prospective randomized clinical trials on laparoscopic colorectal surgery versus open surgery with the large sample size and longer follow-up. [5-9] These trials have reported local recurrence and long-term survival results of the laparoscopic approach comparable with open colorectal resections. Laparoscopic colorectal resection is technically complex as it involves laparoscopic mobilization of colon through various tissue planes, dissection and division of major vessels, and division of bowel and anastomosis. This requires specialized equipment, energy sources, laparoscopic staplers and it has been noted that this procedure has a definite learning curve. [10-12] Our unit began practicing laparoscopic colorectal surgery from 2005 onward. We have published our early experience of laparoscopic surgery for left colonic resections in comparison with open resections and demonstrated the feasibility and better short-term outcomes. [13] However, we feel that following the initial learning experience, as the experience of the unit improves over time, there is a trend towards inclusion of difficult and complex resections and inclusion of patients with more advanced stage of disease. This paper analyses the pattern of case selection and its outcome following laparoscopic colorectal resection after the initial learning experience of a unit. MATERIALS AND METHODS Our centre is a tertiary referral unit for colorectal surgery for the last 15 years. This unit started laparoscopic colorectal surgery in December 2005. The clinical parameters, operative parameters, and short- and long-term outcome details following laparoscopic colorectal surgery were collected from a prospective database. Between December 2005 and April 2011, there were 265 patients who had various laparoscopic colorectal resections. This group was equally subdivided into initial 132 patients (Group 1) and next 133 patients () who underwent laparoscopic colorectal resections. Selection of Patients and Inclusion Criteria All the procedures were performed by trained consultant surgeons assisted by residents. These surgeons had sufficient experience in open colorectal surgery and had undergone training in laparoscopic colorectal surgery. All patients, apart from routine evaluation, underwent colonoscopic biopsy and contrast-enhanced multi-slice CT scan to stage the lesion preoperatively. In patients with small/early lesions, preoperative colonoscopic tattooing with India ink dye was performed to facilitate localization of tumors during laparoscopy. Patients with previous colonic resection, comorbidity precluding GA, coagulopathy and metastatic disease were excluded. Patients with features of colonic obstruction and suspected perforation were relative criteria for exclusion and they were offered laparoscopic resection selectively, depending on the comorbid status and local staging. All other patients were offered the laparoscopic approach during the study period. Surgical Procedure and Outcome Measures The details of the preoperative preparation and the technique of the surgery have been reported earlier. [13] Briefly, we follow medial to lateral dissection and ligation of vessels first. Following mobilization, the specimen is removed through a small incision with adequate protection of the wound and bowel continuity is restored by stapled anastomosis or handsewn anastomosis as per the clinical situation. The decision to make a diversion stoma was left to the discretion of the surgeon. For the purpose of this study, right colectomy is defined as resections involving caecum, ascending colon and transverse colon up to splenic flexure and left colectomy indicates resections from splenic flexure to the anal canal. Demographic features of the patients, preoperative variables such as location of tumor, stage, etc. were noted in detail. The intraoperative parameters analyzed include operating time, blood loss, blood transfusion, conversion to open surgery and use of temporary colostomy. The number of lymph nodes retrieved, the distal margin, radial margin and pathological staging were also compared. Postoperative outcome measures considered were duration of stay in the intensive care unit (ICU), passage of flatus/stools and resumption of oral liquids. Postoperative complications in both groups and hospital stay were also compared. The statistical analysis was performed using c 2 -test and Student s t-test using SPSS Statistics 17.0 version software. RESULTS Patient Demography, Site of the Lesion and Types of Surgeries There were 132 patients in Group 1 and 133 patients in with a mean age of 57.7 years and 56.9 years, respectively (P=ns). The male-to-female ratio was also similar in both groups. The patient demographics and the details about the site of the lesion in both groups are given in Table 1. The number of patients with co-morbid illnesses was significantly more in than in Group 1 (63.2% vs. 32.5%, respectively, P 0.001). There was more number of patients with obstruction or localized perforation in though this was not statistically significant. Similarly, the percentage of patients who had undergone previous 100 Journal of Minimal Access Surgery July-September 2013 Volume 9 Issue 3
Table 1: Patient demographics and site of lesion Age 57.7 56.93 Ns Male: Female ratio 75:57 80:53 Ns Systemic illness 43 (32.5%) 84 (63.2%) <0.001 Obstruction/perforation 3 (2.27%) 7 (5.2%) Ns Previous abdominal surgery 15 (11.36%) 23(17.2%) Ns Site of the lesion: Low rectum 27 (20.4%) 45 (33.8%) <0.02 Mid / upper rectum 32 (24.2%) 33 (24.8%) Ns Rectosigmoid/left colon 39 (29.5%) 31 (23.3%) Ns Transverse colon 1 (0.7%) 1 (0.75%) Ns Right colon 29 (21.9%) 15 (11.3%) <0.02 Pan colonic involvement 4 (3.03%) 8 (6.02%) Ns Type of surgeries Right colon resection 29 (21.9%) 15 (11.3%) <0.05 Left colectomy 99 (75%) 110 (82.7%) Ns Proctocolectomy 4 (3.03%) 8 (6.02%) Ns Right hemicolectomy 26 (19.7%) 11 (8.27%) <0.01 Extended right colectomy 3 (2.3%) 4 (3.1%) Ns Low anterior resection 34 (25.7 %) 61 (45.8%) <0.001 High anterior resection 26 (19.7%) 22 (16.5%) Ns Sigmoid/Left colectomy 30 (22.7%) 22 (16.5%) Ns Abdominoperineal resection 9 (6.8%) 5 (4.5%) Ns Table 2: Intra, peri, and postoperative outcomes Intraoperative parameters Operation time (min) 278±76.3 231±68.8 <0.005 Blood loss (ml) 164.42±174 99.3±80.2 <0.001 Blood transfusion (no) 6 (4.54%) 3 (2.25%) Ns Conversion 5 (3.7%) 3 (2.25%) Ns Stoma 17 (12.8%) 18 (13.5%) Ns Perioperative Parameters ICU stay 31.18±19.1 24.7± 18.3 <0.005 NG tube removal 2.63±1.01 1.377±1.07 <0.005 Flatus 3.99±0.99 3.79±1.2 Ns Oral liquids 4.56±1.08 4.25±1.45 Ns Semisolid diet 7.73±1.8 7.41±2.2 Ns Hospital stay 9.3±2.37 8.6±2.4 <0.01 Postoperative complications Surgical site infection 10 (7.5%) 9 (6.7%) Ns Anastomotic leak 4 (3.03%) 5 (3.75%) Ns Intra-abdominal abscess 2 (1.51%) 2 (1.5%) Ns Intestinal obstruction 7 (5.3%) 6 (4.5%) Ns Re-exploration 2 (1.51%) 3 (2.25%) Ns Pulmonary complication 2 (1.51%) 2 (1.5%) Ns Cardiac events 3 (2.27%) 3 (2.25%) Ns Deep vein thrombosis 2(1.51%) 2 (1.5%) Ns Morbidity 13 (9.8%) 11 (8.2%) Ns abdominal surgery was 11.36% in Group 1 compared to 17.2% in (P=ns). These surgeries were for open hysterectomies through 27 patients, midline laparotomy for various indications in 9 patients and 2 patients had paramedian incision for appendicectomy. The number of right colon lesions were significantly different (21.9% vs. 11.3% in Groups 1 and 2, respectively, P<0.02), but the number of left colectomies were not significantly different [Table 1]. However, the number of low rectal lesions (20.4% vs. 33.8%, P 0.02) and low anterior resections were significantly more in (25.7 % vs. 45.8%, P<0.001). The distribution of lesions in the rest of the colon was similar between both groups. The number of high anterior resections, sigmoid colectomies, left colectomies, abdomino-perineal resections and proctocolectomies were similar between the groups. Short-Term Outcomes Mean operating time was significantly longer in Group 1 than in (278 vs. 231 minutes, P<0.005) and the mean blood loss was significantly more in the Group 1 than in (164.4 vs. 99.3 ml, P<0.001). The number of blood transfusion, the rate of conversion, the number of protective stomas created, etc. were similar in both groups [Table 2]. The reasons for conversion in Group 1 were inadequate distal resection margins in two cases, difficulty in mobilization in two cases and bleeding in another case. In, one patient was converted for bleeding and another two were converted for a bulky low rectal tumor wherein it was difficult to negotiate endoscopic stapler satisfactorily. In the comparison of immediate postoperative parameters, the ICU stay was significantly shorter in (P<0.005) and the removal of nasogastric tube was significantly earlier in compared to Group 1 (P<0.005). However, the time to pass first flatus after surgery, resumption of oral liquids and semisolid diet were similar between Groups 1 and 2 [Table 2]. The hospital stay was more in Group 1 than in (9.3 vs. 8.6 days, P<0.01). The incidence of complications and morbidity were also similar between the groups [Table 2]. Four patients with postoperative intestinal obstruction required re-exploration, three for port site herniation and one for adhesive obstruction. Morbidity for the purpose of this study included anastomotic leaks, reexplorations, and surgical site infections, pulmonary, cardiac or other complications prolonging hospital stay due to these complications. Two patients in died, one because of cardiac failure and another due to sepsis following gangrene of descending colon on second postoperative day and there was no mortality in Group 1. The number of lymph nodes retrieved (18.1 vs. 17.4) and the status of margin involvement were similar in both groups [Table 3]. When the histological features were compared, the incidence of Tl-3 lesions were similar in Groups 1 and 2; however, the number of T4 lesions were significantly more in Group 1 than in (8.3% vs.18.7%, respectively, P<0.01). The status of margin involvement in histology was similar; with three patients in Group 1 and two patients in Journal of Minimal Access Surgery July-September 2013 Volume 9 Issue 3 101
Table 3: Histopathology features and staging having microscopic distal margin involvement. Radial margin involvement was seen in two patients in Group 1 and four patients in (P=ns). When the lesions were stratified according to the TNM stage, the number of patients with Stages I, II and III were similar in both groups and the patients. There were two patients in Group1 and nine patients in with synchronous liver metastases (P=ns). One patient in Group 1 and five patients in underwent simultaneous laparoscopic non-anatomical resection of liver metastasis as well. DISCUSSION Number of nodes 18.1±6.7 17.4±4.2 Ns Distal margin involvement 3 (2.27%) 2 (1.5%) Ns Radial margin involvement 3 (2.27%) 4 (3.1%) ns T1 16 (12.1%) 12 (9.02%) Ns T2 29 (21.9%) 22 (16.5%) Ns T3 76 (57.5%) 74 (55.6%) Ns T4 11 (8.3%) 25 (18.7%) <0.01 TNM Stage I 21 (15.9%) 17 (12.7%) Ns TNM Stage II 45 (34.1%) 35 (26.3%) Ns TNM Stage III 62 (46.9%) 73 (54.8%) Ns TNM Stage IV 4 (3.03%) 8 (6.01%) Ns Laparoscopic colorectal resection has gained popularity in India; but even then it is being practiced exclusively in selected centres in selected patients. Selection of patients for laparoscopic surgery is generally practiced worldwide according the institutional policies. Most of the randomized trials have excluded transverse colon tumours as they are rare and technically difficult. [5-9] The procedure is technically demanding and is associated with a definite learning curve. [10-12] A German multicentre study to assess the quality of oncologic resections has demonstrated a marked variability in the number of lymph nodes harvested among surgeons and has also shown increase in number of nodes over time, indicating improvement in the oncologic resection with increasing case volume. [14] Most randomized trials quote that the experience of a minimum of 20 cases is required by the participating surgeons to overcome this learning curve. [6,9] MRC CLASSIC trial has shown improvement in conversion rates from 34% in first year to 16% in 6th year with increasing experience [9] It is generally believed that with improving experience there is improvement in conversion rate and short-term outcome of patients. Selection criteria for laparoscopic colorectal resections vary widely with some series exclude those patients with obesity, multiple abdominal surgeries, multiple primary tumors, locally advanced or metastatic disease and those with features of intestinal obstruction. [8,10] This is mainly because of the technical difficulties in mobilization of colon, difficulties in dissection and control of vascular pedicle in these patients. Consequently, there is more chance for conversion to open surgery and chance for poor outcome. [10,11,15,16] Tekkis et al. [11] has demonstrated that the conversion rates vary with experience, with conversion rates varying from 20.7% conversion rate in initial 25 cases to 10.7% after 100 cases and 5.5% after 175 cases. Similarly, as the surgeon or the unit gain proficiency in laparoscopic colorectal surgery, it has been observed that more difficult resections were taken up without compromising results [9,11] Hence, with increasing experience there is a trend towards including more difficult patients who are normally not taken up for laparoscopic colorectal surgeries. A similar trend is noticed in the current study as the study population includes few patients with obstruction, perforation and those with previous abdominal surgeries. A significantly more number of low anterior resections were also performed in the latter half of study (25.7% vs. 45.8%). Despite this, our conversion rate is low with a trend towards improvement with 3.7% in Group 1 and 2.25% in patients. The complications and morbidity rates were also not different between the groups. This has been observed in other studies as well, that with better experience surgeons tend to be more liberal in case selection without major changes in the outcome. [16,17] Another trend noticed in this study is a significant increase in number patients with systemic illness, more low anterior resections and though not statistically significant, more difficult procedures like extended resections and proctocolectomies. Similarly, there was significant difference in the number of bulky or locally advanced cases with 8.3% and 18.3% cases in Groups 1 and 2, respectively. These facts indicate that as the unit s experience improves there is a trend towards accepting more advanced diseases and technically complex operations with good results. Similar observations have been reported in the literature. [11,16] Marusch et al. [16] in a multicentre study of 1658 patients have demonstrated that surgeons with more than 100 laparoscopic colorectal resections are likely to embark upon more technically demanding operations with a conversion rate of 4.3% compared to 6.9% in those with less than 100 cases experience without any increase in complications and mortality. Similarly Shah et al. [12,17] has observed that with increasing experience, in a progressive time phase there is an increasing work load score and case mix without increase in complications or conversion. The same observations are made in the current study as well. This indicates that after the initial learning curve of 20-30 patients, with better experience 102 Journal of Minimal Access Surgery July-September 2013 Volume 9 Issue 3
and volume difficult laparoscopic colectomy can be safely performed with a minimal rate of conversion. In the current study, when the data of all consecutive patients was analyzed in two time frame groups a significant improvement in the operating time, blood loss, shorter ICU stay, early removal of nasogastric tube and less hospital stay was noted in the later part of the time frame. However, there was no significant difference between bowel movement and resumption of oral diet. Similarly, the conversion rate, complications and lymph node harvested were not different in the two groups. We feel that after the initial learning curve, as the unit s experience cross 90-100 cases there is a trend towards improvement in case selection, conversion rates and in performing more difficult operations with comparable postoperative results and short-term outcome. CONCLUSION This study shows that with increasing experience laparoscopic colorectal surgery can be practiced safely with minimal conversion rates and morbidity. As the unit s experience improves, there is a trend towards selecting difficult cases and performing complex laparoscopic colorectal resections. Although there was less blood loss, less ICU stay, early removal of nasogastric tube and short hospital stay with improving experience, the overall short-term outcomes are comparable even when advanced and complex procedures are taken up by an experienced team. Hence, following the initial learning curve, more complex laparoscopic colorectal procedures can be safely taken up without compromising short-term outcome. REFERENCES 4. Berends FJ, Kazemier G, Bonjer HJ, Lange JF. Subcutaneous metastases after laparoscopic colectomy. Lancet 1994;344:58. 5. Lacy AM, Gorcr a-valdecasas JC, Delgado S, Castells A, Touro P, Pique JM, et al. Laparoscopy-assisted colectomy versus open colectomy for treatment of non-metastatic colon cancer; a randomized trial. Lancet 2002;359:2224-9. 6. The Clinical Outcomes of Surgical Therapy (COST) Study Group. A comparison of laparoscopically assisted and open colectomy for colon cancer. N Engl J Med 2004;350:2050-9. 7. Fleshman J, Sargent DJ, Green E, Anvari M, Stryker SJ, Beart RW Jr, et al. The Clinical Outcomes of Surgical Therapy Study Group. Laparoscopic colectomy for cancer is not inferior to open surgery based on 5-year data from the COST Study Group trial. Ann Surg 2007;246:655-62;discussion 662-4. 8. Buunen M, Veldkamp R, Hop WC, Kuhry E, Jeekel J, Haglind E, et al. Colon Cancer Laparoscopic or Open Resection Study Group, Survival after laparoscopic surgery versus open surgery for colon cancer: Long-term outcome of a randomised clinical trial. Lancet Oncol 2009;10:44-52. 9. Jayne DG, Guillou P J, Thorpe H, Quirke P, Copeland J, Smith AM, et al. UK MRC CLASICC Trial Group. 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Prospective multicenter study of the quality of oncologic resections in patients undergoing laparoscopic colorectal surgery for cancer. The Laparoscopic Colorectal Surgery Study Group. Dis Colon Rectum 1998;41:963-70. 15. Belizon A, Sardinha CT, Sher ME. Converted laparoscopic colectomy: What are the consequences? Surg Endosc 2006;20:947-51. 16. Marusch F, Gastinger I, Schneider C, Scheidbach H, Konradt J, Bruch HP, et al. Importance of conversion for results obtained with laparoscopic colorectal surgery. Dis Colon Rectum 2001;44:207-14. 17. Shah PR, Gupta V, Haray PN. A unique approach to quantifying the changing workload and case mix in laparoscopic colorectal surgery. Colorectal Dis 2011;13:267-71. 1. Jacobs M, Verdeja JC, Goldstein HS. Minimally invasive colon resection (Iaparoscopic colectomy). Surg Laparosc Endosc 1991:1:144-50. 2. Schwenk W, Bohm B, Muller JM. Postoperative pain and fatigue after laparoscopic or conventional colorectal resections. A prospective randomized trial. Surg Endosc 1998;12:1131-6. 3. Milsom JW, Böhm B, Hammerhofer KA, Fazio V, Steiger E, Elson P. A prospective, randomized trial comparing laparoscopic versus conventional techniques in colorectal cancer surgery: A preliminary report. J Am Coil Surg1998:187:46-54;discussion 54-5. Cite this article as: Prakash K, Kamalesh NP, Pramil K, Vipin IS, Sylesh A, Jacob M. Does case selection and outcome following laparoscopic colorectal resection change after initial learning curve? Analysis of 235 consecutive elective laparoscopic colorectal resections. J Min Access Surg 2013;9:99-103. Date of submission: 07/02/2012, Date of acceptance: 08/08/2012 Source of Support: Nil, Conflict of Interest: None declared. Journal of Minimal Access Surgery July-September 2013 Volume 9 Issue 3 103