Follow up pattern for post oesophagectomy patients at a single centre: association with peri-operative variables
S.W.O. Ogendo, MBChB, MMed (Surg), Associate Professor, Department of Surgery, College of Health
Sciences, University of Nairobi, P.O. Box 19676-00202, Nairobi, Kenya
BACKGROUND: Though the operative mortality for resection of oesophageal malignancy has fallen significantly over time, the overall postoperative survival has remained fairly constant irrespective of surgical techniques, preoperative disease spread being the main independent prognostic indicator of survival.
AIM:This is a five year prospective review, from 2001 to 2006, of post oesophagectomy patients, evaluating follow up and associated variables.
MATERIALS AND METHODS: One hundred and seven patients were included into the study. Peri-operative and post discharge data were recorded. Data analysis reviewed the follow up pattern and the relationship to selected variables.
RESULTS: The one, three and five year follow up rates were 30%, 5% and 3% respectively. Although a trend of shorter follow up was noted for the presence of preoperative overweight, (<25Kg/m2), postoperative anastomotic leak and signs of nodal spread of disease, only low preoperative serum protein and albumin levels were significantly associated with a shortened follow up. Seven patients in this series developed recurrent signs of malignant disease.
CONCLUSION: The trends of association of peri-operative variables and postoperative follow up were similar to the international literature on the postoperative survival pattern. Even though this study failed to achieve statistical significance associating disease spread with shortened follow up, improved preoperative staging remains an important goal for better postoperative follow up in this region.
Data on patient survival post oesophagectomy from different centres varies widely (5-year survival rates of 7% to 86% with an average of 21%) (1-4). This wide variation results from the inclusion of both early and late stages of disease in the different reports and differing histology. Illustrating this, King et al. have demonstrated that stage I tumour patients had a survival advantage of up to six times over stage III tumour patients (5).
There have been attempts over the years to reduce operative mortality of oesophageal surgery and to identify factors associated with improved postoperative survival. Though the operative mortality for oesophageal resection has fallen over time, the overall postoperative survival has remained fairly constant irrespective of surgical techniques, the average survival time being about 6 months once metastasis is present (6,7). A review of the situation in a single institution in Japan reports improved 5 year survival from 31% in 1988 to 41% in 1994 as a result of addressing some of these variables relating to improved postoperative survival (8).
Post operative survival and follow up are not necessarily the same thing but may have similar trends. Valid survival data in our region is hampered by poor communication with patients post discharge. This study is a five year prospective review of the follow up of post oesophagectomy patients at the Kenyatta National Hospital, (KNH), Nairobi, and analyses the effect of selected peri-operative variables on the follow up pattern.
Materials and methods
This was a prospective study covering the period from February 2001 to January 2006. All post oesophagectomy patients discharged from the cardiothoracic unit at the KNH were included. The oesophagectomies were performed using the McEven, Ivor Lewis or trans-hiatal resection procedures and the selection of the procedure was at the discretion of the surgeon. For purposes of this study all resections are considered to be palliative therapies and no regional nodal dissection procedures were attempted.
Preoperative parameters evaluated included weight and height to calculate the body mass index (BMI), full haemogram, urea and electrolytes and liver function tests. Additional data included patient demographics, distance of their homes from the Kenyatta National Hospital, the duration of dysphagia and endoscopic and histological information. At surgery, information collected included the visual extent of enlarged paraoesophageal and coeliac nodes. Where significantly enlarged, samples of the nodes were taken with the oesophagectomy specimen for histological examination.
During post discharge clinic follow up, any complications that may have occurred and patient weight on the day of visit were recorded. For postoperative weight change a difference of half a unit or more in the BMI compared to the previous recording was arbitrarily considered to be significant change.
Where a postoperative histological specimen report on the excised oesophagus was present, data on tumour spread through the oesophageal wall and also involvement of the surrounding nodes plus margins was documented. The post resection histology reports of the degree of tumour differentiation, was used for purposes of final analysis, if different to the preoperative endoscopic result.
Data analysis included the determination of the follow up pattern and the variables having an influence on the follow-up pattern. The study endpoint was 31st January 2006. A patient was considered to have reached the end point when the he/she failed to attend clinic follow up for a period of more than three months from the last visit.
Statistical analysis was performed using statistical Package for Social Sciences, (SPSS), version 11.5. Analysis for follow-up data was determined using the Kaplan Mayer method. For the analysis of relationship of follow up and the different variables, the Log Rank test for significance between curves was adopted for categorical data while linear regression model was used for numerical data. Comparison of means was assessed using the student t-test. Significance was considered achieved with a p value of less than 0.05 for the above calculations.
Within the study period the total number of oesophagectomies performed were 129 cases, while those fulfilling the inclusion criteria for the study were 107 patients. The average age for this sample was 57.9 ± 13.9 years with a male: female ratio of 1.8:1.
Final post discharge follow up pattern for all patients is represented in figure 1. Half the patients had dropped out to follow up at seven and a half months. The respective follow up rates for the one, three and five years of follow up were 30%, 5% and three percent.
The occurrence of a postoperative leak (p = 0.0786), a greater number of surrounding enlarged nodes located near the tumour, (p = 0.414), the invasion of tumour through the oesophageal serosal wall, (p = 0.0622) all seemed to have a comparatively shorter follow up compared to patients without leaks or lesser tumour invasion. Despite this apparent picture none of the results were statistically significant; however serosal invasion and post operative anastomotic leak almost attained significance. Also showing an apparent shorter follow up was the resection of tumour using the transhiatal approach over transthoracic, this too however was not statistically significant (p = 0.2505) (Figures 2,3,4,5).
The degree of histological differentiation showed no significant relationship with the follow-up pattern for squamous cell carcinoma (p = 0.1597). Those patients who were overweight preoperatively, (BMI >25kg/m2), displayed a shorter follow up compared to normal, (20kg/ m2 – 25kg/m2), or underweight, (<20kg/m2 ), patients (p = 0.0816), (Figure 7)