Smoking and Thromboangitis Obliterans– Are they related ?

Introduction: In 1908 Leo Buerger first gave the world the clinical picture of this dreadful disease which he called Thromboangitis Obliterans. Virtually all investigators believe that smoking or tobacco use in some form is a requirement for the diagnosis of Thromboangitis Obliterans. We studied the demographic profile and smoking pattern of patients with Thromboangiitis Obliterans. Methods: Retrospective study carried out in a tertiary level hospital of South India from 1st January 1997 to 31st December 2003. Patients fulfilling Shionoya’s criteria form the study group. Incidence of Thromboangitis Obliterans, relation to smoking habits, type and nature of manifestation were analyzed. results: A total of 105 cases were studied and found to have declining pattern of incidence from 0.9%-0.3%. All patients were males, smokers at the time admission and 76% out of them were from low socioeconomic background. Patients smoking 5-15 cigarettes per day, for 5-10 years duration constituted 45% of the study group. The most frequent reasons for being referred to hospital were ischemic ulcers (83.80%), claudication (78.0%) and rest pain (26.66%). conclusions: In those who present early with the disease the number of cigarettes and duration of smoking shows no direct correlation to the severity. Most patients continue to smoke inspite of counseling and awareness that the disease progresses due to smoking. Ulcer, intermittent claudication and rest pain are the three common presenting symptoms of Thromboangitis Obliterans. _______________________________________________________________________________________


INtrODUctION
Thromboangitis obliterans (TAO) is a non-atherosclerotic segmental inflammatory disease that most commonly affects the small and medium sized arteries and veins in the upper and lower extremities. Tobacco is attributed to play a central role in both the initiation and continuation of the disease. TAO most frequently occurs between the ages of 25-40 years. Formerly considered to be exclusively a disease of the male, recent reports show that there is an increase in the incidence of the disease in the female, consistent with the increase in their smoking habits. The reported incidence of Buerger's disease in women was 1% to 2 % in most published series of cases before 1970. TAO is known to occur the world over, and no race or color is known to be immune to this disease. 1 Most studies have reported a preponderance of patients in the low socioeconomic strata of society, particularly farmers. 2 However no particular occupation is implicated. Also, geographic location and climatic condition are questionable factors.
Although TAO occurs most commonly in the infrapopliteal and brachial arteries, it is not uncommon to see involvement of the superficial femoral artery. No region of the extremity (both upper and lower) is exempt. There are widely varying prevalence rates of Buerger's disease in patients with peripheral arterial disease in Europe and Asia. For example, the rates of TAO among all patients with peripheral arterial disease have been reported in 0.5% to 5.6% in Western countries. 3% in Poland, 6.7% in East Germany, 11.5% in Czechoslovakia, 39% in Yugoslavia, 80% in Israel, 45% in India and 16% to 66% in Korea and Japan. 3,4 Several different diagnostic criteria have been proposed for the diagnosis of TAO. Papa and Adar 5 have put forth various clinical, angiographic, histopathologic, and exclusionary criteria, and in a second report, they suggested a point scoring system to help make the diagnosis of Buerger's disease. Mills and Porter 6 have proposed major and minor diagnostic criteria for the diagnosis of Buerger's disease. Wong's 7 Last RJ 8 and S. Shinoya 9 proposed different clinical criteria to diagnose TAO respectively. Apart from clinical criteria several pathological and imaging criteria have been suggested by various authors.
We have attempted to study the relationship between the incidence of TAO and smoking habits in the population studied.

MEtHODs
In this retrospective clinical study, we studied patients admitted to the various surgical units of Kasturba Hospital, Manipal India. The period of study is 7 years from 1 st January 1997 to 31 st December 2003. The total number of patients in this study is 105. Admission per year ranged from 8 to 23 with a mean of 16 patients per year. Among the patients with peripheral arterial occlusive disease, only those satisfying Shinoya's criteria were included in this study. We analyzed the incidence, relation to smoking habits, type and nature of manifestation as compared with the data available in the literature. It was with this background that we embarked on this retrospective clinical study to obtain data for analysis and comparison with the literature.

rEsULts
In our study all 105 patients were male (100%). Four patients were business men, 12 were in services and the remaining 84 patients were from the low socio economic groups, including manual laborers, farmers, fishermen and beedi workers. There was no record of the occupation for five patients. In this study its yearly incidence, age, number of cigarette smokers, duration of smoking, and presentation with rest pain, intermittent claudication and ulcer are as shown in Table 1-5. In our retrospective study we had used 50 years as the upper age limit in the inclusion criteria. Patients were divided into three groups: 21-30 years, 31-40 years and 41-50 years.  In our series the disease appeared early in 49 patients (45%) who smoked (5-15 cigarettes) per day, for minimum duration of (5-10 years) of smoking. In our study, the number of cigarettes and the duration of smoking show no correlation in the early presentation of Buerger's disease. This contradicts with other studies. The reason may be that smoking may or may not be the sole primary etiological factor otherwise all heavy smokers in the world would have been exposed to the risk of TAO. Tobacco use may be central to initiation and progression of the disease. There possibly are other factors, which play some role as triggering mechanism for development of TAO in susceptible individuals. So the number of cigarettes or the duration of smoking may not be criteria that are helpful to diagnose TAO. One should temper this observation from a retrospective study with the possibility of under-reporting of smoking habits, in particular the number of cigarettes smoked. It is a common observation amongst our surgical patients who report they have quit smoking that it was since the hospital admission.
Counseling the patient aggressively on the importance of discontinuing the use of all tobacco products as well as to avoid passive smoking is the cornerstone of therapy. Although in our study 17.2% of the patients quit smoking after counseling, no markers like urine nicotine and cotinine estimation were used to biochemically verify the truth. Among 164 admissions in the 105 patients of the study group, 12 (11.42%) patients in second admission and 12 (11.42%) patients in the third or more admissions, quit smoking, but still 20 (19.04%) patients in second admission and 15 (14.28%) patients in third or more admissions, were still smoking. It seems vigorous counseling at the time of diagnosis and first admission did motivate a number of patients to quit smoking, which is the first measure to be adopted for treatment.

cONcLUsIONs
Ulcer, intermittent claudication and rest pain are the three common presenting symptoms of TAO. The incidence of TAO is declining, commonly affecting male smokers between 31 and 50 years. Smoking habits have wide variation varying with the region where studies are conducted.TAO occurs more frequently in the low socioeconomic groups. In those with an early presentation of TAO the number of cigarettes and duration of smoking show no direct correlation to the disease. Most patients continue to smoke inspite of counseling and awareness of disease progression due to continued smoking.