6. BRIEF RESUME OF THE INTENDED WORK
6.1 NEED FOR THE STUDY:
Liver abscess is a common condition in India. It is associated with high morbidity and mortality. It is a common disease of the tropical region. Abscess develops in liver due to various reasons, but is broadly classified into Amoebic and pyogenic. Colonic Amoebae are mainly responsible for the development of the abscess. The options in managing Amoebic liver abscess are medical and percutaneous or open surgical drainage. Uncomplicated Amoebic liver abscess has been managed conservatively with amoebicidal and antibiotic drugs. However, ultrasound guided pigtail catheter drainage has been advocated more recently. There are different views and protocols for the management of this disease.
The review of literature reveals that the smaller Amoebic liver abscesses, (multiple or single) can be treated conservatively. Larger Amoebic liver abscesses or Amoebic liver abscess with complications (prerupture, rupture, pressure effects) require intervention in the form of either closed or open drainage. However, there is no clear cut consensus for the management of uncomplicated symptomatic medium sized Amoebic liver abscesses with treatment modalities ranging from drugs alone to needle aspiration to pigtail catheter drainage. The present study is an effort to establish an objective criterion for management of such abscesses. Our study is designed to find out which mode is helpful and ideal for a particular patient with reference to severity of disease and safety of the patient. Effective management of the disease would help in decreasing morbidity and mortality associated with the disease.
6.2 REVIEW OF LITERATURE:
The management of Amoebic liver abscess varies from conservative management, needle aspiration and pigtail catheter drainage to open drainage depending on various criteria. Amoebic liver abscess untreated has a very high mortality rate of up to 70 to 80 %, but with early institution of specific therapy prognosis is excellent. The treatment and diagnosis of the disease has changed dramatically due to the availability of newer amoebicidal drugs, percutaneous techniques, surgical and post op care.
Before 1900, the treatment of Amoebic liver abscess was primarily of incision and drainage (open method), but the procedure was associated with high mortality of up to 60% 1.
According to Akgun Y, Tacylidiz et al medical management is indicated in cases with abscess size of 5cm or less 2 whereas Joerg Blessmann et al 3 comparing conservative management with needle aspiration concluded that improvement in liver tenderness was significantly faster in aspiration group .Drug treatment alone is sufficient in uncomplicated cases with a diameter up to 10 cm in the right lobe.
Hanna et al 4 in his study concluded that catheter drainage should be a routine use in drug resistant cases because it is safe and highly successful.
Mcgarr et al 5 in their study evaluating the efficacy of conservative management policy concluded that medical management is safe and drainage procedures are indicated only in patients who don’t improve clinically after 48-72 hours rather than a rigid criterion.
AIMS AND OBJECTIVES
1. To study the therapeutic efficacy of conservative management and ultrasound guided pigtail drainage of Amoebic liver abscess.
2. To compare the two modalities of treatment of amoebic liver abscess.
3. To study the safety and outcome of ultrasound guided drainage of abscess.
7. MATERIALS AND METHODS
The study is to be conducted in The Department of General Surgery, M.S. Ramaiah Medical College & Teaching Hospital from May 2010 till Oct 2012 on patients who will be admitted from casualty and outpatient department with a diagnosis of amoebic liver abscess (ALA). The diagnosis of ALA is based on history of anorexia, malaise, fever and pain abdomen with or without a preceding history of diarrhea and findings of tender hepatomegaly, leucocytosis amoebic serology and ultrasound evidence of amoebic liver abscess. Patients will be randomly allocated into two groups,
7.1 CASE GROUP
STUDY GROUP which will be further subdivided as:
Study Group I: These patients to be treated with antiamoebic (metronidazole) and antibiotic (ciprofloxacin) drugs - 20 in number
Study Group II: These patients to be treated by ultrasound guided indwelling pigtail catheter drainage in addition to antiamoebic (metronidazole) and antibiotic (ciprofloxacin) drugs - 20 in number.
Inclusion criteria:
Patients with amoebic liver abscess with size of abscess of not more than 10cm.
Exclusion Criteria:
a. Impending rupture d. Toxic patients (secondary infection)
b. Ruptured abscess e. Ascites
c. Jaundice
7.2Methodology
The patients in the study group were subjected to:
1. A complete general medical and physical examination
2. Specific Investigations
i) Complete Haemogram.
ii) Liver function test.
iii) Amoebic serology test.
iv) Prothrombin time.
v) Ultrasound Abdomen.
vi) Chest X-ray.
vii) Microscopic examination and culture of aspirated pus (Group II).
viii) Air cavitogram will be done in Group II patients.
The patients will be examined daily for clinical improvement. Improvement in pain, fever anorexia and hepatomegaly within 72 hours of institution of therapy will be considered as criteria for continuing that particular modality of treatment.
Amoebic Serology:
Method: Enzyme linked immunosorbant assay (ELISA) for serum IgG antibodies against Entamoeba histolytica will be used. Serological tests will be useful in detecting infection by E. histolytica if organism goes extra-intestinal.
Quality Control:
Negative control should be < 0.3 OD units.
Positive control should be > 0.5 OD units.
Interpretation
Tests sample > 0.4 OD units will be considered positive.
Air Cavitogram
Air cavitogram will be done in Group II patients at the time of removal of pigtail catheter when the drainage has decreased and the ultrasound findings suggest that the abscess contents are minimal. It will be done by injecting air (volume approx. 20-30ml) into the cavity through the pigtail. X-rays will be taken before and after injecting air. Position of the pigtail, fluid level inside the abscess cavity and size of the abscess cavity will be checked.
TECHNIQUE OF PIGTAIL CATHETER INSERTION
The standard pigtail external drainage catheter used in the present study is an angiographic-type polyethylene tube, usually ranging in size from No 16 to 18 Fr, with the distal end tapered Catheter is accompanied with trocar and cannula.
Procedure:
The position of the patient is determined by transabdominal sonography using 3.5-5 MHz transducer. At the start of the procedure, Intravenous cannulation, with intravenous fluid infusion is started. The selected area after being subjected to meticulous surgical toilet is infiltrated with 2 to 3 ml of 1% xylocaine using a twenty four-gauge needle. Adequate time of about 5 min is to be allowed for the anesthetic to act. Before catheter insertion needle aspiration is to be done. A small puncture with a stab knife is made in the skin at the site of pigtail insertion. While the catheter is being introduced or withdrawn, the patient is asked to take shallow breaths throughout the procedure and hold the breath to minimize liver trauma. Drainage will do under ultrasound guidance using 16F – 18 F pigtail catheter with trocar. The pigtail is to be fixed to skin immediately after the procedure. The proper insertion will confirmed at the end of the procedure by ultrasound. The aspirated pus will be sent for culture sensitivity and gram staining to rule out secondary bacterial infection of the amoebic liver abscess. Chest X-ray will be done after catheter drainage to rule out pleural effusion or pneumothorax. Catheter will be flushed daily with 50ml of metronidazole. Catheter output charting will be done daily and chart will be maintained.
Outcome to be assessed by
1. Abdominal pain as quantified.
2. Fever.
3. Liver tenderness.
4. Resolution of amoebic liver abscess ultrasonographically.
5. Resolution of amoebic liver abscess by air cavitogram.
6. Length of hospital stay.
7. Any complication.
At three to five days, patients’ outcome will again be assessed and if they have not responded to the first modality of treatment, the patient will be subjected to second modality of treatment, i.e. conservative converted to pigtail insertion and patients with pigtail insertion converted to open drainage.
7.3 DOES THIS STUDY REQUIRE ANY INVESTIGATIONS OR INTERVENTIONS TO BE CONDUCTED ON PATIENTS OR OTHER HUMANS OR ANIMALS? IF SO, DESCRIBE BRIEFLY
Investigations required:
i) Complete Haemogram.
ii) Liver function test.
iii) Amoebic serology test.
iv) Prothrombin time.
v) Ultrasound Abdomen.
vi) Chest X-ray.
vii) Microscopic examination and culture of aspirated pus (Group II). No animals will be used in the study
The management is based on the basis of current standards of management of liver abscess
Sample size:
Sample size = 40
Sample size estimated using nMaster software (with large proportion equal allocation) on the study reference considering the liver tenderness in conservative method (63%) at 3-5 days and in pigtail group (35%) at 3-5 days.
Hence alpha error was considered on 10% and beta error was 30%
Statistical Analysis
A descriptive statistics of improvement in liver tenderness would be analyzed and expressed in percentage and also descriptive statistics on ESR, CRP, WBC COUNT and HAEMOGLOBIN will be analyzed and expressed in mean and standard deviation.
Chi square test /Fischer test would be employed to compare improvement in various parameters between two groups.
Paired T test / Wilcoxan test would be employed to compare on ESR, CRP, WBC COUNT and HAEMOGLOBIN between two groups.
Design of the study;
Prospective interventional study
7.4HAS ETHICAL CLEARENCE BEEN OBTAINED FROM YOUR INSTITUTION ?
YES, the certificate of the same is enclosed
8. BIBILIOGRAPHY
1. Rogers LM. Amoebic abscess of the liver as an easily preventable disease & post operative sepsis as an important lethal factor. Br Med J 1908; 24:1246-49.
2. Akgun Y, Tacylidiz HI, Celik Y. Amoebic liver abscess: changing trends over 20 years. World J Surg;1999;23: 102-06
3. Blessmann J, Binh Duy H, Hung Manh D, Tannich E, Burchard G . Treatment of amoebic liver abscess with metronidazole alone or in combination with usg guided needle aspiration: a comparative prospective and randomized study. Trop Med Int Health 2003;8:1030 -34
4. Hanna.R.M, Dahniya.M.H, Badr.S.S, . Percutaneous catheter drainage in drug resistant amoebic liver abscess. Trop Med Int Health 2000;5:578-581
5. McGarr.P.L, Madiba. T.E, Thomson.S.R. Amoebic liver abscess - results of a conservative management policy. S Afr Med J 2003;feb:93(2):132-6
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