Though a German surgeon, Kelling,¹ first demonstrated the use of the peritonescope in 1901, it is only over the last two decades with the great advance in instrumentation and fibre-optics that the endoscopic visualisation of the peritoneal cavity has gained widespread popularity.
Of alI abdominal viscera the Iiver lends itself most readily to peritoneoscopic visualisation. Endoscopic examination of the liver was pioneered by Jacobaeus² (1910), Korbsch³ (1927) and Kalk⁴ (1929) who performed the first endoscopic guided liver biopsy⁵ (1935) opening a new vista of diagnosis in liver disease. Most of the literature on peritoneoscopy and endoscopic diagnosis of liver disease is from the West.⁶ Due to its relatively uncommon occurrence in these parts of the world, scant mention is made of endoscopic visualisation and diagnosis of amoebic liver abscess.
In J.J. Hospital, Bombay, after our nuclear medicine unit started functioning, I became aware that I had difficulty in confirming the diagnosis of amoebic liver abscess on a liver scan in some of the cases of inferior surface abscesses. Udwadia, one of my colleagues, who was doing excel lent work in peritoneoscopy at this hospital, thus got interested in this subject. In the last few years we have demonstrated that in a fair number of cases of amoebic liver abscess, the diagnosis is made easy if both the procedures- liver scan and peritoneoscopy, are available to the patient.^7-9
Over the last six years, out of 780 peritoneoscopies carried out by Udwadia in the surgical unit, 41 cases were referred to him, to exclude the diagnosis of amoebic liver abscess.⁸ In 26 cases, a diagnosis of amoebic abscess could be made by him on peritoneoscopy, in 4 cases the diagnosis was missed and in 11 cases, amoebic liver abscess could be excluded. In a further 6 cases referred as space occupying lesions of the liver a diagnosis of amoebic liver abscess was made endoscopically.
The following were the main indications for which the above 41 patients were referred for peritoneoscopy .

1. Patients suspected of having amoebic live abscess and liver scan showing a cold area on the inferior surface when extrahepatic masses could not be excluded with confidence.
2. A patient of hepatomegaly having a cold area on liver scan and atypical symptoms no fitting into a diagnosis of amoebic liver abscess In absence of serological tests for amoebiasis peritoneoscopy was always relied upon to answer the question of aetiology of the above abnormalities.
3. A negative aspiration in a case diagnoses as amoebic liver abscess.
4. To exclude malignancy. As mentioned else where, this is the most important differential diagnosis of amoebic liver abscess in our country endoscopy has helped us in majority (though not all) of the patients to get the answer.

The following is the modified technique of peritonescopy as followed by Udwadia.

Technique
Local anaesthesia was given in conjunction with l.V. Diazepam in doses varying from 2 to 10 mgs. Local anaesthesia permitted the procedure even in bad risk cases and had the added advantage of a conscious and co-operative patient who can change positions easily. Pneumoperitoneum was created using a de Verres spring loaded needle. The gas used to create the pneumoperitoneum was atmospheric air introduced with a formalin sterilised hand-pump. No disadvantage was found in the use of air and the pump was preferred to an insufflator.
Creating the pneumoperitoneum is not incidental to peritoneoscopy but is an important part of the procedure. Percussion to determine uniform and complete obliteration of liver dullness is carried out as the pneumoperitoneum is being created. With the exception of the inferior surface, abscesses over the rest of the surface of the liver, very often, become adherent to the parietes, with the result that careful percussion (with alteration in the patients' position for posterior percussion) will elicit an area where the pneumoperitoneum has not obliterated the liver dullness. This is a very important indication of underlying amoebic liver abscess.
The trocar and telescope are then introduced through an infraumbilical midline stab incision. By altering the volume of the pneumoperitoneum tilting the operation table up or down, right or left lateral, and with the use of the fore-oblique telescope the entire surface of the left lobe of the liver, and the entire surface of the right lobe with the exception of the postero-medial surface are visualised. Thus, peritoneoscope is often referred to as "the mirror image of the liver".
In 32 cases of endoscopically diagnosed amoebic liver abscess, Udwadia¹⁰ noted that fourteen were right lobe inferior surface abscesses medial to the gall bladder, five were infero-lateral abscesses lateral to the gall bladder, five were supero-posterior, while eight involved the inferior surface of the liver in the region of the falciform ligament (junctional abscess) and two involved the left lobe. These cases were referred from other units and thus did not include the junctional and flank abscesses of my series where liver scan was already done and endoscopy was resorted to confirm the diagnosis.
The superior and lateral surface abscesses had become adherent to the neighbouring parietes (Fig. 43) and the presence of an underlying abscess could be confirmed by endoscopic palpation of the adjacent liver surface for underlying softening with the help of a probe. Under peritoneoscopic control these abscesses can be aspirated by inserting the aspiration needle through the area of adhesions preventing any peritoneal contamination by pus.
The endoscopic picture of inferior surface abscess was as follows. The Iiver surface overlying the abscess was adherent to omentum in most cases and to the transverse colon in two cases of junctional abscess. Liver softening could be confirmed by the probe and aspiration was carried out under endoscopic control by guiding the needle through an area of healthy liver tissue which acted as a tampon preventing escape of pus into the peritoneal cavity. In three junctional and two left lobe abscesses, the lesion was adherent to the anterior abdominal wall through which route the abscess was aspirated.
Of the three false positive cases, laparotomy revealed that one was a large necrotic metastasis on the postero-superior surface, other was an infected hydatid cyst and the last was a small perigastric abscess with adhesions to the junctional area of the liver. Thus, occasionally difficulties have arisen even at peritoneoscopy for confirming the etiology of the mass.
Though there were no complications in any of these cases peritoneoscopy is an invasive procedure and should only be done where specific indications exist. Most cases of amoebic liver abscess should have the benefit of a liver scan, and peritoneoscopy is not indicated in them. However, when the diagnosis is in doubt or when there is an upper abdominal lump suspected to be due to inferior surface abscess, peritoneoscopy is safe and an invaluable adjunct in the diagnosis and management of amoebic liver abscess.

References

1. Kelling, G. Uber die Besichtigung der Speiserohre und des Magens mit biegsamen Instrumenten Ges. dtsch. Naturf Arzte, 1901, 73, 119.
2. Jacobaeus, 11 C, Uber die Moglichkeit, die Zytoskopie bei Untersuchungen seroser Hohlungen anzuwenden, Munch, med. Wschr., 1910, 57, 2090.
3. Korbsch, R. Die Laparoskopie nach lacobaeus, Berliner Wschr. 1921, 58, 696.
4. Kalk, H. Erfahrungen mit der Laparoskopie, Z. klin. Med., 1929, 111, 303.
5. Kalk, H. Indikationsstellung und Cefahrenmomente bei der Laparoskopie, Dtsch. med Wschr., 1935, 61, 1831.
6. Ruddock, J C, Peritoneoscopy, Surg. Gyn. Obst., 1937, 65, 623.
7. Kapoor, O P. Udwadia, T E, et al, Paper read at XVlIIth Annual Conference of Indian Society of Gastroenterology, Manipal, Nov. 1977.
8. Kapoor, O P. Udwadia, T E, et al, Paper read at Ist Annual Conference of Society of Gastrointestinal Endoscopy of India, Bombay, Jan. 1978.
9. Kapoor, O P. Mistry, C J. Paper read at IXth Annual Conference of Society of Nuclear Medicine of India, Trivandrum, Oct. 1977.
10. Udwadia, T E, Paper presented at 1st Conference of Tropical Surgery at Bombay, 1975.