In tropical and developing countries like India, liver abscess is a common problem. It is a diagnostic and therapeutic challenge for the doctors. Untreated cases may lead to mortality. Variable clinical features are seen depending on the type and size of the abscess and its associated complications. A liver abscess is defined as a pus-filled mass in the liver that can develop from injury to the liver or an intra-abdominal infection disseminated from the portal circulation. [1] The majority of these abscesses are pyogenic or amoebic. Parasites and fungi can cause liver abscess rarely. Most amoebic infections are caused by Entamoeba histolytica. Amoebic liver abscess is the most common cause of liver abscess in developing and under developed countries. [2,3,4] Entamoeba histolytica can invade the intestinal mucosa and spread to other organs, especially the liver [5] The incidence of amebic liver abscess (ALA) varies between 3 and 9% of all amoebiasis cases [6] The incidence of Pyogenic liver abscess (PLA) is ranging from 1.1 to 17.6/100,000 individuals.[7] The pyogenic abscesses are usually polymicrobial, but most common are suchas E.coli, Klebsiella, Streptococcus, Staphylococcus, and anaerobes. The severity of these abscesses are because of the high mortality risk in untreated patients. Pleuro pulmonary rupture occurs in 7% to 20% of patients [6] Ruptured liver abscess into thoracic cavity can cause empyema that affects the lung parenchyma and triggers bacterial pneumonia [8, 9] Pleuro pulmonary rupture of liver abscess cases are lethal and timely intervention has a very good prognosis. This study is a review of cases of ruptured liver abscess into thoracic cavity in a tertiary care referral hospital of north India. Our objective is to study the clinical features, investigations, interventions, complications and outcome of these cases in our institute.

This is a retrospective study. Consecutive 70 patients with ruptured liver abscess into thoracic cavity who were referred to CTVS and managed in our department between January 2016 and December 2024 were reviewed. The demographic profile and clinical characteristics were taken into account [table 1]. Pre-operative investigations, modality of management, microbiological data, intra operative findings, post-operative course, complications and follow up were reviewed. [Table 2, 3, 4, 5] Ultrasonography (USG) and computerized tomography scan (CT scan) were the diagnostic investigations. Patients were treated with broad spectrum antibiotics and also as per the culture sensitivity reports. Inter coastal drains (ICD) were placed in most of the patients to drain the pus from the thoracic cavity. Open thoracotomy and drainage of pus along with decortication was done in patients of multi loculated intra thoracic abscess cavity not amenable to ICDs or not resolved by ICD placement and in cases with non expansion of underlying lung. Intercostal drain placement In all the patients ICD was placed in the right thoracic cavity in either 4th or 5th intercoastal space. Before putting the ICD, needle aspiration was done and ICD was placed only if there was any freely aspirable content. Surgical procedure Right postero lateral thoracotomy was performed in indicated cases. Pus and necrotic debris sucked out. Thickened pyemic membrane over the lung parenchyma was removed to facilitate expansion of lung. Repair of any broncho pleural fistula and repair of any diaphragmatic injury were done. Lavage of the thoracic cavity was done. ICD was placed in the thoracic cavity and routine thoracic closure was done in layers. Statistical Analysis Continuous variables are presented as mean± standard deviation and categorical variables as number and percentage

Table-1 (demography and clinical characteristics)( N=70) Male 68 (97%) Female 2(3%) Age (mean ±standard deviation) 41.0 ±10.2 Average duration of symptoms (days) 7 Fever 70 (100%) Pain abdomen and chest 70 (100%) Dyspnea 70 (100%) Cough 60 (86%) Nausea and vomiting 33 (47%) Decreased appetite 59(84%) Distension of abdomen 46(66%) Pedal edema 57(81%) Diabetes 16(23%) History of ATT intake 4(6%) History of alcohol intake 40(57%) In our study group total 70 cases were taken into account. Among them 68(97%) were male and 2(3%) were female. Average age of presentation was 41 years (ranging from 21 year to 73 year). Most of the patients presented to us within 10 days of the onset of the disease. Most common symptoms were fever with pain in chest and abdomen with dyspnea. Other symptoms were nausea, vomiting, decreased appetite. 23% patients were having diabetes mellitus. 57% patients were alchoholic. Table -2 (Investigations) USG ABDOMEN AND CHEST right lobe of liver 68 (97%) both the right and left lobes 2 (3%) ruptured into right thoracic cavity 70(100%) single abscess cavity in liver 65 (92%) multiple abscess cavities in liver 5 (7%) septated pyothorax 10(14.2%) Pyothorax with aspirable content 60 (86%) CECT THORAX Right pyothorax 70(100%) Elevated Right dome of diaphragm 70(100%) Thickening of parietal and visceral pleura 40(57%) Calcification 0 Pus culture and sensitivity Sterile 48 (68.5%) Klebsiella 14(20%) E coli 5 (7.14%) Enterococcus 1(1.4%) Staphylococcus 1(1.4%) Pseudomonas 1(1.4%) USG abdomen and chest x ray was done in all patients. 68 patients (97%) showed involvement of right lobe of liver along with rupture into right thoracic cavity. 65 patients (92%) had a single abscess cavity whether rest 5 cases showed multiple abscess cavity in liver. In USG chest 60 patients (86%) showed pyothorax with aspirable content. In CECT thorax all the patients had right pyothorax and 40 patients (57%) showed thickening of parietal pleura and pyemic membrane along with thickening of visceral pleura. Pus culture and sensitivity of the patients showed most (40 cases i.e around 68.5%) of the culture were sterile for bacterial culture. Among the rest culture positive patient’s klebsiella was the most common causative organism followed by E.coli. Table- 3 (Modality of treatment) N =70 Pigtail in abscess cavity of liver 63(90%) ICD placement and drainage 40 ((57%) ICD placement and drainage followed by thoracotomy and decortication 20 (29%) Thoracotomy and decortication 10(14%) USG guided pigtail catheter placement in liver abscess was done in 63 cases (90%). ICD placement in right thoracic cavity was done in 60 cases (86%). But among them 20 cases (29%) were needed thoracotomy and drainage along with decortication of right lung. The rest 10 cases (14%) that were not amenable to inter coastal drain had undergone thoracotomy with drainage. Surgery was performed in the cases where the inter coastal drain placement was not possible or in cases of failed intercostal tube drainage. Table -4 (Intra operative findings in cases of thoracotomy) (N=30) Thickened parietal and visceral pleura 30 (100%) Broncho pleural fistula 1 (3%) Visible Diaphragmatic rupture site 1(3%) Intra operative complete expansion of lung 28(93.3%) All the patients of thoracotomy were having thickened parietal and visceral pleura. One case had bronchopleural fistula. Complete expansion of lung intra-operatively was found in 28 cases (93.3%). Post operatively complete lung expansion was seen in 29 cases. One patient with damaged lung parenchyma could not achieve complete lung expansion. Average day of ICD removal was around 10 days. Average duration of hospital stay was around 16 days. In 3 cases (10%) surgical site infection was seen. There was one mortality in the study group. No recurrence was documented in the group. Table-5 (Post-operative findings) (N=30) Complete Lung expansion 29 (97%) Average Duration of hospital stay (days) 16 Average day of ICD removal 10 SSI 3(10%) Recurrence 0 Mortality 1(3%)

The liver abscess is a life threatening condition. Etiologically it can be of two types namely amoebic liver abscess and pyogenic liver abscess. Amoebic liver abscess is the most common extra intestinal manifestation of entamoeba hystolytica. Liver abscess has a male preponderance in various studies reviewed similar to our present study (M: F = 34:1). Usually the middle aged people are affected. In our study the average median age is 41 years (ranging from 22 to 70 year). Previous studies also show similar findings. Pain in abdomen and chest, fever, dyspnea and cough were the most common presenting symptoms in cases of ruptured liver abscess into thoracic cavity. Other features are nausea, vomiting and decreased appetite.[10, 11] Previous studies show that alcohol intake was a major risk factor associated with patients of liver abscess. [2] In this study about 57% patients had history of regular alcohol consumption. 16% patients were diabetic in our study group. Previous studies have already established alcoholism and diabetes are the risk factors for the liver abscess.[12, 13] About 97% of our cases had right lobe of liver involvement. Previous studies also showed mostly involvement of right lobe of liver. [14, 15]The right hepatic lobe has a rich blood supply which explains the preponderance. Contrast-enhanced CT can distinguish between necrotic mass and aggressive abscesses. So it can differentiate necrotic tissue from viable tissue. CT is also useful in the identification of various complications associated with liver abscess. CT scan is more helpful than USG to see intrathoracic pathology and condition after rupture into it. It can helpful in determining the thickness of parietal pleura, pyemic membrane, condition of underlying lung parenchyma and any calcification. Both ultrasound and CT are highly sensitive (ultrasound, 85%-95%; CT, 100%) for detecting liver abscess.[16] Amoebic liver abscess is the most common liver abscess. Pyogenic liver abscess are uncommon. So pus culture is mostly sterile. Among the culture positive patients most common causative organism was klebsiella followed by E.coli in our study. Most of the studies showed that most common causative organism is klebsiella.[17,18]Antibiotics were given as the first line of medical management. first antibiotic regimen should consist of piperacillin, tazobactam, or third-generation cephalosporins and metronidazole. The latter has the advantage of partially covering enterococcal infections. [19] Based on available data, combined therapy involving an aminoglycoside and a beta-lactam antibiotic is recommended for individuals with severe infections caused by Klebsiella spp. and hypotension. [20] Along with the medical management Now a days percutaneous drainage of liver abscess is the mainstay of treatment.[ 21, 22, 23,24] So in 63 cases (90%) USG guided pigtail placement in liver abscess was done in our hospital. 7 cases had non aspirable content in liver abscess cavity. In case of ruptured liver abscess into thoracic cavity drainage of both hepatic and pleural collections is needed for better prognosis. Though there is a chance that both the thoracic empyema and hepatic abscess have a communication, but they need to be drained separately. Lee et al reported that empyema drainage alone was not sufficient to attain complete resolution [25] when the medical management and percutaneous drainage fails surgical intervention is indicated. So management of ruptured liver abscess into thoracic cavity cases should be individualized based on the patient. [26] Bronchial communication has been reported to occur in over one-third of thoracic complications [27] In contrast to this study our study group had only one broncho pleural fistula (BPF) case. The pleuro pulmonary rupture is considered less severe than the intra peritoneal rupture. Intra operatively complete expansion of lung was achieved in 28 cases (97%). In one case broncho pleural fistula was present along with necrosis of part of lung parenchyma. So lung was about 70%- 80% expnded intra operatively despite repair of the BPF. In another case the lung parenchyma showed patchy areas of consolidation which lead to partial expansion of lung intra operatively. However complete lung expansion was achieved post operatively in 29 (97%) patients. Average duration of hospital stay was longer because of the complicated nature of the disease. Surgical site infection was seen in 3 patients (10%). there is one mortality in our study group because of septic shock with multi organ dysfunction. There was no recurrence of the disease in the study group. Single center, Retrospective nature and small study population are the limitations of the study. Incidence of rupture of liver abscess into thoracic cavity is less which reflects the low study population.

Liver abscess is mostly common in middle age male population and in developing countries. Alcohol consumption, diabetes mellitus are the risk factors associated with this disease. In India recent advances in interventional radiology, intensive care, use of effective antibiotic therapy along with timely surgical intervention have resulted in a decline in the mortality rates from 24% in earlier series to 1% to 3% in more recent studies.[28] Early diagnosis now a days permits timely intervention leading to marked reduction in mortality and morbidity of liver abscess cases. Pleural empyema secondary to rupture of liver abscess is a rare but potentially lethal complication. Early detection of thoracic empyema is essential to reduce rates of associated mortality and morbidity. Adequate drainage remains the cornerstone of any pus collection management. Multidisciplinary, patient-tailored approach in which combined therapeutic modalities like antimicrobial therapy, percutaneous drainage of pus and last but not the least surgical intervention is necessary for better prognosis. If the lung condition does not improve after thoracic drainage and the size of the liver abscess does not decrease, surgery should be the treatment of choice.

1. Mischnik A, Kern WV, Thimme R. [Pyogenic liver abscess: Changes of Organisms and Consequences for Diagnosis and Therapy]. Dtsch Med Wochenschr. 2017 Jul;142(14):1067-1074. 2. Singh A, Banerjee T, Kumar R, Shukla SK. Prevalence of cases of amebic liver abscess in a tertiary care centre in India: A study on risk factors, associated microflora and strain variation of Entamoeba histolytica. PLoS One 2019; 14: e0214880 [PMID: 30943253 DOI: 10.1371/journal.pone.0214880] 3. Khan R, Hamid S, Abid S, Jafri W, Abbas Z, Islam M, Shah H, Beg S. Predictive factors for early aspiration in liver abscess. World J Gastroenterol 2008; 14: 2089-2093 [PMID: 18395912 DOI: 10.3748/wjg.14.2089] 4. Ghosh S, Sharma S, Gadpayle AK, Gupta HK, Mahajan RK, Sahoo R, Kumar N. Clinical, laboratory, and management profile in patients of liver abscess from northern India. J Trop Med 2014; 2014: 142382 [PMID: 25002869 DOI: 10.1155/2014/142382 5. A.H. Wardhana, D.H. Sawitri, F. Ekawasti, E. Martindah, D. Apritadewi, T. Shibahara, et al., Occurrence and genetic identifications of porcine entamoeba, E. suis and E. polecki, at Tangerang in West Java, Indonesia, Parasitol. Res. 119 (9) (2020) 2983–2990, https://doi.org/10.1007/s00436-020-06806-0 6. S.L. Stanley Jr., Amoebiasis, Lancet (London, England). 361 (9362) (2003) 1025–1034, https://doi.org/10.1016/s0140-6736(03)12830-9. 7. Meddings L, Myers RP, Hubbard J, et al. A population-based study of pyogenic liver abscesses in the united states: incidence, mortality, and temporal trends. Am J Gastroenterol 2010;105:117–24 8. D.N. Amarapurkar, N. Patel, A.D. Amarapurkar, Amoebic liver abscess, J. Hepatol. 39 (2) (2003) 291–292, https://doi.org/10.1016/s0168-8278(03)00235-6.]. 9. S. Martínez, C.S. Restrepo, J.A. Carrillo, S.L. Betancourt, T. Franquet, C. Varon, ´ et al., Thoracic manifestations of tropical parasitic infections: a pictorial review, Radiographics 25 (1) (2005) 135–155, https://doi.org/10.1148/rg.251045043. 10. Ochsner A, DeBakey M, Murray S: Pyogenic abscess of the liver. American Journal of Surgery. 1938, 40:292- 319. 10.1016/S0002-9610(38)90618-X 11. Greenstein AJ, Lowenthal D, Hammer GS, Schaffner F, Aufses AH Jr: Continuing changing patterns of disease in pyogenic liver abscess: a study of 38 patients. Am J Gastroenterol. 1984, 79:217-26. 12. Alberto González-Regueiro J, Moreno-Castañeda L, Uribe M, Carlos Chávez-Tapia N: The role of bile acids in glucose metabolism and their relation with diabetes. Ann Hepatol. 2017, 16 Suppl 1:S15-20. 10.5604/01.3001.0010.5494 13. Jha AK, Jha P, Chaudhary M, et al.: Evaluation of factors associated with complications in amoebic liver abscess in a predominantly toddy-drinking population: a retrospective study of 198 cases. JGH Open. 2019, 3:474-9. 10.1002/jgh3.12183 14. Sharma MP, Dasarathy S, Sushma S, Verma N: Variants of amebic liver abscess. Arch Med Res. 1997, 28 Spec No:272-3]. 15. Serraino C, Elia C, Bracco C, et al. Characteristics and management of pyogenic liver abscess: A European experience. Med (United States). 2018;97(19):e0628. 16. Seeto RK, Rockey DC. Amebic liver abscess: epidemiology, clinical features, and outcome. West J Med 1999; 170: 104- 109 [PMID: 10063397]. 17. Lai HC, Lin CC, Cheng KS, Kao JT, Chou JW, Peng CY, Lai SW, Chen PC, Sung FC. Increased incidence of gastrointestinal cancers among patients with pyogenic liver abscess: a population-based cohort study. Gastroenterology. 2014 Jan;146(1):129-37.e1. [PubMed: 24095786 18. Abbas MT, Khan FY, Muhsin SA, Al-Dehwe B, Abukamar M, Elzouki AN. Epidemiology, Clinical Features and Outcome of Liver Abscess: A single Reference Center Experience in Qatar. Oman Med J. 2014 Jul;29(4):260-3. [PMC free article: PMC4137581] [PubMed: 25170406 19. Liu Y, Wang JY, Jiang W: An increasing prominent disease of Klebsiella pneumoniae liver abscess: etiology, diagnosis, and treatment. Gastroenterol Res Pract. 2013, 2013:258514. 10.1155/2013/258514. 20. Korvick JA, Bryan CS, Farber B, et al.: Prospective observational study of Klebsiella bacteremia in 230 patients: outcome for antibiotic combinations versus monotherapy. Antimicrob Agents Chemother. 1992, 36:2639-44. 10.1128/AAC.36.12.2639]. 21. Priyadarshi RN, Prakash V, Anand U, Kumar P, Jha AK, Kumar R. Ultrasound-guided percutaneous catheter drainage of various types of ruptured amebic liver abscess: a report of 117 cases from a highly endemic zone of India. Abdom Radiol (NY) 2019; 44: 877-885 [PMID: 30361869 DOI: 10.1007/s00261-018-1810-y 22. Hanna RM, Dahniya MH, Badr SS, El-Betagy A. Percutaneous catheter drainage in drug-resistant amoebic liver abscess. Trop Med Int Health 2000; 5: 578-581 [PMID: 10995100 DOI: 10.1046/j.1365-3156.2000.00586.x 23. Ken JG, vanSonnenberg E, Casola G, Christensen R, Polansky AM. Perforated amebic liver abscesses: successful percutaneous treatment. Radiology 1989; 170: 195-197 [PMID: 2909097 DOI: 10.1148/radiology.170.1.2909097 24. Baijal SS, Agarwal DK, Roy S, Choudhuri G. Complex ruptured amebic liver abscesses: the role of percutaneous catheter drainage. Eur J Radiol 1995; 20: 65-67 [PMID: 7556258 DOI: 10.1016/0720-048x(95)00613-u. 25. Lee EJ, Lee KH, Kim JH, et al. A CARE-compliant article: A case report of pleural empyema secondary to Klebsiella pneumoniae liver abscess with a hepatopleural fistula. Medicine (Baltimore). 2020;99(16):e19869 26. Redden MD, Chin TY, van Driel ML. Surgical versus non-surgical management for pleural empyema. Cochrane Database Syst Rev. 2017;2017(3):CD010651 27. Ibarra-Pérez C. Thoracic complications of amebic abscess of the liver: report of 501 cases. Chest 1981; 79: 672-677 [PMID: 7226956 DOI: 10.1378/chest.79.6.672 28. Jindal A, Pandey A, Sharma MK, et al. Management practices and predictors of outcome of liver abscess in adults: a series of 1630 patients from a liver unit. J Clin Exp Hepatol 2021;11:312-320.