Paediatric Surgery (Ukraine). 2024. 4(85): 99-110. doi: 10.15574/PS.2024.4(85).99110
Chuklin S. S.¹, Chooklin S. N.¹, Pereyaslov A. A.^2
1St.Paraskeva Medical Center, Lviv, Ukraine
²Danylo Halytsky Lviv National Medical University, Ukraine

For citation: Chuklin SS, Chooklin SN, Pereyaslov AA. (2024). Prediction of difficult laparoscopic cholecystectomy as the principle of improvement of the results of surgery (review). Paediatric Surgery (Ukraine). 4(85): 99-110. doi: 10.15574/PS.2024.4(85).99110.
Article received: Aug 29, 2024. Accepted for publication: Dec 10, 2024.

At present, laparoscopic cholecystectomy (LC) has become the «gold standard» of acute and chronic cholecystitis treatment and one of the frequent operations performed in general surgery. All these complications characterized LC as difficult, however, there is no consensus regarding the definition of the difficulty of LC.
The aim of this review is to find a consistent and reliable system for predicting intraoperative complications to improve outcomes of LC.
Difficult LC (DLC) is defined as the surgical removal of the gallbladder in conditions when changes in the organ itself, adjacent structures, or the patient’s specific condition prevent its smooth, quick, and comfortable removal during surgery. The definition of DLC varies considerably depending on the experience of the surgical team. With the improvement of technique and skills of LC, the criteria of complexity of surgery and choice of «salvage procedure» have changed.
Preoperative prediction of DLC is extremely important for the choice of adequate treatment and decreases the frequency of intra- and postoperative complications. Various preoperative factors, laboratory data, and results of imaging investigation methods, which are connected with cholecystitis, anatomical changes, previous abdominal surgery, surgeon experience, and comorbidities may determine unfavorable outcomes of surgical procedures. Multiple predictive systems (scales), which combine clinical, laboratory data, and imaging parameters were elaborated to improve the accuracy of preoperative identification of DLC, including elective and emergent surgical procedures, merged personal history-related factors with clinical and imaging factors. These models were more useful than considering each significant factor separately.
Another important preoperative factor that determines the outcome of treatment is the stratification of patients in whom conversion is possible.
Conclusions. Various international studies propose preoperative systems of value for solving the problem of DLC. At the same time, it is extremely important to develop a scale adapted to the characteristics of each population to optimize the efforts of surgeons and improve the overall quality of medical and surgical care. With the improvement skills of LC, the markers of difficulty of surgery change influenced on prognostic value of proposed models. The present prospective cohort studies with validated indicators of difficult surgery may suggest further identification of the best systems for predicting the severity of intervention to improve treatment outcomes.
No conflict of interests was declared by the authors.
Keywords: difficult laparoscopic cholecystectomy, prediction, preoperative complexity criteria, predictive criteria of conversion.

REFERENCES

1. AER Fathy El-sayed Darwish, El-Banna AM, Salem A. (2022). Assessment of perioperative predictors of difficult laparoscopic cholecystectomy. Al-Azhar Med J (Surgery). 5(11): 13-30. https://doi.org/10.21608/amj.2022.210627

2. Ahmed SE, Rehman S, Edilbe M et al. (2017). Can neutrophil-lymphocyte ratio predict operators' difficulty in early cholecystectomies; a retrospective cohort study. Ann Emerg Surg. 2(3): 1016. doi: 10.47739/2333-7117/1016.

3. Alexander HC, Bartlett AS, Wells CI et al. (2018). Reporting of complications after laparoscopic cholecystectomy: a systematic review. HPB (Oxford). 20(9): 786-794. https://doi.org/10.1016/j.hpb.2018.03.004; PMid:29650299

4. Al Masri S, Shaib Y, Edelbi M et al. (2018). Predicting conversion from laparoscopic to open cholecystectomy: A single institution retrospective study. World J Surg. 42(8): 2373-2382. https://doi.org/10.1007/s00268-018-4513-1; PMid:29417247

5. Altıner S, Ergüder E, Altınok SH et al. (2023). The role of preoperative ultrasound in predicting conversion from laparoscopic cholecystectomy to open surgery in acute cholecystitis. Ulus Travma Acil Cerrahi Derg. 29(10): 1109-1113. https://doi.org/10.14744/tjtes.2023.45469; PMid:37791445 PMCid:PMC10644075

6. Anees K, Faizan M, Siddiqui SA et al. (2024). Role of C-reactive protein as a predictor of difficult laparoscopic cholecystectomy. Surg Innov. 31(1): 26-32. https://doi.org/10.1177/15533506231212595; PMid:37926929

7. Arone S, Raghunath KJ, Venkatasubramanian R et al. (2022). Role of preoperative ultrasonography findings in predicting difficult laparoscopic cholecystectomy. World J Lap Surg. 15(3): 229-234. doi: 10.5005/jp-journals-10033-1539.

8. Ary Wibowo A, Tri Joko Putra O, Noor Helmi Z et al. (2022). A scoring system to predict difficult laparoscopic cholecystectomy: A five-year cross-sectional study. Minim Invasive Surg. 2022: 3530568. https://doi.org/10.1155/2022/3530568; PMid:36110248 PMCid:PMC9470297

9. Baral S, Thapa N, Chhetri RK. (2020). Validation of a preoperative scoring system to predict difficult laparoscopic cholecystectomy: A Nepalese perspective. Journal of Lumbini Medical College. 8(1): 3-9. https://doi.org/10.22502/jlmc.v8i1.323

10. Bardakçı O, Bahçecioğlu IB, Tatlı F et al. (2023). Can fibrinogen level be a criterion in choosing the treatment option in patients with acute cholecystitis? Eur Rev Med Pharmacol Sci. 27(10): 4504-4509. doi: 10.26355/eurrev_202305_32456.

11. Bhandari TR, Khan SA, Jha JL. (2021). Prediction of difficult laparoscopic cholecystectomy: An observational study. Ann Med Surg (Lond). 72: 103060. https://doi.org/10.1016/j.amsu.2021.103060; PMid:34815866 PMCid:PMC8591467

12. Brunt LM, Deziel DJ, Telem DA, et al. (2020). Safe cholecystectomy multi-society practice guideline and state of the art consensus conference on prevention of bile duct injury during cholecystectomy. Ann Surg. 272(1): 3-23. https://doi.org/10.1097/SLA.0000000000003791; PMid:32404658

13. Chávez KV, Márquez-González H, Aguirre I, Orellana JC. (2018). Prognostic risk factors for conversion in laparoscopic cholecystectomy. Updates Surg. 70(1): 67-72. https://doi.org/10.1007/s13304-017-0494-0; PMid:28980164

14. Chen G, Li M, Cao B et al. (2022). Risk prediction models for difficult cholecystectomy. Wideochir Inne Tech Maloinwazyjne. 17(2): 303-308. https://doi.org/10.5114/wiitm.2022.114539; PMid:35707332 PMCid:PMC9186076

15. Chhaparia S, Dewangan KP, Geddam SR. (2024). Prediction of difficult laparoscopic cholecystectomy on the basis of preoperative ultrasonography assessment. Int Surg J. 11(1): 75-87. https://doi.org/10.18203/2349-2902.isj20233926

16. De'angelis N, Catena F, Memeo R et al. (2021). 2020 WSES guidelines for the detection and management of bile duct injury during cholecystectomy. World J Emerg Surg. 16(1): 30. https://doi.org/10.1186/s13017-021-00369-w; PMid:34112197 PMCid:PMC8190978

17. Di Buono G, Romano G, Galia M et al. (2021). Difficult laparoscopic cholecystectomy and preoperative predictive factors. Sci Rep. 11(1): 2559. https://doi.org/10.1038/s41598-021-81938-6; PMid:33510220 PMCid:PMC7844234

18. Függer R. (2021). Challenging situations in cholecystectomy and strategies to overcome them. Eur Surg. 53:106-113. https://doi.org/10.1007/s10353-020-00687-4

19. Fujinaga A, Hirashita T, Endo Y et al. (2024). Prediction of intraoperative surgical difficulty during laparoscopic cholecystectomy using drip infusion cholangiography with computed tomography. J Hepatobiliary Pancreat Sci. 31(9): 637-646. Epub 2024 Jul 17. https://doi.org/10.1002/jhbp.12044; PMid:39021321

20. Gregori M, Miccini M, Biacchi D et al. (2018). Day case laparoscopic cholecystectomy: Safety and feasibility in obese patients. Int J Surg. 49: 22-26. https://doi.org/10.1016/j.ijsu.2017.11.051; PMid:29233788

21. Guiab K, Evans T, Brigode W et al. (2022). Complications after inpatient laparoscopic cholecystectomy: Effect of surgeon experience, procedure volume, and other surgeon-based characteristics. Am Surg. 88(8): 1798-1804. https://doi.org/10.1177/00031348221084083; PMid:35337194

22. Gupta N, Ranjan G, Arora MP et al. (2013). Validation of a scoring system to predict difficult laparoscopic cholecystectomy. Int J Surg. 11(9): 1002-1006. https://doi.org/10.1016/j.ijsu.2013.05.037; PMid:23751733

23. Gupta V, Abhinav A, Vuthaluru S et al. (2024). The multifaceted impact of gallstones: Understanding complications and management strategies. Cureus. 16(6): e62500. https://doi.org/10.7759/cureus.62500

24. Hayama S, Ohtaka K, Shoji Y et al. (2016). Risk factors for difficult laparoscopic cholecystectomy in acute cholecystitis. JSLS. 20(4): e2016.00065. https://doi.org/10.4293/JSLS.2016.00065; PMid:27807397 PMCid:PMC5081400

25. Hu ASY, Menon R, Gunnarsson R, de Costa A. (2017). Risk factors for conversion of laparoscopic cholecystectomy to open surgery – A systematic literature review of 30 studies. Am J Surg. 214(5): 920-930. https://doi.org/10.1016/j.amjsurg.2017.07.029; PMid:28739121

26. Ibrahim Y, Radwan RW, Abdullah AAN et al. (2019). A retrospective and prospective study to develop a pre-operative difficulty score for laparoscopic cholecystectomy. J Gastrointest Surg. 23(4): 690-695. https://doi.org/10.1007/s11605-018-3821-y; PMid:29845574

27. Iwashita Y, Hibi T, Ohyama T et al. (2017) An opportunity in difficulty: Japan-Korea-Taiwan expert Delphi consensus on surgical difficulty during laparoscopic cholecystectomy. J Hepatobiliary Pancreat Sci. 24(4): 191-198. https://doi.org/10.1002/jhbp.440; PMid:28196311

28. Jalil T, Adibi A, Mahmoudieh M, Keleidari B. (2020). Could preoperative sonographic criteria predict the difficulty of laparoscopic cholecystectomy? J Res Med Sci. 25: 57. https://doi.org/10.4103/jrms.JRMS_345_19; PMid:33088294 PMCid:PMC7554442

29. Karim ST, Chakravarti S, Jain A et al. (2022). Difficult laparoscopic cholecystectomy predictors and its significance: Our experience. J West Afr Coll Surg. 12(4): 56-63. https://doi.org/10.4103/jwas.jwas_162_22; PMid:36590783 PMCid:PMC9802589

30. Kumar A, Chabra A, Bhushan B. (2017). Evaluation of various pre-operative parameters for prediction of difficult laparoscopic cholecystectomy. J Adv Med Dent Scie Res. 5(3): 91-95. doi: 10.21276/jamdsr.2017.5.3.21.

31. Kumar V, Baderiya VK. (2019). Assessment of preoperative patient factors in early prediction of difficult laparoscopic cholecystectomy: A single institution study. Int J Surg Sci. 3(4): 223-225. https://doi.org/10.33545/surgery.2019.v3.i4d.245

32. Kumawat S, Agarwal l, Yadav A. (2022). An observational study on prediction of difficulties during cholecystectomy in cases of cholelithiasis by preoperative ultrasonography. Basrah J Surg. 28(2): 27-33. https://doi.org/10.33762/bsurg.2022.176624

33. Kurata Y, Hayano K, Ichinose M et al. (2021). Preoperative prediction of difficult laparoscopic cholecystectomy based on diffusion-weighted magnetic resonance imaging. Asian J Endosc Surg. 14(3): 520-528. https://doi.org/10.1111/ases.12911; PMid:33393228

34. Labbad C, Vivas L. (2023). Realization of preoperative score for the prediction of difficult cholecystectomy. Rev Venez Cir. 76(1): 59-64. https://doi.org/10.48104/RVC.2023.76.1.12

35. Lucocq J, Scollay J, Patil P. (2022). Elective laparoscopic cholecystectomy: recurrent biliary admissions predispose to difficult cholecystectomy. Surg Endosc. 36(9): 6403-6409. https://doi.org/10.1007/s00464-021-08986-x; PMid:35024925 PMCid:PMC9402724

36. Maehira H, Kawasaki M, Itoh A et al. (2017). Prediction of difficult laparoscopic cholecystectomy for acute cholecystitis. J Surg Res. 216: 143-148. https://doi.org/10.1016/j.jss.2017.05.008; PMid:28807199

37. Magnano San Lio R, Barchitta M, Maugeri A et al. (2022). Preoperative risk factors for conversion from laparoscopic to open cholecystectomy: A systematic review and meta-analysis. Int J Environ Res Public Health. 20(1): 408. https://doi.org/10.3390/ijerph20010408; PMid:36612732 PMCid:PMC9819914

38. Mahmood F, Akingboye A, Malam Y et al. (2021). Complicated acute cholecystitis: The role of C-reactive protein and neutrophil-lymphocyte ratio as predictive markers of severity. Cureus. 13(2): e13592. https://doi.org/10.7759/cureus.13592

39. Majumder A, Altieri MS, Brunt LM. (2020). How do I do it: laparoscopic cholecystectomy. Ann Laparosc Endosc Surg. 5: 15. https://doi.org/10.21037/ales.2020.02.06

40. Manuel-Vázquez A, Latorre-Fragua R, Alcázar C et al. (2022). Reaching a consensus on the definition of "difficult" cholecystectomy among Spanish experts. A Delphi project. A qualitative study. Int J Surg. 102: 106649. https://doi.org/10.1016/j.ijsu.2022.106649; PMid:35525412

41. Martellotto S, Dohan A, Pocard M. (2020). Evaluation of the CT Scan as the first examination for the diagnosis and therapeutic strategy for acute cholecystitis. World J Surg. 44(6): 1779-1789. https://doi.org/10.1007/s00268-020-05404-6; PMid:32030439

42. Micić D, Stanković S, Lalić N et al. (2018). Prognostic value of preoperative neutrophil-to-lymphocyte ratio for prediction of severe cholecystitis. J Med Biochem. 37(2): 121-127. https://doi.org/10.1515/jomb-2017-0063

43. Missori G, Serra F, Gelmini R. (2022). A narrative review about difficult laparoscopic cholecystectomy: technical tips. Laparosc Surg. 6: 24. https://doi.org/10.21037/ls-22-16

44. Miura da Costa K, Saxena AK. (2021, Feb). Complications in pediatric laparoscopic cholecystectomy: systematic review. Updates Surg. 73(1): 69-74. Epub 2020 Sep 17. https://doi.org/10.1007/s13304-020-00888-2; PMid:32939742

45. Nakazawa A, Akamatsu N, Miyata Y et al. (2020). Usefulness of preoperative drip infusion cholangiography with computed tomography for predicting surgical difficulty during laparoscopic cholecystectomy. J Hepatobiliary Pancreat Sci. 27(6): 315-323. https://doi.org/10.1002/jhbp.718; PMid:31971340

46. Nassar AHM, Hodson J, Ng HJ et al. (2020). Predicting the difficult laparoscopic cholecystectomy: development and validation of a pre-operative risk score using an objective operative difficulty grading system. Surg Endosc. 34(10): 4549-4561. https://doi.org/10.1007/s00464-019-07244-5; PMid:31732855

47. Ohya H, Maeda A, Takayama Y et al. (2022). Preoperative risk factors for technical difficulty in emergent laparoscopic cholecystectomy for acute cholecystitis. Asian J Endosc Surg. 15(1): 82-89. https://doi.org/10.1111/ases.12969; PMid:34291878

48. Onoe S, Maeda A, Takayama Y et al. (2017) A preoperative predictive scoring system to predict the ability to achieve the critical view of safety during laparoscopic cholecystectomy for acute cholecystitis. HPB (Oxford). 19(5): 406-410. https://doi.org/10.1016/j.hpb.2016.12.013; PMid:28117229

49. Orabi A, Di Mauro D, Njere I, et al. (2021). Can preoperative characteristics predict the outcomes of laparoscopic cholecystectomy? J Laparoendosc Adv Surg Tech A. 32(5): 532-537. https://doi.org/10.1089/lap.2021.0398; PMid:34357804

50. Panni RZ, Strasberg SM. (2018). Preoperative predictors of conversion as indicators of local inflammation in acute cholecystitis: strategies for future studies to develop quantitative predictors. J Hepatobiliary Pancreat Sci. 25(1): 101-108. https://doi.org/10.1002/jhbp.493; PMid:28755511 PMCid:PMC5933877

51. Paul S, Khataniar H, Ck A, Rao HK. (2022). Preoperative scoring system validation and analysis of associated risk factors in predicting difficult laparoscopic cholecystectomy in patients with acute calculous cholecystitis: A prospective observational study. Turk J Surg. 38(4): 375-381. https://doi.org/10.47717/turkjsurg.2022.5816; PMid:36875278 PMCid:PMC9979552

52. Priyanka T, Sandeep B, Ayyar SM. (2024). Correlation of preoperative ultrasonographic criteria with intra operative difficulties of laparoscopic cholecystectomy and the possibility of conversion to open cholecystectomy. Indian J Applied Res. 14(02): 72-74. https://doi.org/10.36106/ijar

53. Pucher PH, Brunt LM, Davies N et al. (2018). Outcome trends and safety measures after 30 years of laparoscopic cholecystectomy: a systematic review and pooled data analysis. Surg Endosc. 32(5): 2175-2183. https://doi.org/10.1007/s00464-017-5974-2; PMid:29556977 PMCid:PMC5897463

54. Ramírez-Giraldo C, Alvarado-Valenzuela K, Isaza-Restrepo A, Navarro-Alean J. (2022). Predicting the difficult laparoscopic cholecystectomy based on a preoperative scale. Updates Surg. 74(3): 969-977. https://doi.org/10.1007/s13304-021-01216-y; PMid:35122205 PMCid:PMC9213361

55. Ramírez-Giraldo C, Isaza-Restrepo A, Conde Monroy D et al. (2023). What is the best score for predicting difficult laparoscopic cholecystectomy? A diagnostic trial study. Int J Surg. 109(7): 1871-1879. https://doi.org/10.1097/JS9.0000000000000354; PMid:37288543 PMCid:PMC10389651

56. Randhawa JS, Pujahari AK. (2009). Preoperative prediction of difficult lap chole: a scoring method. Indian J Surg. 71(4): 198-201. https://doi.org/10.1007/s12262-009-0055-y; PMid:23133154 PMCid:PMC3452633

57. Rauf UHA, Malik MUR, Saleem O et al. (2024). Exploring gallbladder radiological parameters for predicting difficulty in laparoscopic cholecystectomy. Biol Clin Sci Res J. 2024: 885. https://doi.org/10.54112/bcsrj.v2024i1.885

58. Raza M, Venkata RM. (2019). Predicting difficulty in laparoscopic cholecystectomy preoperatively using a scoring system. Int Surg J. 6(3): 957-962. https://doi.org/10.18203/2349-2902.isj20190831

59. Rice CP, Vaishnavi KB, Chao C et al. (2019). Operative complications and economic outcomes of cholecystectomy for acute cholecystitis. World J Gastroenterol. 25(48): 6916-6927. https://doi.org/10.3748/wjg.v25.i48.6916; PMid:31908395 PMCid:PMC6938729

60. Room H, Wood A, Ji C et al. (2022). Performance of ultrasound in the diagnosis of cholecystitis: not so (ultra)sound? Ann R Coll Surg Engl. 104(9): 655-660. https://doi.org/10.1308/rcsann.2021.0322; PMid:35175883 PMCid:PMC9685908

61. Rothman PJ, Burcharth J, Pommergaard HC et al. (2016) Preoperative risk factors for conversion of laparoscopic cholecystectomy to open surgery – A systematic review and meta-analysis of observational studies. Dig Surg. 33(5): 414-423. https://doi.org/10.1159/000445505; PMid:27160289

62. Saad MR, Kabbash M, Yassen, A et al. (2024). Preoperative predictive factors of difficult laparoscopic cholecystectomy. Egypt J Surg. 43(1): 56-62. https://doi.org/10.4103/ejs.ejs_239_23

63. Sasaki A, Sakata K, Nakano K et al. (2022). Maximum diameter of the gallbladder determined presurgically using computed tomography as a risk factor for difficult emergency laparoscopic cholecystectomy in patients with mild to moderate acute cholecystitis. Surg Laparosc Endosc Percutan Tech. 32(5): 523-527. https://doi.org/10.1097/SLE.0000000000001093; PMid:36130716

64. Schuster KM, O'Connor R, Cripps M et al. (2021). Multicenter validation of the American Association for the Surgery of Trauma grading scale for acute cholecystitis. J Trauma Acute Care Surg. 90(1):87-96. https://doi.org/10.1097/TA.0000000000002901; PMid:33332782

65. Serrano-González R, Rivero Y, Hernandez-Velasquez A et al. (2024). Predicting difficulty in laparoscopic cholecystectomies: An evaluation of the Labbad-Vivas score and its correlation with the Parkland Grading Scale. Cureus. 16(3): e56185. https://doi.org/10.7759/cureus.56185; PMid:38618440 PMCid:PMC11015945

66. Shelke V, Jat RS, A Dadoria, Dubey R. (2024). Laparoscopic cholecystectomy-correlation of pre operative with intra operative factors associated with difficult cases. JPTCP. 31(2): 740-745. https://doi.org/10.53555/jptcp.v31i2.4483

67. Siddiqui MA, Rizvi SAA, Sartaj S et al. (2017). A standardized ultrasound scoring system for preoperative prediction of difficult laparoscopic cholecystectomy. J Med Ultrasound. 25(4): 227-231. https://doi.org/10.1016/j.jmu.2017.09.001; PMid:30065497 PMCid:PMC6029324

68. Stanisic V, Milicevic M, Kocev N, Stanisic B. (2020). A prospective cohort study for prediction of difficult laparoscopic cholecystectomy. Ann Med Surg (Lond). 60: 728-733. https://doi.org/10.1016/j.amsu.2020.11.082; PMid:33425342 PMCid:PMC7779950

69. Stoica PL, Serban D, Bratu DG et al. (2024). Predictive factors for difficult laparoscopic cholecystectomies in acute cholecystitis. Diagnostics (Basel). 14(3): 346. https://doi.org/10.3390/diagnostics14030346; PMid:38337862 PMCid:PMC10855974

70. STRATA Collaborative and CholeS Collaborative. (2024) External validation of the CholeS conversion from laparoscopic to open cholecystectomy (CLOC) risk score in Aotearoa New Zealand: a validation study. ANZ J Surg. 94(6): 1108-1113. https://doi.org/10.1111/ans.18921; PMid:38525949

71. Teerawiwatchai C, Polprative J, Rattanachueskul K, Thomtong R. (2024). Pre-operative score development: Predicting difficulty in elective laparoscopic cholecystectomy. J Health Sci Med Res. 42(2): e2023994. https://doi.org/10.31584/jhsmr.2023994

72. Teoh AYB, Leung CH, Tam PTH et al. (2021). EUS-guided gallbladder drainage versus laparoscopic cholecystectomy for acute cholecystitis: a propensity score analysis with 1-year follow-up data. Gastrointest Endosc. 93(3): 577-583. https://doi.org/10.1016/j.gie.2020.06.066; PMid:32615177

73. Tongyoo A, Chotiyasilp P, Sriussadaporn E et al. (2021). The pre-operative predictive model for difficult elective laparoscopic cholecystectomy: A modification. Asian J Surg. 44(4): 656-661. https://doi.org/10.1016/j.asjsur.2020.11.018; PMid:33349555

74. Tongyoo A, Liwattanakun A, Sriussadaporn E et al. (2023). The modification of a preoperative scoring system to predict difficult elective laparoscopic cholecystectomy. J Laparoendosc Adv Surg Tech A. 33(3): 269-275. https://doi.org/10.1089/lap.2022.0407; PMid:36445743 PMCid:PMC9997034

75. Toro A, Teodoro M, Khan M et al. (2021). Subtotal cholecystectomy for difficult acute cholecystitis: how to finalize safely by laparoscopy-a systematic review. World J Emerg Surg. 16(1): 45. https://doi.org/10.1186/s13017-021-00392-x; PMid:34496916 PMCid:PMC8424983

76. Trehan M, Mangotra V, Singh J et. (2023). Evaluation of preoperative s alcoring system for predicting difficult laparoscopic cholecystectomy. J Appl Basic Med Res. 13(1): 10-15. https://doi.org/10.4103/ijabmr.ijabmr_553_22; PMid:37266522 PMCid:PMC10230522

77. Utsumi M, Inagaki M, Kitada K et al. (2023). C-reactive protein-to-albumin ratio predicts conversion from laparoscopic to open cholecystectomy in acute cholecystitis. In Vivo. 37(2): 887-893. https://doi.org/10.21873/invivo.13157; PMid:36881091 PMCid:PMC10026666

78. Veerank N, Togale MD. (2018). Validation of a scoring system to predict difficult laparoscopic cholecystectomy: A one-year cross-sectional study. J West Afr Coll Surg. 8(1): 23-39.

79. Vivek MA, Augustine AJ, Rao R. (2014). A comprehensive predictive scoring method for difficult laparoscopic cholecystectomy. J Minim Access Surg. 10(2): 62-67. https://doi.org/10.4103/0972-9941.129947; PMid:24761077 PMCid:PMC3996733

80. Vohra RS, Spreadborough P, Johnstone M, et al. (2015). Protocol for a multicentre, prospective, population-based cohort study of variation in practice of cholecystectomy and surgical outcomes (The CholeS study). BMJ Open. 5(1): e006399. https://doi.org/10.1136/bmjopen-2014-006399; PMid:25582453 PMCid:PMC4298090

81. Wakabayashi G, Iwashita Y, Hibi T et al. (2018). Tokyo Guidelines 2018: surgical management of acute cholecystitis: safe steps in laparoscopic cholecystectomy for acute cholecystitis (with videos). J Hepatobiliary Pancreat Sci. 25(1): 73-86. https://doi.org/10.1002/jhbp.517; PMid:29095575

82. Wennmacker SZ, Bhimani N, van Dijk AH et al. (2019). Predicting operative difficulty of laparoscopic cholecystectomy in patients with acute biliary presentations. ANZ J Surg. 89(11): 1451-1456. https://doi.org/10.1111/ans.15493; PMid:31642165 PMCid:PMC6899702

83. Wertz JR, Lopez JM, Olson D, Thompson WM. (2018). Comparing the diagnostic accuracy of ultrasound and CT in evaluating acute cholecystitis. AJR Am J Roentgenol. 211(2): W92-W97. https://doi.org/10.2214/AJR.17.18884; PMid:29702020 PMCid:PMC6082629

84. Yang TF, Guo L, Wang Q. (2014). Evaluation of preoperative risk factor for converting laparoscopic to open cholecystectomy: A meta-analysis. Hepatogastroenterology. 61(132): 958-965.