Keywords

Introduction

Laparoscopic cholecystectomy (LC) has rapidly evolved to be the procedure of choice for management of symptomatic gall stone disease [1]. Initially, the complication rate with LC was high but with technological advancement and increase in the expertise, it has now reached a remarkably low level at 2.0–6.0% [2]. Conversion rate of 7–35% has been reported in literature [3].

Definition of Difficult Gallbladder

What constitutes a difficult laparoscopic cholecystectomy is a subjective definition with authors having described it multifariously. One of the simplest definitions of difficult gallbladder is a procedure with increased surgical risk as compared to standard cholecystectomies [4].

A difficult gallbladder dissection may be due to:

  • Congenital variants in anatomy,

  • Altered pathology for example inflammations and scarring distorting local anatomy,

  • Obscured anatomy due to increased visceral fat and

  • Increased risk of bleeding as seen in cirrhotics.

Difficulty in LC can be measured as follows:

  1. A.

    Postoperative outcome variables/ procedural modifications

  2. B.

    Scoring systems grading various intraoperative findings.

Defining a Difficult Gall Bladder Based on Outcome or Procedural Modification

Most individual studies make their assessment of difficult LC based on outcome variables. Some of the outcome variables used for measuring difficulty of LC are morbidity, mortality, conversion, operative time, postoperative hospital stay, bile leak and iatrogenic injuries. Parameters like operative time, (time taken to dissect gallbladder from liver bed, time taken for Calots dissection, time taken to identify cystic duct), bile or stone spillage, rupture of gallbladder and conversion to open have been suggested as surrogate markers of operative difficulty [3, 5,6,7,8,9]. Others define difficulty with need for modification of procedures like performance of subtotal cholecystectomy, cholecystostomy, fundus first approach or necessity for intraoperative cholangiography [6, 9,10,11]. The problem with outcome-variable oriented classification is that surgeon’s skill becomes a confounding factor.

Defining Difficult Gallbladder Based on Grading and Scoring Systems Using Intraoperative Variables

Grading/scoring systems with intraoperative variables are more objective and have less bias because they are largely independent of operative skills of the surgeon. The earliest attempt to define an objective scoring system to measure intraoperative difficulty was proposed by Cuscheri et al. in 1992 [5] followed by Nassar in 1995 with modification in 1996. The modified Nassar scale has an addition of grade 5 to the original 4 categories (Table 1) [12], based on clinico-radiologic and operative parameters. Randhawa et al. in their attempt to develop a preoperative predictive system stratified difficulty based upon limited intraoperative parameters viz.: time taken, bile spillage, injury to duct/ artery and conversion (Table 2) [7]. In a study using the Delphi technique to define operative difficulty, an elaborate set of intraoperative parameters with precise grading was proposed which were broadly categorized as factors related to inflammation of the gallbladder and intra-abdominal factors unrelated to inflammation. Factors related to inflammation of the gall bladder was further subcategorized into: appearance around the gallbladder, appearance of the Calot’s triangle area, appearance of the gallbladder bed, additional findings of the gallbladder and its surroundings (Table 3) [13].

Table 1 Difficulty grading by operative parameters of gallbladder cystic pedicle and adhesions as proposed by Nassar et al. [12] (Modified Nassar Scale)
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Table 2 Intraoperative criteria used to define difficulty of laparoscopic cholecystectomy by Randhawa and Pujahari [7]
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Table 3 Intraoperative findings that were considered to potentially contribute to surgical difficulty score in mulitinational collaborative study on surgeons using Delphi technique (2017) [13]
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Sugrue et al. graded operative difficulty based on a few intraoperative parameters along with BMI and time taken to identify cystic artery and duct (Table 4) [6]. The cholecystitis severity/difficulty grading of Parkland et al. incorporates an array of intraoperative variables as shown in Table 5) [14]. Classifications based on preoperative and intraoperative parameters to predict outcome related to mortality, morbidity, hospitalization and conversion in the acute/non elective settings are shown in Tables 6 and 7 [15, 16]. A recently proposed preoperative parameter-based risk scoring system to predict Clavien Dindo grade 4, grade 5 complications has been tabulated in Table 8 [17]. Tables 9 and 10 enlists the various preoperative grading scales based upon classified intraoperative difficulty [7, 18].

Table 4 Operative grading system for cholecystitis severity by Sugrue et al. [6]
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Table 5 Parkland grading scale for severity of cholecystitis [14]
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Table 6 Tokyo Guidelines 2018 severity grade for acute cholecystitis [15]
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Table 7 AAST EGS grade descriptions of acute cholecystitis severity [16]
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Table 8 Scoring System to predict Clavien Dindo grade 4/5 complications post cholecystectomy in non elective setting by Burke et al. [17]
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Table 9 Preoperative clinicoradiological risk scoring system proposed by Nassar et al. based upon their intraoperative scoring system post validation in a large dataset (2019) [18]
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Table 10 Scoring system proposed to predict intraoperative difficulty based on preoperative clinico-radiological parameters proposed by Randhawa and Pujahari [7]
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Operative difficulty might be classified as:

  1. I.

    Access related

  2. II.

    Dissection related i.e. dissection of calots/dissection from liver bed

  3. III.

    Extraction related.

Whereas access and extraction related difficulties are commonly encountered in other laparoscopic procedures as well, dissection related challenges unique to a difficult gallbladder are being primarily emphasized in this chapter.

Prediction of Difficult Laparoscopic Cholecystectomy

Prediction of difficult laparoscopic cholecystectomy entails issues which address:

  1. 1.

    Patient selection criteria in acute settings.

  2. 2.

    Patient selection in chronic settings.

  3. 3.

    Use of preoperative predictors related to difficulty as indicated by findings in history, physical examination, biochemical parameters, radiologic studies.

  4. 4.

    Use of intraoperative findings that aid in grading difficulty.

  5. 5.

    Scoring systems as predictors of difficulty and their validation.

  6. 6.

    Treatment recommendations based on severity grading

Patient Selection Criteria in Acute Settings

Guidelines for Patient Selection in Clinically Diagnosed Acute Cholecystitis or Emergency Cholecystectomy

A crucial consideration in performing a safe laparoscopic cholecystectomy lies in appropriate patient selection especially in the context of acute cholecystitis. Acute cholecystitis and emergency/non elective operations have been suggested to be a risk factor for intraoperative difficulty [18].

Age: Age is reported as an independent risk factor for grade 3 and grade 4 Clavien Dindo complications in a large volume study analyzing risk factors for cholecystectomy in non-elective setting [17].

Duration of acute illness: Early laparoscopic cholecystectomy typically performed within 72 h of onset of acute cholecystitis is a reasonably accepted protocol in most centers. Authors evaluating early laparoscopic cholecystectomy in acute cholecystitis i.e., typically performed within 72 h as compared with postponed laparoscopic cholecystectomy performed within 6 days of onset noted a higher rate of subtotal cholecystectomy in the latter group. Performance of surgery after 9 days has been associated with higher rates of subtotal cholecystectomy and conversion [19, 20].

Comorbidities: Presence of comorbidities is a decisive factor in choosing between laparoscopic cholecystectomy and drainage (cholecystostomy) in higher grades of acute cholecystitis as per Tokyo and AAST EGS guidelines [15, 16]. In a study evaluating possible predictors of conversion to subtotal cholecystectomy in acute cholecystitis, it was noted that ASA >3 was an important factor [20].

Palpable tender gallbladder mass: Palpable tender gallbladder mass, has been denoted to be Grade 2 severity in the Tokyo classification (Table 6) [15].

Planned open surgery: A preoperative plan for open surgery has been shown to be an independent predictor of higher risk of postoperative complications after laparoscopic cholecystectomy [17].

Sepsis: Presence of local and generalized sepsis are proposed risk factors for difficult cholecystectomy and post cholecystectomy complications (Tables 6, 7 and 8) [15,16,17].

WBC Count: An elevated WBC count >18,000 has been proposed as a criterion to define grade II severity in acute cholecystitis grading in 2018 Tokyo Guidelines [15].

Albumin: The risk of postoperative complications after non elective cholecystectomy has also been stratified based on preoperative albumin levels with lower levels increasing the risk (Table 8) [17].

Renal function: Low estimated GFR has also been shown to adversely affect outcome in laparoscopic cholecystectomy (Table 8) [17].

Ultrasound (USG):USG which is a very common investigation to detect gall bladder disease has features incorporated in grading of severity of acute cholecystitis, like: (1) Non visualization of the gallbladder, (2) increased wall thickness, (3) pericholecystic fluid, (4) fluid in right upper quadrant, (5) air in biliary tree, (6) abscess formation, (7) free intraperitoneal fluid (generalized), (8) gall stone ileus and (9) cholecystoenteric fistula [16] (Table 7) (Figs. 1 and 2).

Fig. 1
figure 1

Abdominal ultrasound showing pericholecystic fluid

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Fig. 2
figure 2

Abdominal ultrasound showing thick gallbladder wall

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Grade/severity of disease: Grade 3 acute cholecystitis has been a relative contraindication for cholecystectomy in acute cholecystitis, a higher incidence of conversion to open, subtotal cholecystectomy and longer postoperative stay has been noted in these patients though a translation into higher postoperative morbidity or mortality may not be always eminent [10, 19]. The 2018 Tokyo guidelines recommends early cholecystectomy in low-risk patients with mild severity. In high-risk patients or low risk patients with moderate and severe acute cholecystitis treatment in higher centers and cholecystostomy/early preoperative drainage as a bailout option is deemed more appropriate [11]. Table 6 outlines grading of severity of acute cholecystitis as proposed by the 2018 Tokyo guidelines [15]. The guidelines incorporate comorbidity, organ system involvement, features suggestive of localized infection and other operative/non operative parameters. Any of the following organ involvement is classified as grade 3: cardiovascular, respiratory, neurological, renal, hepatic and haematological.

The other widely used classification system to stratify management of cholecystectomy in the emergency setting is the AAST EGS (American Association for the Surgery of Trauma emergency general surgery) grading which incorporates radiologic imaging (CT/US/HIDA), intraoperative and pathology variables (Table 7) [16]. Table 8 enlists risk factors associated with postoperative complications after cholecystectomy in non-elective settings [17].

Magnetic resonance Cholangiopancreatography (MRCP): MRCP findings like thickness of GB around the neck, and disruption of common hepatic duct are proposed as important parameters for predicting conversion or subtotal cholecystectomy [20].

CT Scan: CT scan may be beneficial in detecting gall bladder wall abnormalities/ perforation local sepsis and fluid/biliary collections in right upper quadrant or generalized peritonitis and pus/ air in biliary tract (Table 7) [16].

HIDA Scan (hepatobiliary iminodiacetic acid): Non visualization of gall bladder or radiotracer leak in the right upper quadrant can be important contributory findings in HIDA scan which are considered in AAST EGS classification (Table 7) [16].

Patient Selection in Non-Acute (Chronic) Setting

Unlike acute/acute on chronic setting the chances of encountering difficulty in chronic settings may not be obvious unless attention is paid to subtle characteristics in history and physical examination along with radiologic findings. Prior upper abdominal surgery and cirrhosis were the conventional relative contraindication to laparoscopic cholecystectomy in non-acute settings. However recent studies suggest that laparoscopic cholecystectomy can be safely performed in cirrhotic patients, within Child-Pugh classes A and B, with acceptable morbidity and conversion rate [21].

Despite adherence to the above selection criteria, the surgeon often encounters an unanticipated difficulty during operation. The crux of the issue lies in predicting a difficult laparoscopic cholecystectomy in patients of chronic cholecystitis without any conventional relative contraindications to performing the procedure and relatively normal findings in clinical radiologic and biochemical parameters. Therefore, studies are evolving which throw light on the possible predictors of difficult laparoscopic cholecystectomy and scoring systems thereof.

Possible Preoperative Clinical Predictors/Indicators of Difficult Laparoscopic Cholecystectomy in Elective Setting

There are many risk factors which make laparoscopic cholecystectomy difficult like old age, male sex, obesity, BMI, attacks of acute cholecystitis, number of previous attacks of acute cholecystitis, cholangitis, previous interventions like ERCP stenting, fever, leukocytosis, previous abdominal surgery, clinical signs of acute cholecystitis, and certain ultrasonographic findings i.e. thickened gall bladder wall, distended gallbladder, contracted gallbladder, pericholecystic fluid collection, stone impacted at neck, fixed stones >2 cm, CBD stones and abnormal anatomy. Challenging intraoperative pathologic encounters like dense adhesions at calot’s triangle, fibrotic and contracted gallbladder, acutely inflammed edematous or gangrenous gall bladder and cholecystoenteric and cholecystocholedochal fistula etc. are wary premonitions of a difficult laparoscopic cholecystectomy [6, 9, 12, 13, 22,23,24].

Patient’s history, clinical examination and pre-operative ultrasonographic evaluation can guide a surgeon to some extent in predicting difficulty during surgery. The intraoperative assessment is also important in predicting a difficult gall bladder. Whereas preoperative parameters guide on patient selection and appropriate timing of surgery, intraoperative parameters can guide conversion or use of alternative bailout procedures like subtotal cholecystectomy or drainage. Tables 9 and 10 enlists preoperative factors as predictors of intraoperative difficulty [7, 18].

Parameters Observed in History

Age: Few studies have reported age >50 years as a significant risk factor. Conversion rates are also higher in elderly population. It may be attributed to long duration of symptoms and multiple attacks [18, 25, 26].

Gender: Male Sex is also considered as a risk factor for difficult cholecystectomy. Incidence of conversion to open and mortality is higher in male gender than their female counterparts. Omental and other organ adhesions are more commonly seen in male patients. It may be due to their late presentation; they generally seek medical help after multiple attacks of inflammation. It results in chronic changes which makes surgery more challenging [18, 26,27,28,29,30].

History of hospitalization for acute attacks: Patients who require hospitalization for acute attacks generally carry more chances of difficult laparoscopic cholecystectomy and conversions. They are found to be having dense adhesions at Calot’s triangle and GB fossa. Number of previous attacks, cholangitis and ERCP stenting has significant association with probability of difficult LC [6, 9, 22, 23]. Pain lasting for more than 4 h has been mentioned as a predictive factor of difficult LC [31].

Diabetes Mellitus: DM has been found to be useful predictor of difficult LC in multivariate analysis [31, 32].

Parameters Observed on Clinical Examination

BMI/Obesity: Obesity is considered as a significant risk factor for difficult LC in many studies [7, 33]; though few surgeons have reported that there is no difference in operative time, duration of hospitalization and complication rates [34]. Obese patients pose challenges in achieving pneumoperitoneum, placing subcostal port, retracting fundus of GB and fascial closure. Open trocar placement is also difficult in these patients due to thick layer of fat and pendulous abdomen with umbilicus almost reaching upto pubic symphysis [35]. Also visceral fat associated with obesity may obscure delineation of anatomy. BMI as a surrogate marker of difficult access was considered as a risk factor in the classification proposed by Sugrue et al. (Table 4) [6].

Scar of previous surgery: Upper abdominal scar of previous surgery is also considered as independent prognostic indicator of difficult LC. Omentum and other abdominal organs get adhered to anterior abdominal wall leading to difficulty in trocar placement and visualization of hepatobiliary structures; many surgeons avoid laparoscopic approach in scarred abdomen due to these reasons [3, 26, 27]. Open trocar placement at umbilicus to achieve pneumoperitoneum avoids bowel injury in such cases and allows adhesiolysis. Surgeon should resist eliminating adhesions excessively. Only those adhesions that prevent placement of canulas or interfere with visualization of organ of interest should be lysed [36].

Palpable GB: It is a clinical sign seen in patients having mucocele or empyema. It is difficult to catch hold of the fundus of GB in these cases and aspiration of the contents is often required; it is time consuming and carries risk of spillage. Randhawa et al. has found a significant correlation between palpable GB and difficult LC [7, 37].

Blood parameter: In a study evaluating an array of clinical and biochemical parameters in predicting difficulty of cholecystectomy, elevated CRP and neutrophil lymphocyte ratio were considered as independent predictors of complicated acute cholecystitis in multivariate analysis [38]. A higher WBC count and fibrinogen levels have also been found to be predictors of difficult gallbladders [31, 39]. Bilirubin >2 mg/dl was found to be an important risk predictor in multivariate analysis in a study [32]. However alkaline phosphatase level or liver enzymes have not found to be corroborative in a study [39].

ASA Class: Patients with higher ASA class implying greater comorbidities was a risk factor for anticipated intraoperative difficulty [18]. ASA >3 has been proposed as a predictor of intraoperative difficulty [20].

Parameters in Abdominal Sonography

Thick GB wall: Thickened gall bladder wall is an ultrasonographic finding of acute cholecystitis and it is reported to be a significant factor in many studies [7, 8, 18, 27, 31, 40, 41]. James in 1990, showed that a preoperative gallbladder ultrasound evaluation for symptomatic cholecystitis which documents a thick gallbladder wall [>4 mm] with calculi, is a clinical warning for the laparoscopic surgeon of the potential for a difficult laparoscopic cholecystectomy procedure which may require conversion to an open cholecystectomy [41]. In gallstone disease, the most common reason for wall thickening is acute or chronic pericholecystic inflammatory change (Fig. 2). An acutely inflammed and edematous GB wall may rupture with spillage of infected bile and stones can further limit visualization of the operative field, resulting in a more difficult operation. Chronic inflammatory changes lead to adhesion formations which can pose as an impediment for the detachment of the gallbladder from its bed [37].

Impacted stone at the neck of GB: Patients with a large impacted stone at Hartman’s pouch have higher incidence of operative difficulty (Fig. 3). The large impacted stone can not only predispose to inflammation in the gall bladder and its surroundings but also make grasping difficult. Moreover, impacted stone at neck may predispose to formation of mucocoele, empyema, Mirrizi syndrome and cholecystocholedochal fistula resulting in operative difficulty [8, 13, 42]. Need for increased rate of operative cholangiography in patients with Hartmann’s pouch stone has been noted [42].

Fig. 3
figure 3

Abdominal ultrasonography depicting large gall bladder calculus with posterior acoustic shadowing:Impacted stone at neck

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Distended GB: Various studies have shown that distension of gallbladder [transverse diameter more than 5 cm] is associated with technical difficulty [43].

Small shrunken gallbladder: A small shrunken gallbladder consequent to chronic inflammation can result in hard fibrotic adhesions in region of the cystic artery and duct which are difficult to dissect and can make grasping difficult [31].

Gallbladder wall flow: In a study evaluating sonographic parameters as pointers of difficulty, gallbladder wall flow emerged as a significant factor [8].

Air in gallbladder lumen, wall or biliary tree: Presence of air in gallbladder lumen, wall or biliary tree can be resultant to cholecystoenteric fistula or emphysematous cholecystitis both of which are predicaments of difficulty in AAST EGS classification (Table 7) [16].

CBD stone and CBD diameter: Presence of CBD stones and CBD dilatation >6 mm were found to be independent risk factors predictive of intraoperative difficulty (Fig. 4) [18, 32].

Fig. 4
figure 4

Abdominal ultrasonography showing dilated CBD

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Other parameters (Multiple stones/enlarged liver): Most of the studies did not find any statistical significance between difficulty during LC and the presence of multiple stones [37, 43]. However, gallbladder rupture in patient with multiple stones can lead to spillage of stones, retrieving of which maybe tedious and likewise an abnormal liver anatomy may pose a difficulty [Table 5].

Parameters in Computed Tomography Scan (CT Scan)

Certain parameters in CT-Scan have also been reported to be associated with difficult cholecystectomy viz.: irregular or absent walls, hyperdensity, pericholecystic fluid, hydrops, wall thickening >4 mm [39].

Parameters in MRCP

Signal intensity variations in MRI have been suggested to predict gallbladder wall fibrosis or necrosis. In a study using MRI to evaluate signal intensity in patients with acute cholecystitis it was noted that lower signal intensities were associated with higher rates of conversion to open, prolonged operating time and need for subtotal cholecystectomy in patients of acute cholecystitis [44]. Obscuration near the gallbladder neck, thickness of GB around the neck and disruption of common hepatic duct on MRCP may also be significant predictors of conversion to open or subtotal cholecystectomy [20] (Fig. 5).

Fig. 5
figure 5

MRCP picture showing a distended gall bladder with calculi impacted at its neck with multiple small calculi in Gall bladder. (Image Courtesy: Dr. Munish Guleria, Professor Radiology, Dr. RML Hospital)

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Preoperative Interventions

ERCP: Preoperative interventions like ERCP have been found to be a significant factor indicative of operative difficulty [18]. ERCP particularly if a prior stent has been placed can increase inflammatory adhesions in the region of Calot’s triangle.

Percutaneous cholecystostomy: Prior percutaneous cholecystostomy has also been proposed to increase difficulty of subsequent laparoscopic cholecystectomy [32].

Intraoperative Parameters Used to Grade Difficulty in LC

The intraoperative parameters can largely be classified as

  • Parameters related to disease process (generally independent of surgeon’s ability)

  • Parameters that may be dependent on surgeon’s ability

Parameters Related to Disease Process

Difficulty related to grasping gallbladder: Overdistended/Shrunken gallbladder/Stone impacted at Hartman’s Pouch/ Deep intrahepatic location: An overdistended gallbladder which impedes grasping without decompression also a shrunken contracted gallbladder both contribute to some degree of operative difficulty, besides a large gallbladder size has also been proposed as an impediment [5, 6, 12, 14]. The location of gallbladder deep in the gallbladder fossa has also been cited to mount difficulty in cholecystectomy as also dissection [12,13,14]. Stone impacted at Hartman’s pouch has been proposed as an independent factor predicting difficulty [6, 14, 45]. Figures 6 and 7 shows an intraoperative picture of a difficult gallbladder with stone impacted at the Hartman’s pouch.

Fig. 6
figure 6

Intraoperative picture of gall bladder with calculus impacted at Hartman’s Pouch (yellow arrow) and adhesions in the region of Calots triangle. [Image Courtesy: Dr. Deborshi Sharma]

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Fig. 7
figure 7

Schematic diagram showing frozen callots with stone impacted at infundibulum causing a distended gall bladder

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Extent of adhesions: The extent of adhesions, as also the type of inflammation, around the calots, gall bladder, CBD and adjacent organs like duodenum colon and liver bed are important parameters that impact operative difficulty [5, 6, 12,13,14, 16]. Inability to visualize the gallbladder due to adhesions has been denoted with higher grades/scores in classification systems [6, 14]. Adhesion of Hartman’s pouch with CBD is particularly significant [12]. Contrarily adhesions were not found to be an important factor in prognosticating difficulty grading in a recent study [43]. Figure 8 shows an intraoperative picture of adhesions between liver and bowel obscuring the visibility of gallbladder.

Fig. 8
figure 8

Intraoperative picture: gall bladder obscured due to adhesions between bowel omentumand liver. [Image Courtesy: Dr. Deborshi Sharma]

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Inflammation-Type of adhesion: Flimsy versus Edematous/Fibrotic: The inflammation that pose difficulty can be edematous or fibrotic and scarring. Fibrotic adhesions on the medial aspects especially a fibrotic Calots, evidence of local sepsis or infection, edema in Calots triangle or gallbladder bed and easy friability or bleeding are some of the important measures of operative difficulty [5, 12,13,14]. In an evaluation by surgeons of various intraoperative factors perceived to pose difficulty, diffuse scarring in the Calot’s triangle area was reported to be the amongst the strongest factor contributing to surgical difficulty [13]. Figure 9 shows an inflamed gallbladder with flimsy adhesions and Fig. 10 shows dense adhesions between gallbladder and adjacent duodenum and colon.

Fig. 9
figure 9

Intraoperative picture showing inflammed gall bladder with adhesions around the gallbladder. [Image Courtesy: Dr. Deborshi Sharma]

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Fig. 10
figure 10

Intraoperative picture of dense adhesions of gall bladder with colon and duodenum. [Image Courtesy: Dr. Deborshi Sharma]

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Empyema/necrosis/gangrene/perforation of gallbladder: Empyema, perforation, necrotic or gangrenous gallbladder has been allotted maximum grades/scores in most scoring systems [5, 12,13,14,15,16].

Fistula of the gallbladder: The presence of a cholecystoenteric or cholecystocholedochal fistula was graded with highest points regarding difficulty in one of the scoring systems grading intraoperative parameters [12,13,14, 16]. Figure 11 is an intraoperative picture depicting a shrunken fibrotic gallbladder with cholecystoduodenal fistula.

Fig. 11
figure 11

Intraoperative picture of shrunken gallbladder with cholecystoduodenal fistula (Yellow Arrow). [Image Courtesy: Dr. Deborshi Sharma]

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Abscess formation/non iatrogenic perforation/pericholecystic collection/peritonitis: Pus or biliary collection can be intrahepatic or extrahepatic and may be associated with localized or generalized peritonitis. Pus or biliary collection with localized peritonitis is classified in moderate to severe grades of difficulty in most classification [5, 6, 12,13,14,15,16, 43]. Presence of generalized peritonitis is graded as category 5 (highest category) in AAST EGS Classification (Table 7) [16].

Other non-inflammatory parameters: Excessive visceral fat, altered liver anatomy, anatomical anomalies of gall bladder and cystic duct that is short or absent, or obscured, presence of venous collaterals in cirrhotics are also parameters proposed as impediments to easy cholecystectomy [12,13,14].

Parameters that May be Dependent on Surgeon’s Ability

Intraoperative parameters which have been proposed to grade difficulty but maybe dependent on surgeon’s ability include time taken for operation, injury to biliary duct or vessels, bile or stone spillage and conversion [5,6,7].

Tables 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 enumerates the various preoperative and intraoperative parameters that can point out to a difficulty in laparoscopic cholecystectomy.

Scoring Systems in Grading Difficulty and Their Validation

Scoring systems may incorporate the following types of variables:

  1. (a)

    Preoperative Variables only

  2. (b)

    Intraoperative Variables only

  3. (c)

    Both preoperative and intraoperative variables

Grading Systems Using Preoperative Parameters and their Validation

Nassar et al. devised a preoperative risk scoring systems from extrapolation of data from two large databases (Table 9) [18]. The preoperative scoring system was developed based on intraoperative grading system of difficult laparoscopic cholecystectomy earlier proposed, as enlisted in Table 1 and validated. Increasing age, ASA classification, male gender, diagnosis of CBD stone or cholecystitis, thick-walled gallbladders, CBD dilation, use of pre-operative ERCP and non-elective operations were found to be significant independent predictors of difficult cases (Table 9). The preoperative predictive variables proposed by Randhawa include: age, gender, BMI, history of hospitalization, presence of abdominal scar and palpable gallbladder along with sonographic parameters of wall thickness, pericholecystic fluid and impacted stone at neck as enumerated in Table 10 [7]. The authors used their own grading of intraoperative difficulty as per criteria shown in Table 2 in their analysis for derivation of the above factors. A modified Randhawa classification has been suggested to provide better outcome prediction. In the analysis four factors viz.: cholecystitis, ERCP, thickened wall, contracted gallbladder were indicative for very-difficult laparoscopic cholecystectomy and 3 factors namely: obesity, biliary inflammation or procedure, contracted gallbladder were significant predictors of conversion [46]. Classification of risk of complication based on preoperative scoring system proposed by Burke J et al. (Table 8) is as follows: 0–22 low risk (0.1–4.7%), 23–27 medium risk (5.5–9.9%), 28–43 high risk (11.5–59.4%) [17].

Grading Systems Using Primarily Intraoperative Parameters and their Validation

Different scoring methodologies have been suggested from time to time using overlapping criteria, further adding to the controversy. One of the earliest classification of intraoperative difficulty during cholecystectomy was proposed by Cuscheri in 1992, [5]. Nassar et al. proposed grading of operative difficulty by assessment of gallbladder, cystic duct pedicle and adhesions, Table 1 [12, 18]. A prospective multicenter cohort CholeS study using the above grading system observed that with increase in grades from 1 to 5, the median hospital stay increased from 0 to 4 days, and the 30-day complication rate increased from 7.6 to 24.4% respectively the findings being significant. The Nassar grading scale emerged as an independent predictor of operative time, conversion to open and 30 days complication and reintervention rates. Use of this difficulty scale helps standardization of operative findings and thus is proposed to facilitate audit, training assessment and research across multiple grades of surgeons [47]. In a multinational collaborative study on surgeons using Delphi technique, a consensus was reached on multiple intraoperative parameters as predictors of difficulty. The factors were primarily classified as those related to inflammation in region of gallbladder, calots and gallbladder bed as well as other non-inflammatory intraoperative variables (Table 3). Sugrue M et al. have proposed a G10 operative scoring system to provide simple grading of operative cholecystectomy and predictive need to convert to open cholecystectomy Gallbladder surgery was considered easy if the G10 score <2, moderate (2–4), difficult (5–7) and extreme (8–10) (Table 4). In a study comparing Parkland intraoperative grading scale and AAST EGS scale to assess difficult LC (Table 5), authors observed that the Parkland scale was a superior predictor of operative difficulty, conversion, complication and operative time whereas the Parkland and AAST grades had similar predictive value as regards rates of partial cholecystectomy, readmission, bile leak, and hospital stay [48]. Higher the Parkland grading scale (particularly for grade 4 and above) the greater is the chance of acute cholecystitis and gangrenous cholecystitis. A strong correlation has been noted between Parklands intraoperative grading scale and Tokyo classification for acute cholecystitis. Increasing Parkland grades has been associated with increased CRP levels and higher incidence of acute and gangrenous cholecystitis [49]. An independent validation of AAST EGS system of classification observed good inter-rater reliability for anatomic grading. With increasing AAST EGS grade there was increased incidence of complications, prolonged hospital stay, higher ICU admissions and adverse events. As the above adverse events were noted even in grade 3 patients of the classification, the authors called for a refinement of the classification system [50]. In a comparative validation between Tokyo system and AAST EGS classification the latter was found to outperform the former with respect to disease severity discrimination [51]. In a multicenter validation of Parkland scale, Tokyo guideline classification and the AAST EGS stratification system, Parkland scale was proposed to be better than AAST EGS system and Tokyo classification, with the latter two having similar discriminatory power [52].

Grades of Severity and Suggested Treatment

Table 11 outlines the various treatment options advised classified as per the grades of disease in Parkland scale, Tokyo guidelines and AAST EGS classification [53].

Table 11 Treatment options for various grades of Parkland, Tokyo and AAST EGS classifications [53]
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Utility of the Scoring Systems

Scoring systems can identify patients having high risk for LC and thus help in intimation of patients about the anticipated difficulty that may be encountered, the chances of conversion and further such cases may be scheduled appropriately. These scoring systems may aid in the decision of early conversion to open or opt to bailout options like cholecystostomy or subtotal cholecystectomy when difficulty is encountered. The other probable use of these scoring systems is to select patients more appropriate for trainee surgeons as opposed to more experienced surgeons.

Conclusion

Predicting a difficult laparoscopic cholecystectomy is based upon several patient and surgeon related factors. Various predictive models/scoring systems have been proposed to aid in preoperative and intraoperative prediction of a difficult laparoscopic cholecystectomy which appear promising but needs larger validation. Conversion to OC should not be weighed as a failure of LC but a step toward conduct of safe cholecystectomy in difficult cases.

Summary of different scoring systems for difficult gallbladder tabulated in this chapter

Table 1: proposed by Nassar (1995) and modified (1996)

- intraoperative factors to classify difficulty in LC [12]

Table 2: proposed by Randhawa et al. 2009

- intraoperative factors for difficulty grading in LC [7]

Table 3: a multinational collaborative study on surgeons using Delphi technique 2017

- elaborate and detailed grading of intraoperative factors [13]

Table 4: proposed by Sugrue et al. 2019

- intraoperative factors & few preoperative clinical factors [6]

Table 5: Parkland scale

- Intraoperative factors for grading difficulty of LC [14]

Table 6: 2018 Tokyo guidelines

- severity grading scale for acute cholecystitis: predominantly preoperative factors [15]

Table 7: AAST EGS grading system

- descriptions of acute cholecystitis severity grading: preoperative, intraoperative factors and pathologic correlation [16]

Table 8: Proposed by Burke J et al. 2021

- preoperative risk scoring system in LC as predictor of complications [17]

Table 9: proposed by Nassar et al. 2019

- Preoperative factors predictive of intraoperative difficulty [18]

Table 10: proposed by Randhawa et al. 2009

- preoperative factors which predict intraoperative difficulty [7]

Table 11: Treatment strategies according to grade/severity in parkland scale, Tokyo guidelines, AAST EGS classification (52)

Key Clinical Points

  1. 1.

    Difficult gallbladder has been defined as a procedure with increased surgical risk as compared to standard cholecystectomies.

  2. 2.

    There is need for standardization of criteria to define operative difficulty in laparoscopic cholecystectomy.

  3. 3.

    Various scoring systems have been proposed to grade severity and guide performance of LC as also predict difficulty in acute/non elective as well as chronic/elective settings (Tables 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11).

  4. 4.

    Tokyo guidelines 2018 classifies severity of acute cholecystitis based on presence or absence of organ system failure and local sepsis.

  5. 5.

    Tokyo guidelines recommend early cholecystectomy for low-risk patients with mild severity in acute cholecystitis. In high-risk patients or low risk patients with moderate and severe acute cholecystitis treatment in higher centers and cholecystostomy with drainage is deemed appropriate.

  6. 6.

    The AAST EGS guidelines can help decide on performance of LC in acute/emergency setting and is based upon clinical radiologic and intraoperative criteria along with pathologic correlates.

  7. 7.

    Prediction of difficult laparoscopic cholecystectomy in the setting of chronic cholecystitis requires the judicious consideration of a number of clinical, biochemical, radiological and intraoperative parameters.

  8. 8.

    Earlier difficulty was judged based upon coarse parameters like time taken, injury, conversion and or modification of surgery which could be biased due to experience of operating surgeon.

  9. 9.

    Newer scoring systems classify operative difficulty more precisely and incorporates a larger number of variables (Tables 1, 2, 3, 4, 5, and 7).

  10. 10.

    Scoring systems can be used to:

    1. (a)

      inform patients about the likelihood of difficulty or conversion,

    2. (b)

      aid appropriate scheduling of surgery, viz.: elective vs non elective,

    3. (c)

      objectivize decision on conversion and or process modification example: cholecystostomy/subtotal cholecystectomy,

    4. (d)

      help select suitable cases for trainee surgeons,

    5. (e)

      facilitate precise data recording for research.

  11. 11.

    The Parkland scale, intraoperative scale of Nassar, Tokyo guidelines and AAST EGS scales have been validated in large data sets. Emerging reports on validation of some of these systems are encouraging and wider application in multinational collaborative studies is desirable.