Introduction

Laparoscopic cholecystectomy (LC) is being in practice for more than thirty years. Success depends on multiple factors including: anatomical variations, pathologic changes in the gallbladder (GB) and surrounding tissue, pre-operative interventions attempted, the individual surgeon’s skill and finally patient co-morbidities. The procedure learning curve is not proportionate to the yet high incidence of related complications. This situation mandates review of the surgical technique and the prevailing anatomical description.

Review of anatomical topography and contemporary situation of LC

In 1891, Calot defined a triangle shaped anatomic area formed by the common bile duct medially, the cystic duct laterally and the cystic artery superiorly.1 The triangle has been modified but in the current usage Calot’s triangle is generally considered to be the triangular area with an upper boundary formed by the inferior margin of the right lobe of the liver, rather than the cystic artery. As Calot’s triangle includes the arterial and ductal structures and their variations it is considered of cardinal importance in the safe conduct of LC. The cystic artery is found in the triangle in 90 % of cases and the right hepatic artery in 82 %; when present, an accessory right hepatic artery is located in Calot’s triangle in 95 % of cases and accessory bile ducts in 91 %. The cystic duct is mostly ranging between 2–4 cm in length, in 20 % of cases shorter than 2 cm and extremely rare to be absent. In comparison Budde Moosman has described another comparable description that did not gain popularity.2 – 6 So, Calot’s triangle is an inconstant field capacitating a wondering cystic artery, that is recommended to be viewed and dissected by the SAGES safe LC strategy; does it sound safe?

A more recent interpretation of this important anatomic area, it is more appropriately referred to as “the hepatoduodenal ligament” rather than Calot’s triangle. This is defined as the double layered roll of the extreme right side of the lesser omentum. It contains the common bile duct, hepatic artery and portal vein as well as the lymph nodes. The anatomical situation and variations of structures in the hepatoduodenal ligament and hepatic hilum are a legacy of their embryological development. The vascular, biliary, and lymphatic structures contribute to the functioning of blood and bile flow as well as lymph drainage of the liver. Connective tissue, fatty tissue, and the peritoneal sheet are enveloping the underlying structures. Their position, shape, and relation to neighbouring structures influence the situation during operative procedures. The cystic artery origin is variable, as is the number; and its recognition is important for safe cholecystectomy. Venous drainage of the gallbladder goes into the portal system of adjacent segments IV and V and influences the spread of gallbladder pathology. There are some surgically important variations in the course and distribution of bile ducts and arteries in the hepatoduodenal ligament. The biliary anatomical variations significantly influence the incidence of biliary injury during LC. The arterial supply of extrahepatic bile ducts is delicate and variable and should be considered when trying to prevent ischemic injuries to the bile ducts. Inflammation and the combination of inflammation and anatomical variation are thought to contribute to a dangerous situation in regard to eventual injury to the biliary and vascular structures during LC.7

Laparoscopic cholecystectomy is a major advance in the management of GB disease since the introduction by Mouret in 1987. This advance has not been cost free, and the peer reviewed surgical literature has called attention to major complications associated with LC. All related complications in the vicinity field are related mostly to failure to appreciate common anatomic relations due to a narrow field of vision, two dimensional view, inappropriate depth perception, difficulty in judging size and non-tactile dissection; are all factors. Anatomy of the extra-hepatic bile ducts, cystic artery and right hepatic artery is intimately related to LC complications. Age above 60, male gender, gallbladder wall thicker than 4–5 mm, a contracted gallbladder and operating during acute cholecystitis are all risk factors for the conversion of LC to open surgery. Although LC is recommended as standard treatment for acute cholecystitis, up to 10 % conversion to open cholecystectomy is required, that is still perceived as a "complication".8 , 9

Anatomical variations of the extrahepatic biliary tree are frequently seen and may cause challenging conditions for surgeons. The shape of the inferior surface of the quadrate lobe is defining the cystic/common bile duct angulation. The median cystic/ common bile duct angle was found to be 43°, 37° and 26° for square, rectangular and pyramidal quadrate shapes, respectively. As the angle for pyramidal-shaped quadrate lobes are narrower than that for rectangular or square lobes; this is considered a challenge in achieving the “critical view of safety” (CVS). There is an inverse relationship between the shape ratio and the cystic/bile duct angle.10 More over Buddingh et al. have concluded that CVS is conclusive in no more than 27 % of cases.5

Stating that the standard accepted for assessment of biliary anatomy up till now is by working within the CVS and also by intraoperative cholangiography (IOC) as needed, is very much doubtful and invites verification. Exploring Calot’s triangle with its inconstant anatomical boundaries harbors the risk of injury to such items. The incidence of bile duct injury during LC is two to four times higher than that in open cholecystectomy. The reported incidence 0.3 % of bile duct injury during LC has not decreased over time despite increasing experience with the procedure. The lengths of the common hepatic duct and the cystic duct vary inversely with the length of the common bile duct.11 , 12

The higher incidence of bile duct injury following LC is primarily due to a combination of two factors: (1) failure to provide adequate exposure of the critical structures within the hepatoduodenal ligament and (2) failure to accurately define the anatomy of the hepatoduodenal ligament. The majority of bile duct injuries should be avoidable by a greater appreciation of the anatomy of the biliary tree as viewed through the laparoscope.13 Davidoff and associates have described a variation in the classic biliary injury with division of the cystic duct adjacent to the common bile duct with distal clips placed on the common bile duct.14 Hunter has emphasized the importance of lateral or downward traction of the infundibulum of the GB to place the cystic duct perpendicular to the common duct and diminish the risk of mistaking the common duct for the cystic duct.15

Andell and associates have studied the anatomical variations of the cystic artery in a large series. The cystic artery originated typically from the right hepatic artery (79.02 %) and was found in the hepatobiliary triangle in only 5427 of 6661 (81.5 %) cases. In the rest 18.5 % of cases, clinically important cystic artery variations are (1) the cystic artery located anterior to the common hepatic duct or common bile duct found in 485 of 2704 (17.9 %) and 228 of 4202 (5.4 %) of cases, respectively, (2) the cystic artery located inferior to the cystic duct found in 38 of 770 (4.9 %) of cases, (3) short cystic arteries found in 98 of 1037 (9.5 %) cases and (4) multiple cystic arteries found in (8.9 %) of cases. These variations are common in the general population and can lead to inadvertent injury of biliary ducts or aberrant vessels.16

Rashid and co-workers have explored the cystic artery during LC and documented one or more cystic duct branches from the cystic artery that joins the cystic duct near its distal end in 161 patients (91.47 %) that may cause troublesome bleeding during dissection of Calor’s triangle. In addition they reported that the cystic artery is mostly joining the neck of the GB at any point around the 360 degrees circumference as a fixed course point.17

The suggested six strategies by the Society of the American Gastrointestinal and Endoscopic Surgeons “SAGES” safe cholecystectomy program depend mostly on exploration of Calot’s triangle and CVS viewing. The program does not give any dissection choice other than visualization of the CVS and gives any alternative in case of obscured CVS but to call a more experienced surgeon to operate.18 , 19

In conclusion there is still missing concept including a reliable anatomical topography, surgical view recommendation and safe LC technique without conversion to open surgery unnecessarily.

Study concept: Proposing a reliable anatomical topography and dissection technique for LC

In the era of laparoscopic surgery, the appreciation of the three dimensional anatomy is extremely important. The traditional two dimensional anatomy used to apply should no longer be accepted as basis for laparoscopic surgery. The third dimension is liable to variable appreciation by the surgeon as the field view differs according to the distortion created by site, degree and direction of traction on tissue to be dissected. The cystic artery is almost constantly joining the GB distal infundibulum regardless its variable proximal course, origin or branches to the GB and cystic duct. This point is extremely important as it is uniquely the only constant anatomical point in the field. This point is defined by the author as the point of control of the GB pedicle, including both the cystic duct and artery. So considering this point as the “Critical Point of Surgical Control” (CPSC) of the GB; is the corner stone of this technique. Identification of CPSC of the GB would make a technical difference in LC, being the extreme proximal-most end point of dissection starting from the GB fundus. So describing an anatomical topography to apply during LC procedure starting dissection from the GB fundus to the CPSC point is the basis for the recommended technical change. (Fig. 1)

Fig. 1
figure 1

Anatomical topography of the LC surgical field. 1- Gall bladder, 2- Critical Point of Surgical Control “CPSC”: the junction between GB neck and cystic duct, 3- Common bile duct, 4- Hepatoduodenal ligament part of the hepatogastroduodenal ligament, 5- Foramen of Winslow, 6- Common hepatic duct, 7- Right hepatic duct, 8- Left hepatic duct, 9- Inferior surface of the liver reflected cephalad, 10- Stomach &11- Duodenum

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Starting with identification of the GB fundus, dissecting the plane between the GB and its hepatic bed, reaching the landmark of CPSC at the GB distal infundibulum, stop dissection at this point and applying an endo-loop to control the hilum of the GB including the cystic duct and the cystic blood supply whatever it is without dissection. Usage of the reliable endo-loop substituting the traditional endo-clip that might be incriminated to include un-identified structures that varies according to the variant anatomy prevailing in each case. Such limit of dissection prevents the risk of potential injury to the anatomically unpredictable structures of the hepatoduodenal ligament. Moreover it avoids ischemic injury to biliary ducts.

So describing a surgical technique not exploring Calot’s triangle, not requiring CVS visualization, not requiring IOC, avoiding metallic clipping of cystic structures and in addition minimizing both complications and conversion to open surgery are all prospects of the standard technique needed. All these aspects constitute a potentially ideal LC technique that could be applied empirically even in the most difficult surgical situations. This paper is trying to achieve and test such a technique.

Materials and Methods

Institutional Surgical Research Board has reviewed and approved the study plan and technique. The study is fully approved from both biomedical and ethical aspects.

Between January 2012 and August 2015, 525 cases were presented with acute cholecystitis and diagnosis was achieved by clinical, laboratory and sonographic examination. Any patient presented with obstructive jaundice was investigated by magnetic resonance cholangio-pancreatico-graphy (MRCP) and further endoscopic retrograde cholangio-pancreatico-graphy (ERCP) and biliary system clearance prior to scheduling for LC. No cholecystostomy procedure was done to any of the study cases. No single case was excluded from the study once included.

Definitions

  1. 1

    “Antegrade dissection of the GB” (AGD) means starting dissection with Calot’s triangle and control of the cystic duct and vessels then finally separation of the GB from the hepatic bed.

  2. 2

    “Retrograde dissection of the GB” (RGD) means starting dissection by separation of GB fundus from hepatic bed and proceed proximally towards GB neck, defining CPSC of the GB and finally control the cystic duct and vessels within the GB mesentery collectively without further dissection.

The proposed technique has taken in consideration “SAGES” safe cholecystectomy program recommendations only to classify the study sample intraoperatively into two groups as follows:

  1. Group A

    where AGD of the GB is possible as CVS exposure is potentially possible but RGD is the applied option.

  2. Group B

    where AGD of the GB is unsafe as CVS exposure is potentially impossible and RGD is mandatory.

So both groups were operated applying RGD of the GB with comparison of clinical presentation, operative and post-operative follow up data between both groups.

Surgical technique applied in the study is defined in the following steps

(Figs. 2,3,4,5,6,7 and 8)

Fig. 2
figure 2

Starting dissection by GB fundus separation from the hepatic bed using combination of diathermy hook and suction irrigation probe

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Fig. 3
figure 3

Progress of dissection of GB body from hepatic bed

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Fig. 4
figure 4

Hemostasis of hepatic bed by applying a piece of gauze

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Fig. 5
figure 5

Progress of dissection using gauze blunt dissection till level of GB neck

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Fig. 6
figure 6

Progress of dissection till the level of CPSC of the GB

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Fig. 7
figure 7

Endo-loop is introduced around the GB fundus and is pushed down towards the CPSC of the GB

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Fig. 8
figure 8

Sliding the endo-loop down to the level of CPSC of the GB

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  1. 1.

    Veress needle is inserted in the periumbilical region and pneumoperitoneum is completed.

  2. 2.

    The periumbilical port is introduced and the scope is passed through.

  3. 3.

    The other three ports in the epigastrium, right subcostal in midclavicular line and right anterior axillary line laterally are all introduced.

  4. 4.

    Anatomical identification of the liver and GB is achieved.

  5. 5.

    According to CVS potential achievement cases were classified into either Group A or B. Case study inclusion criteria for Group B are defined as:

    1. a)

      Inability to reflect the liver cephalad and so the GB due to fatty liver or dense adhesions around the inferior surface of the liver and GB.

    2. b)

      Dense adhesions around the GB and inability to visualize Calot’s triangle and CVS achievement is impossible or hazardous.

    3. c)

      Dense adhesions intra-abdominally from generalized abdominal pathology, or previous surgical intervention.

    4. d)

      Gangrenous GB that is friable to handle.

    5. e)

      No case had cholecystostomy prior to LC.

  6. 6.

    RGD of the GB starting with the fundus first separating from the liver bed by pushing the liver edge towards the abdominal wall and the GB fundus intra- abdominally. Getting this dissection plane through irrigation/suction, hook diathermy or by blunt dissection pushing a piece of gauze held on top of endo-clench forceps. Dissection is completed till the level of GB distal infundibulum just at the junction with the cystic duct is reached; identified as the CPSC. In some cases the GB wall is extremely fibrotic and adherent to the liver surface. In such a case the liver surface in prone to injury and bleeding. Bleeding control using gauze compression with patience, diathermy coagulation while suction tip is nearby and hemostat application are all means of bleeding control.

  7. 7.

    Finally after complete GB separation from the GB hepatic fossa, further hemostasis is achieved by diathermy ball applied to the liver bed, suction irrigation of blood from Morrison’s pouch and if hemostasis is not complete, a piece of gauze is laid in the hepatic bed down in Morrison’s pouch deep to the field of dissection to lighten the resolution of the surgical field view. This would keep the field clear for the next step of GB bud control.

  8. 8.

    Polydioxanone (PDS) endo-loop is introduced through the epigastric port, passed around the fundus and pushed down to the level of CPSC and tightened to include the GB infundibulum - cystic duct junction and the mesentery of the GB away from the CBD. No metal clips were ever used in any of the cases.

  9. 9.

    Another endo-loop is applied in the same way and tightened one Centemetre distal to the previously applied endo-loop around the GB infundibulum.

  10. 10.

    The GB infundibulum is divided by scissors between the two endo-loops.

  11. 11.

    The GB is extracted from the epigastric port within or without an endo-bag.

  12. 12.

    Hemostasis is completed, gauze pieces are extracted and liver bed is padded with surgical fibrillar absorbable hemostat (oxidized regenerated cellulose) and closed vacume drain is applied whenever there is suspicion in liver bed hemostasis.

  13. 13.

    Peritoneal cavity is deflated of gas and port sites are sutured and dressed.

Follow up of patients

The duration of follow up post operatively ranged between one and fourteen days till normalization of clinical and biochemical data. Complete blood picture, and serum bilirubin and liver enzyme assays were repeated until value normalization. Abdominal ultra-sonography follow up in cases with operative related drop of hemoglobin were achieved within the first 48 hours. Out patients were followed up for a maximum duration of two weeks in the out-patient clinic and by phone.

Results

All clinical data related to study sample has been tabulated (Tables 1, 2 and 3). Data is formulated in comparison between the two groups of the study.

Table 1 Patients’ per-operative clinical data
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Table 2 Patients’ operative clinical data
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Table 3 Patients’ follow up clinical data
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The study has recruited all clinical criteria variants; the easy and difficult ones as divided in two groups. No patient had cholecystostomy procedure prior to LC.

No patient was excluded once registered in the study what so ever was the clinical situation. Being non-selective regarding patient recruitment, this has been reflected on the study results. Pre-operative patients’ clinical data is showed in Table 1.

Conditions that constituted dissection difficulty has been named in nine identities as faced in the study sample. Moreover, the frequency of gathering more than one identity per patient has been documented as well. This is presented to appreciate the challenge facing the operating surgeon regarding the technique and the post-operative implementations. In all cases regardless the degree of technical difficulty the RGD technique has been applied with no single case of conversion to open technique.

As the GB blood supply is not controlled until the very late end of the surgical technique, the chance of bleeding is higher than in the AGD method. Such cases presented 36 patients of the total sample in which controllable more than usual bleeding was faced. Control of such difficulty needs cool attitude and confidence from the operating surgeon. All the 36 patients had a peritoneal drain to rule out re-bleeding post-operatively. Five patients in Group A and thirty one patients in Group B had had a drain. The operative time in Group B used to be relatively longer approaching two hours and upon progressing in practice this tended to be around one hour as presented in Table 2.

The needed packed red cell (PRC) blood transfusion intra-operatively and following surgery intended to keep patient’s hemoglobin between 11–12 gm percent. This target implied transfusion to five patients in Group A and 31 patients in Group B. This has conformed a percentage of 3.5 and 8.1 respectively in each group. Abdominal ultra-sonographic examination was mandatory in four patients in Group B during the first 48 hours to evaluate intra-abdominal collection volume. Such volume was below 90 ml in all the four cases and needed no further intervention than the persisting intra-abdominal drainage tube. Normalization time for liver function tests (serum bilirubin; total and differentials, alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase enzymes) post-operatively was around one day in Group A and four days in Group B. In the later, the prolonged liver enzyme elevation time is obviously related to the degree of hepatic surgical trauma and bleeding as well. No patient was presented with postoperative jaundice or biliary leakage. Four patients from Group B needed intensive care and mechanical ventilation due to their concomitant restrictive pulmonary disease. No patient needed post-operative MRCP or any sort of intervention. Hospital stay was remarkably longer in Group B until normalization of patients’ clinical and biochemical data achieved. Patients continued on out-patient clinic follow up and phone communication for a maximum duration of two weeks. No patient needed re-hospitalization during the follow up period.

Discussion

Over the last thirty years of practicing LC we are still missing a properly verified topography guiding dissection. Teaching the laparoscopic surgeon defective topography and practicing operative dissection accordingly leads to the possibility of LC complication and conversion to open procedure would be relatively high; as the situation currently is. The unresolved issue regarding description of a safe LC technique; that could be empirically applied on every case regardless the anatomical variation, intra-abdominal situation and clarity of field dissection still exists. Offering safe applicable surgical technique would reduce the need to advanced level of surgical training to achieve the standard LC procedure.

Identifying a prototype topography and defining the magnitude borders of dissection are the basis for a safe LC procedure. Technical obstacles such as; limitation of field of vision, deficient three-dimension anatomical concept and operating according to surgeon’s thought but not vision; all are co-factors sharing the process of imminent operative complication.

The study has divided recruited patients into two groups. Group A; showing the potential of exploring CVS and achieving a traditional cholecystectomy and Group B; showing extremely difficult operative field and CVS achievement is impossible holding high risk of either operative complication, conversion of procedure to open surgery or even both. The study has tried RGD of the GB on both study groups from the very beginning. Applying such a study plan intended to offer the proposed LC technique “an empirical application” on any GB surgery without modification or patient selection as well.

The study has identified all predictors for difficult LC procedure beginning with the epidemiological factors and extending to the anatomical features, variations and anomalies. Identifying the anatomical variant of the quadrate lobe as a landmark for the acute angulation of the cystic / hepatic duct is crucial. On the other hand the new technique guarded dissection of Calot’s triangle or CVS exposure, as they seem to be a technical trap full of complications.

The only point of risk applying RGD detaching the GB from its hepatic bed is that dissection is achieved prior to control of the cystic vessels that might result in more bleeding than with AGD. More over in some cases the plain of dissection might be fibrotic and impossible to define leading to more bleeding than usual. The number of packed red cell (PRC) unit transfusion was relatively higher in Group B patients (8.1 compared to 3.5 %). All these points are directly related to the difficult operative situation and that the technique is delaying control the GB blood supply till the very end of the procedure. Such a higher rate of bleeding and blood transfusion could be appreciated as the price for the technical safety and non-conversion to open technique.

Upon review of literature, no studies have defined RGD technique usage preoperatively nor recruited relatively large sample to collect significant results. Some trials had documented that RGD is associated with lower conversion and complication rates and shorter postoperative hospital stay as compared with conventional AGD LC when used to treat patients with contracted gallbladders and gallstones.20 In one of the biggest series on LC, Kelly has documented that RGD was applied only on 11 out of 1041 patients (1.1 %) does have a role and should be in the armamentarium of even experienced laparoscopic surgeons.21 Gupta and others have documented that rate of conversion to open in the conventional LC group has decreased from 18.75 % (27/144) to 2.08 % (3/144) using RGD.22

Conclusions

The study, up to best knowledge of the author, has the largest patient sample and the only to define application of the RGD technique prospectively and empirically on every recruited patient for LC. The RDG technique has abandoned exploration of Calot’s triangle or CVS visualization and does not need IOC. Instead the technique has adopted the CPSC; the point at which the cystic artery stem or branches join the GB distal infundibulum, and considered this point as the GB pedicle to be controlled. Further proximal dissection in the direction of proximal biliary ducts is avoided. This limitation of dissection has proved applicable on anatomical and pathological variant situations faced during emergency as well as scheduled LC. The proposed topographic concept has defined the hepatoduodenal ligament as the area not to dissect, minimized the factor of surgeon’s skill and reduced the incidence of complication and even conversion to open procedure down to nil. Although “fundus-first” technique is not new, but proper description of the technique, where to dissect and where to stop, rational behind conflict with SAGES recommendations regarding “safe” LC, and finally applying the concept as routine in every LC are all discussed for the first time as proved by review of literature. The author did not use high tech tools in GB dissection such as LigaSure or Harmonic Ultracision to prove applicability of the technique at basic level of hospital equipment. The proposed technique needs further verification through open discussion among endoscopic surgery societies and more over application on wide scale study samples. Critic is invited.

Finally the Author gives his recommendation to a safe LC technique as follows

  1. 1.

    Preoperative biliary investigation and clearance by MRCP +/− ERCP as needed.

  2. 2.

    Use of at least a thirty degree forward oblique viewing telescope.

  3. 3.

    Flexible lateral ports position as implied by the situation per case.

  4. 4.

    Dissection of adhesions around the GB fundus if any.

  5. 5.

    Traction of the fundus of the GB apart from hepatic bed and separation of the GB using hydro-dissection, cautery or blunt gauze dissection as suitable to surgeon.

  6. 6.

    Reaching the “critical point of surgical control” (CPSC) of the GB, dissection is stopped and two PDS endo-loops are applied consequently on the distal GB infundibulum with one cm distance in between.

  7. 7.

    Tissue is cut in between the two endo-loops using endo-scissors.

  8. 8.

    The GB is extirpated directly or within an endo-bag.

  9. 9.

    Hemostasis is achieved and application of absorbable hemostat and closed drain as needed per case.

  10. 10.

    No handling or dissection is attempted to the cystic duct or artery, hepatic or common bile ducts.

  11. 11.

    Suture closure of port sites.

  12. 12.

    Thorough follow up mainly for bleeding and resuscitation of patient as needed.