Modified Laparoscopic Excision of Choledochal Cyst: Technique and Early Results.

BACKGROUND: Choledochal cyst is a common congenital anomaly requiring surgical treatment. Nowadays, laparoscopic excision is the preferred approach. We studied a modification in the classical laparoscopic approach to facilitate the dissection of a cyst.
MATERIALS AND METHODS: A prospective comparative study was done on 42 Type I choledochal cyst children. One group was operated by classical laparoscopic technique, while the other group was operated by modification of classical technique by deliberately opening the cyst wall and dividing the cyst into two hemi-cups, followed by dissection and excision. The intraoperative and postoperative parameters were assessed in both the groups.
RESULTS: The age, gender ratio, clinical presentation, and cyst diameter were comparable in both the groups. There was a significantly higher success rate (95.7% vs. 73.7%, P = 0.042) and lesser time for cyst excision (96.43 ± 12.15 vs. 120.91 ± 17.38 min P < 0.001) in the modified technique when compared to the classical technique. Further in three patients, it was possible to convert the classical procedure to a modified technique and complete the cyst excision. The postoperative outcomes were similar in both the groups.
CONCLUSION: The modified laparoscopic excision shortens the operative time with higher success rate and comparable short-term morbidity vis-a-vis classical laparoscopic technique. Copyright:

INTRODUCTION

Choledochal cysts are one of the most common biliary tract anomalies requiring surgical management in children occurring in 1 out of every 150,000 live births.[1] Type I choledochal cysts account for approximately 50%–80% of all cysts is a fusiform dilation of the extrahepatic biliary tree in the 5-level Todani modification of the Alonso Lej classification.[2] The risk of recurrent bouts of cholangitis and the substantial risk of developing cholangiocarcinoma mandates its complete excision with bilioenteric anastomosis.[3] Gradually, the laparoscopic approach for the management of choledochal cyst has become the gold standard because of advantages such as less pain, better cosmesis, and faster postoperative recovery.[34] The excision of cyst mandates its circumferential dissection before the division is contemplated. Although not so challenging in patients with minimal adhesions and with sufficient laparoscopic expertise, cases with recurrent episodes of cholangitis and dense adhesions between the cyst and peri cystic tissue often pose significant operative challenge, especially in an early phase of laparoscopic learning curve. The important structures which need special attention during dissection are portal vein and hepatic artery. The portal vein lies in close vicinity to the cyst and is prone to injury in such cases.[5]

In children, the space in the abdominal cavity is comparatively smaller than in adults. Hence, in cases with a large cyst, it may be extremely difficult to rotate the cyst sufficiently to obtain good visibility during the posterior dissection of the cyst. It is also difficult to dissect the lower end of the cyst as it hides behind the pancreas. Further, with the lack of haptic feedback in laparoscopic surgery, the dissection of cyst posteriorly from the portal vein may become more difficult.[35] This may be the reason for higher rates of conversion to open procedure and potential for complications during the early phase of the learning curve. To minimize the difficulties of adhesion and injury to the portal vein, a modification of operative technique by opening the cyst wall at the beginning of surgery has been described by some authors.[56] We performed this prospective study with the aim to evaluate the effectiveness of this modified technique for the laparoscopic dissection and excision of the cyst in comparison to classical laparoscopic dissection.

MATERIALS AND METHODS

This study was performed after ethical approval from the Institutional Ethical Board. The prospective comparative study was done from July 2015 to December 2019. All the children with Todani Type I choledochal cyst on Magnetic Resonance Cholangio Pancreatography (MRCP) were enrolled in the study. Data regarding the demography, clinical presentation, number of episodes of cholangitis, biochemical parameters, and cyst size were recorded. The patients with cholangitis based on Tokyo criteria[7] at the time of presentation were managed conservatively with antibiotics and were operated after a gap of at least 3 weeks form the last episode of cholangitis as per our protocol. The patients with persistent clinical or biochemical evidence of cholangitis after 3 weeks were excluded from the study. The patients who failed to give consent were excluded from the study.

The dissection the cyst was performed by either modified technique (Group A) or the classical technique (Group B) based on random allocation to either of the groups by computer-generated numbers. All the cases were operated by a single surgeon VP.[1]

Modified operative technique

The children were placed in reverse Trendelenburg position after induction. Carbon dioxide pneumoperitoneum was developed using a Veress needle with an intra-abdominal pressure depending on the age of the child. In children under the age of ≤1 year, the pressure kept was 6–8 mmHg; in 1–3 years at 8–10 mmHg, and for children >3 years at 10–12 mmHg. We used infraumbilical incision for camera port and 5-mm 30° laparoscope. The second and third ports were placed in the right and left upper quadrants in concordance with the ergonomic principle under camera vision. A fourth port was placed in the right iliac fossa for the traction on the gallbladder. The dissection was started over the most bulging part of the cyst anteriorly. The adhesion over the cyst and peritoneum over this part was teased away to identify the cystic duct junction with the choledochal cyst [Figure 1]. The adhesions around the cystic duct were freed and Calot's triangle was identified and cholecystectomy was done.

Figure 1

Junction of cystic duct & choledochal cyst

The insertion of the cystic duct was used as a landmark (lighthouse) for further dissection. At the level of lighthouse, the choledochal cyst was opened in the center with a transverse stab incision [Figure 2]. After collecting a sample for bile culture, a thorough suction and irrigation was performed, preventing spillage of bile. Once the cyst was opened and drained, the posterior wall of the cyst could be seen. With a visible posterior wall and advancing the cut laterally on both sides, a plane could be developed easily between the cyst and peri cystic structures while remaining close to the cyst wall. The plane was developed in advance of 0.5–1 cm and repeated on both the medial and lateral sides to free the cyst wall from peri cystic tissue, following which the cyst wall was divided [Figure 3].

Figure 2

Transverse incision over choledochal cyst

Figure 3

Cyst wall separated from pericystic tissues

Once the transverse incision was complete, the cyst was divided into two hemi-cups, one superiorly and one inferiorly. At this stage, a choledochodoscopy was performed in the upper and lower portion of the cyst to confirm the anatomy. The cyst was held with a grasper at the mid of its posterior wall and the dissection was continued superiorly toward the hilum and inferiorly toward the pancreas remaining close to the cyst. As the posterior wall was dissected completely free in the center, the whole dissection became under vision without any chance of injury to the portal vein. Inferiorly, the dissection was continued up to the normal common bile duct where the lower end was ligated and divided with absorbable 4/0 suture. Similarly, dissection was performed for the upper portion of the cyst. Superiorly, the cyst was dissected and excised close to the hepatic hilum at the junction between the normal common hepatic duct and dilated cystic wall [Figure 4].

Figure 4

Cyst dissected and excised

After taking out the specimen in two halves, bilioenteric anastomosis was performed by standard Roux-en-Y hepaticojejunostomy. A subhepatic drain was placed through one of the ports.

Classical technique

The patient's preparation, positioning, anesthesia, and pneumoperitoneum creation were essentially the same. With similar port placements as in the modified technique, the dissection was started with dissection of Calot's triangle and the cystic artery and duct were divided. The cyst was dissected in a standard way without opening the cyst. After complete all-around dissection, the cyst was divided superiorly and inferiorly at the level of normal-sized hepatic and common bile duct, respectively. The lower end was closed with 4/0 absorbable suture. Patients who had their cyst wall opened during dissection were proceeded with the modified technique but were not included in the analysis. After cyst excision, a Roux-en-Y hepaticojejunostomy was performed in the standard fashion. A subhepatic drain was placed through one of the ports.

Outcome parameters and statistical analysis

The primary outcome measures of the study were operating time for cyst excision, intraoperative blood loss, and conversion to open procedure rate, and the secondary outcome measures were time to start the oral feed, length of hospital stay, and early complications. The endpoint of the study was 30 days after surgery. Data were analyzed using SPSS 23.0 package (IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY, USA, IBM Corp.). A level of P < 0.05 was considered to be statistically significant.

RESULTS

A total of 47 patients were enrolled in the study [Figure 5]. Five patients were excluded due to ongoing cholangitis (2), previous abdominal surgery (1), and lack of consent to participate in the study (2). Of 42 patients included in the study, 23 were allocated in Group A and 19 in Group B and were eligible for the analysis. Nine children presented with lump and rest 26 patients with cholangitis in the form of intermittent abdominal pain, fever, and jaundice; however, the number of patients presenting with cholangitis and mean number of episodes among patients in two groups were comparable. The mean duration of symptoms before surgery was 2.64 ± 0.84 months in Group A and 3.00 ± 1.18 months in Group B. The age, gender ratio, clinical presentation, and cyst diameter are detailed in Table 1 and were comparable in two groups. The biochemical parameters of the patients at the time of admission are shown in Table 2.

Figure 5

Study plan

Table 1

Demographic characteristic

Parameter	Group A (n=23)	Group B (n=19)	P
Age (years)	6.07±2.40	6.73±2.76	0.412
Gender (male/female)	13/10	11/8	0.928
Duration of complaint (months)	2.64±0.84	3.00±1.18	0.255
Lump	5	4	0.957
Number of patients with cholangitis episodes	14	12	0.879
Mean cholangitis episodes	6.45±3.22	6.66±3.47	0.802
Size of cyst (cm)	6.00±1.66	6.18±2.40	0.776

Table 2

Preoperative biochemical parameters

Parameter	Group A (n=23)	Group B (n=19)	P
Hemoglobin (g %)	11.57±3.22	11.84±3.16	0.786
Total leucocyte count (×103/mm3)	8500±550	8700±540	0.244
Total bilirubin (mg %)	4.2±0.56	4.32±0.48	0.465
AST (IU/L)	24.18±1.48	24.23±0.98	0.900
ALT (IU/L)	15.32±5.11	16.13±5.88	0.635
Albumin (g %)	3.8±0.63	3.9±0.76	0.643
INR	1.12±0.13	1.14±0.11	0.598

AST: Aspartate Aminotransferase, ALT: Alanine aminotransferase, INR: International normalized ratio

Table 3 shows the intraoperative parameters assessed during the study. There were three patients with significant peri cystic adhesions in both the groups. Of 23 patients in Group A, there was only one conversion to open procedure due to severe peri cystic adhesion with failure to progress laparoscopically with a success rate of 95.7%. In Group B, 14 of 19 cysts were successfully excised laparoscopically by the Classical method, while in the remaining five patients, procedure had to be abandoned. Of these five patients, three patients were converted to modified technique due to either accidental opening of cyst or decision to change technique because of nonprogression of the procedure by Classical technique. The remaining two patients were operated by conversion to open procedure. Thus, the success rate of Classical technique (Group B) was 73.1%. With intention-to-treat analysis, the success rate of Group A with the modified technique was significantly higher than the Classical Method (P = 0.042). The mean operative blood loss was 72.86 ± 18.57 and 81.82 ± 31.24 ml in Group A and B, respectively (P = 0.225). Group A had a significantly lesser time for cyst excision compared to Group B (96.43 ± 12.15 min vs. 120.91 ± 17.38 min, P < 0.001). The postoperative parameters measured are shown in Table 4.

Table 3

Intraoperative parameters

Parameter	Group A (n=23)	Group B (n=19)	P
Pericystic adhesions	3	3	0.800
Conversion to open procedure	4.34% (1/23)	10.5% (2/19)	0.44
Success rate of procedure	95.7% (22/23)	73.7% (14/19)	0.042
Mean intraoperative blood loss (ml)	72.86±18.57	81.82±31.24	0.255
Mean time to complete excision (min)	96.43±12.15	120.91±17.38	<0.001

Table 4

Postoperative outcomes and complications

Parameter	Group A (n=23)	Group B (n=19)	P
Postoperative fever	2	3	0.479
Bilioma and abscess	28.5% (4)	9.0 (1)	0.227
Time to start oral feed (days)	4.12±1.23	4.0±0.85	0.720
Length of postoperative stay (days)	7.55±2.45	7.90±2.76	0.665

DISCUSSION

Majority of choledochal cysts are diagnosed in the first decade of life, and complete excision followed by biliary-enteric anastomosis is the standard treatment offered.[89] The laparoscopic approach for operating choledochal cysts was first reported by Farello et al.[10] in a 6-year-old child. Since then, the laparoscopic technique has evolved and widely accepted with acceptable conversion and complication rate.[11] A meta-analysis of retrospective studies published including 408 laparoscopic excisions out of 1016 children with Roux-en-Y Hepaticojejunostomy showed favorable results in terms of shorter length of hospital stay, lesser blood loss, and time to start the oral feed, though at the cost of increased operative time.[3]

The complete excision of the cyst by laparoscopic approach may be extremely difficult in some cases with recurrent cholangitis and resulting in dense inflammation. The most dreaded complication is the injury to the posteriorly lying portal vein which can be fatal in both open and laparoscopic approaches.[12] Modification of leaving behind the posterior wall of the cyst was suggested by Lily to avoid this complication.[13] In laparoscopic surgery, the improved vision is extremely helpful for the dissection of the cyst wall, but the absence of hepatic feedback may be contrary and can increase the chances of portal vein injury, especially during early parts of the learning curve.[14] The complete dissection of a larger cyst is furthermore difficult in children due to limited space. The modification of the early transaction of the choledochal cyst has been described by Jin et al. for open excision of choledochal cyst.[6] A similar modification has also been suggested in laparoscopic excision by a few cases by Palanivelu et al.[5] In our technique, we have limited the initial dissection of the cyst. This limits any blood loss and hence prevents deterioration of overall vision. Further, we proceeded with our dissection alternately on the medial and lateral parts. This is extremely helpful in laparoscopic excision, as there is no haptic feedback. This is also useful in the early identification of any anatomic variation.

The early opening of a cyst is associated with a bile leak. Although there is a theoretical risk of increased chances of infection[15] due to contamination, thorough irrigation and suction has not resulted in any increase in the chance of infection in the postoperative outcome of our patients [Table 4]. The technical modification decreases the operative time and conversion rate compared to the classical laparoscopic method of dissection.

The mean operative time for laparoscopic management of choledochal cyst has been reported from 180 to 290 min in different studies published in the past 10 years.[16171819] We also had an acceptable time for cyst excision, with a mean operative time in Group A of 96.43 ± 12.15 min and in Group B of 120.91 ± 17.38 min (P < 0.001). The early controlled opening of the cyst with described technique resulted in gradual decompression with minimal blood loss. Further, with improved vision and handling of a decompressed cyst in all directions, the visibility and accessibility to the posterior wall was excellent, resulting in lesser operating time. None of the studies published earlier have measured separately the time for the excision of the cyst, which was one of the objectives measured in our study. The mean blood loss has been reported to vary from 30 to 70 ml in different studies which is comparable to the findings in our study.[161720] Although bile spillage seems to cause a messier operative field, we found that elective opening of the cyst with adequate irrigation and suctioning did not allow a significant collection of bile.

The technical modification used in the present study decreases the operative time and conversion rate compared to the classical method [Table 3] of dissection, as detailed in two previous published studies, of which Palanivelu et al.[5] were done with laparoscopic method, while the other was by open technique.[6] Both these studies included adult patients and were retrospective in design. The present study is probably the first prospective comparative design study in children with choledochal cyst using the modified laparoscopic technique and classical technique. The success rate of the procedure defined by the ability to complete excision laparoscopically was 95.7% in Group A and 73.7% in Group B. We also managed to successfully operate two patients, in which the cyst was accidently opened in Classical method, with the Modified technique. In the study by Palanivelu et al., the success rate was 91.5%.[5]

In the postoperative period, two patients in Group A and three patients in Group B had fever. There were a higher number of patients with complication due to surgery in the form of biloma or intraperitoneal abscess formation (n = 4) in Group A compared to 1 patient in Group B, although it was not statistically significant. All these patients were managed by Ultrasonography-guided drainage of collection. The time to start feed and length of postoperative stay were comparable in both the groups [Table 4]. Most of the previously done studies of laparoscopic choledochal cyst excision done in children are retrospective in nature, and the meta-analysis comparing the laparoscopic and open technique has accepted the limitation of these studies in extracting any conclusion due to low power and heterogeneity of data.[3] However, the technical modification used in the present study has not shown any adverse consequence in the early postoperative outcome of the study when compared to the classical technique. The limitations of the study are the small number of patients in each group and the lack of long follow-up data.

CONCLUSION

The modified laparoscopic excision is a safe and effective surgical option for choledochal cyst excision in children with shorter operative time and higher success rate with comparable short-term morbidity compared to the classical laparoscopic technique. This technique can be especially helpful in cases of peri cystic adhesions and in low-output centers or surgeons with limited experience.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.