The present study has emphasized the importance preoperative imaging to classify calot's anatomy while planning re-operation in patients with symptomatic residual gall bladder. If a cystic duct stump is seen classified as type I anatomy, then complete re-excision of the gall bladder should be contemplated, however, if again a sessile gall bladder is seen classified as type II anatomy, then cholecystectomy leaving a small stump of GB on bile duct wall should be undertaken. More so, the present report is the first of its kind to describe de-novo malignancy in the residual GB stump.

Subtotal cholecystectomy is being performed as a damage control operation for a difficult gall bladder. The incidence reported from large series varies from 0.4% to 3%.¹,³,⁵,⁶,⁷,⁸,¹² Although many reports have shown the safety of this procedure,¹,²,¹² but only a few have described the short and long term complications associated with it.³,⁵,⁶ We observed a 10% incidence of biliary fistula in the entire cohort. Jara et al.⁵ in a study of 22 STC, reported 9% incidence of biliary fistula. A study of 191 subtotal cholecystectomies reported 11% incidence of biliary fistula.⁶ On the contrary, another large retrospective study of 93 cases of residual gall bladder reported biliary fistula in 4%.⁸ We found a residual stump of GB in 20 patients; this indirectly suggests prior reconstituting type subtotal cholecystectomy. Leaving a part of diseased GB stump is more likely to give symptoms when compared to long cystic duct stump. Others have also found frequent need for interventions when reconstituting subtotal cholecystectomy was done when compared to fenestrating type.⁶

We reported the recurrence of symptoms after index operation after 3 years. Most of the studies have reported a median time interval in many years after the index operation.⁸,⁹,¹⁰,¹¹,¹³,¹⁴,¹⁵ On the contrary, Palanivelu et al.⁷ reported a mean of 8 months. This probably might be due to the fact that majority of the STC were performed by them and they could have been more aggressive in follow up. Recurrent symptoms may occur as early as 3 months to as late as 40 years.⁷,⁸,⁹,¹⁰,¹¹,¹³,¹⁴,¹⁵ Early recurrence of symptoms is probably related to incomplete removal of stones from GB.

Though STC is considered as a safe procedure, we observed the occurrence of concomitant biliary stricture in one patient where type II anatomy was found subsequently. Patient was symptomatic for stricture and residual GB was an incidental finding. Other studies describing the management of residual gall bladder lithiasis did not report any case of biliary stricture.⁷,⁸,⁹,¹⁰,¹¹,¹³,¹⁴,¹⁵ However, a review of 15 studies on partial cholecystectomy reported one case of biliary stricture.¹² Another recent study on 191 patients of STC reported one case of biliary stricture following reconstituiting type cholecystectomy.⁶ The development of stricture was a delayed event suggesting diathermy injury as the probable mechanism underlying the stricture formation. This can happen as an overzealous attempt to cauterize residual GB mucosa to prevent malignancy in future. The occurrence of fistula after STC is higher, but it does not lead on to stricture formation as the dissection is usually away from the bile duct. We did not observe any stricture in both the patients with bile leaks. Others also did not report any stricture as a consequence of bile leak.³,⁵,⁶,⁸ In view of a higher incidence of bile leak, use of omentum over the STC stump has been advocated.¹⁶

The present series has reported 5% incidence of malignancy in the residual GB stump. Other reports from the west did not find any case of malignancy in the GB stump.¹⁰,¹⁴,¹⁵ This is probably related to a lower incidence of carcinoma GB in those regions. India being an endemic region for the occurrence of GB cancer, the residual at risk GB mucosa left after STC mandates a close follow up for the development of de novo neoplasm. Even studies from India with considerably long follow up after STC did not report any case of malignancy.⁷ Large Indian series on the clinical profile of residual GB did not report any case of malignancy.⁸,¹¹,¹³ This probable might be due to a very small residual mucosa at risk left after STC. On the contrary, Do et al.¹⁷ has reported a case of cystic duct adenocarcinoma 10 years after index cholecystectomy where a long cystic duct stump was left. Occurrence of de-novo malignancy, in the present study indicate the need for surveillance of residual GB mucosa where complete excision was not possible. Diathermy destruction of the residual mucosa can mitigate the risk however, caution should be exercised as an overzealous attempt can lead on to stricture as was observed in the present study.

Although a few studies report successful laparoscopic re-excision,⁷,⁹,¹¹,¹³ but other have reported open procedures in majority.⁸,¹⁰,¹⁵ Singh et al.⁸ in a large study on residual GB reported conversion to open procedure in 19 of the 48 patients in whom laparoscopy was attempted. Another recent study reported conversion to an open procedure in both the patients where laparoscopy was attempted.¹⁰ One of them sustained major biliary injury. Here in lies the importance of imaging based classification in the present study. Whereas, type I anatomy can undergo complete re-excision and laparoscopic approach can be safe in his situation, on the contrary, type II anatomy should be directly subjected to open procedure. One should be prepared to do subtotal cholecystectomy again in this setting. The proposed algorithm also sub-classify type I into two types based on the presence or absence of GB pouch. In the absence of GB pouch, there is a role of endoscopic management. Walsh et al reported successful endoscopic management of 2 patient with cystic duct calculi.¹⁵

Two series have reported iatrogenic bile duct injury¹⁰,¹³ and one has a report of post operative bile collection.⁷ Despite the fact, that reoperation is carried out by an experienced team, the difficult anatomy, puts the bile duct at risk of injury. Getting the preoperative information of calot's anatomy can circumvent this problem. We believe that patients with type II anatomy should be more prone to biliary injury particularly, if complete removal is attempted. No mortality has been reported so far.

Concluding, residual gall bladder can be a significant problem after subtotal cholecystectomy. Only the ones symptomatic need treatment and asymptomatic ones should be kept under surveillance. It is better to classify the calot's anatomy and plan re-operation either by laparoscopic or open approach. Utmost care should be taken to prevent biliary injury.