Right Hepatic Lobe Hypoplasia and Gangrenous Cholecystitis: Surgical Implications and Case Report

Abstract

Patient: Male, 70-year-old

Final Diagnosis: Congenital hypoplasia of the right hepatic lobe

Symptoms: Sharp epigastric pain

Clinical Procedure: Laparoscopic cholecystectomy

Specialty: Gastroenterology and Hepatology • Surgery

Objective: Rare disease

Background

Hypoplasia of the right hepatic lobe is a rare congenital anomaly often discovered incidentally during imaging or surgery. This anomaly can be challenging during surgery, leading to intraoperative complications. Patient with right hepatic hypoplasia usually live normally without symptoms, but it can be associated with liver cirrhosis, portal hypertension, and gallstones. While the exact pathophysiological relationship between congenital hepatic hypoplasia and cholecystitis remains unclear, a few contributing factors have been proposed. These include mutations in the hepatocyte nuclear factor 1B (HNF1B) transcription, impaired gallbladder function, and gallbladder ischemia due to malposition.

Case Report

A 70-year-old man presented with gangrenous cholecystitis and concurrent hypoplasia of the right hepatic lobe; a combination not previously documented. The patient, initially asymptomatic, presented with sharp epigastric pain and was diagnosed with acute cholecystitis through abdominal ultrasound. However, computed tomography (CT) imaging showed severe hypoplasia of the right liver lobe with associated compensatory hypertrophy of the left lobe in addition to stones in the gallbladder. Despite normal laboratory results, we think that the anomaly delayed the diagnosis until the development of cholecystitis as a complication. The patient underwent a successful laparoscopic cholecystectomy without converting to open surgery.

Conclusions

This case underscores the importance of recognizing anatomical variations when planning surgery. Awareness of right hepatic lobe hypoplasia can aid in timely diagnosis and appropriate management, ultimately reducing surgical risks and complications. Furthermore, we recommend performing CT in case of vague or atypical symptoms of acute cholecystitis, as well as when the gallbladder shows malposition on abdominal ultrasound (US). However, we recommend identifying the anatomical structure during the surgery to avoid complications.

Introduction

Hypoplasia of the right hepatic lobe is an uncommon congenital anomaly occasionally found in conjunction with other abnormalities in the gallbladder, biliary tree, and adjacent organs [1]. These anomalies can pose challenges during surgery and increase the risk of surgical complications. It is generally asymptomatic and is usually an incidental finding on radiological imaging. This anomaly can be associated with liver cirrhosis, portal hypertension, and gallstone formation; when these conditions develop, this anomaly is usually identified incidentally upon investigation [2].

The typical location of the gallbladder is the right upper quadrant. In the case of acute cholecystitis, tenderness is usually in the subcostal or epigastric region. However, as the presence of this anomaly can differ according to the location of the gallbladder, it can alter the typical presentation of symptoms and examination, requiring further investigations like US or CT to confirm the diagnosis [3].

The pathophysiological link between hepatic hypoplasia and cholecystitis remains poorly understood. However, several contributing factors have been proposed. For instance, El-Khairir et al (2016) reported that mutations in the hepatocyte nuclear factor 1B (HNF1B) transcription factor are associated with multisystem disorders, including hepatic hypoplasia and impaired liver function. These abnormalities can result in bile stasis, which can develop into cholecystitis [4]. Additionally, an underdeveloped liver can impair gallbladder contraction, potentially leading to early-onset cholecystitis [5].

Anatomical variation of the gallbladder can delay the diagnosis of cholecystitis and lead to development of its complications. Gangrenous cholecystitis is a well-known complication that causes necrosis of the gallbladder due to vascular insufficiency. Delay of surgery is another factor that can increase the risk of developing gangrenous cholecystitis [6]. The current criterion standard management for acute cholecystitis is laparoscopic cholecystectomy with a possibility of conversion to open cholecystectomy [7]. Several studies report biliary injury during laparoscopic cholecystectomy due to this anatomical variation [8,9]. Here, we describe a unique case of a patient presenting with gangrenous cholecystitis and hypoplasia of the right hepatic lobe. To the best of our knowledge, this is the first documented case demonstrating the co-occurrence of gangrenous cholecystitis and right hepatic lobe hypoplasia.

Case Report

A 70-year-old man presented to the Emergency Department (ED) with sudden-onset sharp epigastric pain that had started the night before. He was known to have hypothyroidism and was on oral treatment, with no other relevant medical or surgical history. The pain was constant since onset, sharp, non-radiating, improving mildly with analgesia, and started after having a fatty meal. On examination, the patient was in discomfort; however, he was vitally stable and was not pale or jaundiced. His abdomen was soft and lax, with epigastric tenderness. Murphy’s sign was negative, and there was no organomegaly.

Laboratory investigations were within normal range, including complete blood count and liver function tests. The white cell count was 10.64 K/mm³ (normal 3.9–9.8 K/mm³), hemoglobin was 16.3 g/dL (normal 13.5–17.6 g/dL), and platelet count was 233 K/mm³ (normal 131–362 K/mm³).

Additional results included total bilirubin level 1 mg/dL (normal 0.3–1.4 mg/dL), direct bilirubin 0.25 mg/dL (normal 0–0.5 mg/dL), aspartate aminotransferase 21 U/L (normal 10–35 U/L), alanine aminotransferase 22 U/L (normal 5–35 U/L), gamma-glutamyl transferase 45 U/L (normal 12–64 U/L), and alkaline phosphatase 97 U/L (normal 40–150 U/L).

An abdominal ultrasound was done and revealed sludge and multiple gallstones, one of which was impacted at the neck of the gallbladder. The gallbladder was minimally distended, associated with minimal wall thickening and a thin rim of pericholecystic fluid, all features suggesting acute cholecystitis. However, the gallbladder was not in its usual anatomical position, as it was visualized more lateral in the right upper quadrant, almost at the level of the anterior axillary line.

An abdominal CT with intravenous contrast was done to rule out any anomalies. The CT showed a gallbladder located at the right dorsal side of the liver, with a stone impacted at its neck (Figure 1). There was severe hypoplasia of the right liver lobe with associated compensatory hypertrophy of the left lobe. In the arterial view, the right hepatic artery was seen originating from the porta hepatis travelling down with an atretic end, possibly going to an atrophied right hepatic lobe (Figure 2). In the venous view, a right hepatic vein could be seen (Figure 3).

Figure 1.

Contrast-enhanced CT shows malposition of the gallbladder and hypoplasia of the right hepatic lobe. AO – aorta; GB – gallbladder; K – kidney; Sp – spleen; St – stomach; L – liver. Arrows indicate the gallbladder is located in the dorsal side of the liver.

Figure 2.

Contrast-enhanced CT, arterial phase. (A) Arrows indicate main branches of the celiac trunk, common hepatic (red arrow) and splenic artery (blue arrow); (B) Arrows indicate branches of the common hepatic artery. Left hepatic artery (red arrow), and right hepatic artery (blue arrow).

Figure 3.

Contrast-enhanced CT, venous phase. (A) Main portal vein (MPV); (B) Left portal vein (LPV) and right portal vein (RPV).

The patient was diagnosed with acute cholecystitis, hospitalized, and scheduled for laparoscopic cholecystectomy. During surgery, he was placed in the usual recommended reverse Trendelenburg position with a slight left tilt. All ports were inserted in a conventional manner: 1 supraumbilical, 1 epigastric, and 2 in the right upper quadrant. The gallbladder was severely inflamed and necrotic, showing signs of gangrenous cholecystitis, with adhesions between the gallbladder and the omentum and small bowel; no right lobe could be visualized, and the gallbladder was at the lateral bed of segment IV (Figure 4). Laparoscopic adhesiolysis was performed using both sharp and blunt dissection, with the aid of energy devices, which facilitated completion of the procedure laparoscopically, avoiding the need for conversion to open surgery. Intraoperatively, anatomical identification was challenging due to the dense adhesions. Therefore, a reverse fundus-first approach was employed, dissecting down to the level of Calot’s triangle to safely identify the biliary structures. Once the anatomy was clearly delineated, the cystic duct and artery were identified, clipped, and dissected. The gallbladder was carefully shaved off the liver bed and excised. The specimen was sent for a histopathological examination. Hemostasis was maintained through the surgery. There were no intraoperative or postoperative complications. The patient was doing well the next day and was discharged home. He came after 1 week for follow-up, and was doing well, with no concerns other than mild pain in the incision area. His follow-up laboratory test results were unremarkable.

Figure 4.

Laparoscopic view (A, B). There is a hypoplasia of the right hepatic lobe and an obvious malposition of the gallbladder, which is located on the dorsal side.

Discussion

Congenital hypoplasia of the right hepatic lobe is a rare anomaly that is asymptomatic and mostly diagnosed incidentally by a CT scan or abdominal ultrasound; most patients, up until their diagnosis, are unaware of their condition [1,2]. The anomaly may be associated with malposition of the gallbladder; therefore, they may not exhibit the typical symptoms of acute cholecystitis. This results in delaying the diagnosis, leading to development of cholecystitis-related complications [3]. Hepatic hypoplasia can also be associated with altered inflammatory response, possibly increasing the risk of developing gangrenous cholecystitis. Additionally, conditions commonly linked to hepatic hypoplasia, such as biliary atresia or cystic fibrosis, can exacerbate these risks by causing chronic bile duct obstruction and recurrent infections [10]. Our patient was unaware of his condition; he was asymptomatic until he developed severe and sharp epigastric pain that prompted him to seek care at the ED, where he was diagnosed with acute cholecystitis along with hypoplasia of the right hepatic lobe upon investigation. Abdominal examination revealed negative Murphy’s sign but epigastric tenderness; the dorsolateral position of the gallbladder could explain this presentation despite having a gangrenous gallbladder.

A 2008 study by Field et al reviewed 13 reports from 1978 to 2005, showing that more than half of the cases were men, and a third of the patients were diagnosed at over 50 years of age, as was our patient, who was 70 years old [9]. When this anomaly is asymptomatic, patients can have normal lives or have tolerable, vague symptoms that can be resolved by taking simple analgesics. A case report by Fujimoto (2019) presented a 92-year-old-man with misleading right lower abdominal pain and was suspected to have acute appendicitis; when a CT was done, he was found to have a normal appendix, but there was an incidental finding of hypogenesis of the right hepatic lobe with signs of acute cholecystitis [3]. The case showed how hepatic hypoplasia can present with a wide range of atypical symptoms, sometimes mimicking appendicitis symptoms. In contrast to our case, which involved sharp epigastric abdominal pain and largely unremarkable laboratory findings, Fujimoto et al’s case showed more misleading symptoms. Additionally, while the gallbladder could not be visualized in their patient, we were able to identify it and found it was in an abnormal position, which prompted further imaging with CT. Notably, both cases had successful outcomes [3].

Our patient’s surgery went very well with the usual port placement and without modification. The good anatomy identification by laparoscopic adhesiolysis and aid of energy devices helped us to complete the procedure without any complications like bleeding or bile leakage. Nevertheless, we would like to call attention to the fact that some cases might need modification of ports or conversion to open surgery due to possible intraoperative difficulty, according to the individual patient’s case. A case report by Inaelli et al (2005) discussed a port modification due to the incidental anomaly finding during surgery, which demonstrated the difficulty of removing the malposition gallbladder [11]. Furthermore, poor anatomy visualization can lead to bleeding or bile leakage. Paik (2013) reported a case of a 76-year-old man with acute cholecystitis with hypoplasia of the right hepatic lobe discovered during laparoscopic cholecystectomy; approaching the gallbladder was complex and the anatomy was poorly identified, which resulted in biliary injury and bleeding, leading to conversion to open surgery [6]. Therefore, we emphasize the importance of having a good anatomic view and identifying the structure correctly during laparoscopy for patients with hepatic hypoplasia. Unfortunately, we did not perform pre- or post-surgery MRI, and to accurately assess the hypoplasia, we recommend performing MRI if there is no contraindication.

Here, we present a case of gangrenous cholecystitis with hypoplasia of the right hepatic lobe. The anomaly might diminish the typical symptoms of acute cholecystitis, which can result in development of cholecystitis complications. Moreover, we encourage physicians who might find it incidentally to inform the patient about this benign anomaly. To the best of our knowledge, this is the first case report of the co-occurrence of gangrenous cholecystitis and hypoplasia of the right liver lobe.

Conclusions

Hypoplasia of the right hepatic lobe is a rare anomaly. Our patient had gangrenous cholecystitis and hypoplasia of the right hepatic lobe. We emphasize the importance of physicians remaining vigilant for unusual presentations of this condition.

We encourage physicians to consider abdominal CT when patients present with vague abdominal pain or atypical symptoms of acute cholecystitis, particularly when the gallbladder’s position is unclear or appears abnormal in abdominal ultrasound. Early identification of the anomaly is crucial for planning and safely performing the procedure without complications. We emphasize the importance of careful intraoperative identification of anatomical structures in the presence of such anomalies to avoid complications like biliary leakage and bleeding.