Our findings demonstrate that selective patients with massive, symptomatic hepatomegaly from PLD benefit from operative intervention. Specifically, we have shown that given at least relative sectorial sparing, hepatic resection with cyst fenestration of the hepatic remnant can be performed with acceptable mortality, prompt and durable symptom relief, and maintained liver function. Although morbidity is significant, once resolved, clinical performance status improves or normalizes. Hepatic resection with cyst fenestration can be considered for most PLD patients with massive hepatomegaly and symptoms sufficiently severe to justify a surgical intervention. Cyst aspiration with sclerosis or cyst fenestration alone and liver transplantation, though effective in selected patients, are less broadly applicable.
Most patients with PLD are asymptomatic and do not require operative intervention.1
Severely (and in some patients moderate) symptomatic hepatomegaly from PLD is an indication for operation with the implicit aim of reducing hepatic volume. Importantly, we believe that symptoms must significantly alter clinical performance status before operative intervention is undertaken. As a result of our clinical experience, we have developed criteria for operative procedure selection. Selection for each procedure is dependent on the degree of symptoms, distribution of hepatic cysts, volume of noncystic or relatively preserved parenchyma, and vascular anatomy of preserved liver. For patient selection, detailed preoperative assessment is critical. Imaging should clearly detail the portal and hepatic venous anatomy of the anticipated sectoral remnant and the IVC. Magnetic resonance angiography can be helpful in this determination. For this purpose, we classified patients with normal liver function according to clinical and radiographic cross-sectional findings into 4 groups (, ). In general, hepatic resection with cyst fenestration is considered feasible if preoperative evaluation confirms at least single sectoral preservation. Liver transplantation is indicated in the absence of such preservation. Cyst fenestration alone is considered only in patients with large dominant cysts mainly in the anterior hepatic segments. Percutaneous cyst aspiration with or without application of sclerosing agents or selective hepatic artery embolization has limited application in patients with PLD.1,9
For most patients with symptomatic, massive hepatomegaly, partial hepatectomy with cyst fenestration of the hepatic remnant has been more broadly applicable than liver transplantation. Hepatic resection has been successful providing that at least one hepatic sector is relatively spared of cystic replacement with concurrent preservation of the majority of that sectoral parenchyma and that the afferent and efferent sectoral vasculature is patent to assure adequate liver reserve.
Classification of PLD With Suggested Treatment in Patients With Normal Liver Function*
FIGURE 2 Classification of PLD on preoperative computed tomography scan: Left, Typical findings for type B PLD; Middle, Type C PLD with patent iso-sectoral portal and hepatic vein and relatively preserved parenchymal sector; Right, Type D PLD with absence of preserved (more ...)
The choice between hepatic resection with remnant cyst fenestration and liver transplantation can be difficult. The former operative approach implies residual hepatic cysts with eventual, though indolent, progression, whereas the latter approach obviates any residual cysts but requires lifelong immunosuppression. Liver graft allocation is difficult for patients with PLD because symptoms rather than liver failure are the usual indications for transplantation. Both operations may be confounded by the need for renal transplantation which is unrelated to the presentation of the hepatic disease. Extending hepatectomy, to avoid a predominantly cystic remnant, risks liver failure and dictates consideration of liver transplantation. It is important to emphasize surgical experience with major hepatic resections and transplantation and multidisciplinary institutional support in offering the full extent of a tailored treatment. Both resection and transplantation are technically demanding and peri-operative care is complex. We believe referral to a tertiary center with an experienced team of surgeons, hepatologists, and nephrologists is preferable for optimal patient management. Specifically, minimal operative treatment in a highly symptomatic patient who needs extensive intervention will inevitably result in treatment failure, will potentially compromise further treatment, and should be avoided.
The technique for hepatic resection in patients with PLD differs from that in patients without PLD. Several key points warrant comment. The polycystic liver is not only large, but rigid. Consequently, mobility is decreased and access to vascular supply more difficult. In our study, the average preoperative liver volume was 6695 ± 442 cm3
, nearly 6-times greater than the average liver volume of 1100 ± 190 cm3
in healthy patients with noncystic, noncirrhotic livers10,11
; emphasizing the massive degree of hepatomegaly seen in patients with PLD who require operative intervention. Both, exposure and mobilization are facilitated by fenestration of selected cysts. Cysts should be fenestrated centrally to avoid vessels within the intervening septa. Lymphatic vessels near the hilum and within the hepatic ligaments are frequently dilated and should be ligated. Once the hilum is exposed, the lobar hepatic artery, portal vein, and bile duct are isolated and divided before parenchymal transection. Hepatic venous exposure before transection is rarely possible and division is undertaken only after completion of the parenchymal dissection. Fenestration of cysts along the transection plane is essential for division of the liver. We have found the ultrasonic surgical aspirator useful because it facilitates transection of islands of normal liver and rapidly aspirates cyst fluid after division of the cyst wall thus permitting concurrent use of electrocautery for hemostasis. The ultrasonic surgical aspirator, however, does disrupt small bile ducts adjacent to vessels and suture ligatures should be used frequently to reduce postoperative bile leaks. Hepatic division is challenged by displaced hepatic vessels and bile ducts, as well as large intrahepatic collateral veins often traversing the parenchyma. Hemorrhage can occur from small veins or regional venous collaterals, which tend to retract into cysts and necessitate suture ligation. Although clinically attractive, the use of staplers to divide the parenchyma has been disappointing due to thickness of the convergent cysts or interface. Simple suture ligatures have proved most reliable. Partial hepatectomy demands preservation of both the portal and hepatic venous systems of the remnant, which can be challenging due to cyst displacement of normal anatomy. All cysts near the major hepatic veins and the IVC should be fenestrated widely to optimize postoperative patency. Specifically, at least half the circumference of the IVC should be exposed and freed of cysts during major hepatectomies. After resection, fenestration and unroofing of cysts in the remnant liver further reduces liver volume. We recommend perihepatic drain placement to address intra-abdominal fluid accumulation and control potential biliary leakage. Although postoperative percutaneous drainage can be performed, it can be challenging due to the irregular liver contour with multiple pockets created by unroofed cysts.
Our study showed that liver volume can be expectedly reduced by more than 50% with sustained improvement in performance and health status. Importantly, however, hepatic resection in patients with PLD is associated with a greater complication rate, longer operative time, and greater blood loss than partial hepatectomy in patients with noncystic, noncirrhotic livers. In our institution, partial hepatectomy for PLD resulted in a 2.3 times greater perioperative morbidity, 1.4 times longer operative time, and 2.3 times greater estimated blood loss when compared with partial hepatectomy for other indications.12
These findings are consistent with other reports that cite a perioperative morbidity of approximately 52% (from 25 pooled patients in 3 representative studies).13–15
The main reason for this observation is the technical difficulty of this operation with distortion of normal anatomy resulting in a greater chance of inadvertent injury of blood vessels and bile ducts; resulting in greater blood loss and a higher incidence of bile leaks. Additionally, transient ascites with prolonged drainage is frequently encountered and can be difficult to manage. The cause of the ascites is likely multifactorial and includes persistent cyst secretion, partial hepatic vein or IVC obstruction, lymphatic leakage, renal dysfunction, and malnutrition. Blood transfusion requirement and, to a lesser extent, reoperation rate decreased throughout the study period presumably due to increased experience. Preoperative blood donation is currently recommended routinely to reduce the need for allogenic transfusion. Moreover, given the lack of underlying liver dysfunction, inflow vascular occlusion during liver tran-section is currently being employed to further reduce transfusion need. Avoidance of blood transfusion when possible is preferred to minimize sensitization of the patient for future need of renal transplantation. However, despite the high risk of this operation, long-term improvement of performance and health status can be achieved in the majority of patients despite of recurrence of frequently minor symptoms.
Cyst fenestration alone should be reserved for patients with less severe disease from a few, superficial, dominant hepatic cysts.16,17
In some patients, percutaneous cyst aspiration can establish causality between symptoms and a particular cyst. However, independent of improvement in symptoms from aspiration, cyst fluid reaccumulation is inevitable.1
Regardless of open or laparoscopic approach, cyst fenestration with unroofing of the cyst wall and coagulative ablation of the cyst epithelium optimizes outcome. Symptom relief has been reported in approximately 53% (from 39 pooled patients in 3 representative studies)18–20
in selected patients compared with 33% (n = 10) in the current study; with an operative morbidity of approximately 44%18–20
compared with 0% in this study.
Liver transplantation may be indicated in highly symptomatic patients with PLD who are not candidates for partial hepatectomy. In rare patients with hepatic insufficiency mostly due to PLD-unrelated pathology, liver transplantation may also be indicated by the standard criteria used in patients with chronic liver disease. Despite marked hepatomegaly, the volume of the functional liver parenchyma is usually normal and hepatocellular function is preserved.21
Since PLD patients have essentially normal liver function, calculated MELD scores are low which makes organ allocation more difficult22
; though, options for appeal through regional review boards are possible. Due to a disadvantage in graft allocation, caval sparing hepatectomy and subsequent living donor liver transplantation might provide a potential alternative for highly selected patients.22
Prior studies showed that 5-year survival after deceased donor liver or combined liver-kidney transplantation is around 80% with good quality of life.23,24
These findings are consistent with our experience. Importantly, survival did not significantly differ between patients undergoing resection and liver transplantation. Liver transplantation as a rescue procedure after partial hepatectomy is uncommon. Our study showed that only 7 of the 124 patients (6%) treated with hepatic resection required salvage liver transplantation due to hepatic failure developed immediately postoperative (n = 2) or during follow-up (n = 2) or due to uncontrollable symptoms during follow-up (n = 3). To date, no clinical trials have been reported comparing outcomes after liver transplantation and hepatic resection with cyst fenestration in patients with PLD and highly symptomatic hepatomegaly. Renal transplantation can be performed synchronous with liver transplantation; however, the decision for renal transplantation should be made independent of the liver disease.
In conclusion, partial hepatectomy with cyst fenestration, cyst fenestration alone, and liver transplantation each play a role in the management of patients with PLD. Cyst fenestration alone can be performed safely, but only provides durable treatment in highly selected patients. Similarly, liver transplantation in light of allocation issues should also be limited to selected patients. Hepatic resection with cyst fenestration currently has the broadest applicability for patients with massive hepatomegaly and highly symptomatic PLD. Although associated with significant morbidity and indolent disease progression, the degree of symptomatic relief and consequential improvement in performance status and overall health warrant its use. Selection of type of treatment should be determined by the patients’ individual hepatic anatomy, hepatic reserve, severity of symptoms, and health status in accordance with our suggested PLD classification.