Liver surgery progress in the last 50 years has been groundbreaking. Currently, liver resection has evolved from a high-risk procedure that is justified only in emergencies, to a safe, elective procedure with very low mortality, leading to broad application in a variety of indications [1].

Parenchymal-sparing hepatectomy is a well-established strategy to prevent postoperative liver failure, which allows successful repeat resections [2]. The functional preservation of the remnant liver requires adequate arterial and portal inflow, hepatic venous outflow, and biliary drainage. The lack of one or more of these elements leads to different degrees of focal liver dysfunction.

The right hepatic vein (RHV) drains variable portions of the right anterior (segments 5 and 8) and posterior sections (segments 6 and 7). When a lesion in segments 7 and/or 8 involves the RHV circumferentially, right hepatectomy is usually performed, because RHV resection would compromise the remaining right hemiliver outflow. If a sizable inferior RHV exists, segments 7 and 8 may be resected along with the RHV, without compromising the outflow from segments 5 and 6 [3,4]. However, not all patients have a sizable inferior RHV; therefore, patients undergoing RHV resection frequently need venous outflow reconstruction. Patients with benign disease have an exceedingly low likelihood of requiring repeated resection; and in this setting, RHV reconstruction may not be needed. Herein, we report a case of resection of liver segments 4, 7, and 8, including the right and middle hepatic veins resection without RHV reconstruction.

The study was approved by the ethical committee of the Navy Medical Center (no. 006/2024). Written informed consent was obtained from the patient.

A 52-year-old female was referred to us after a percutaneous pigtail catheter was placed in a large, symptomatic, simple cyst, reportedly containing 2,000 cc of fluid. She has both familial and personal history of autosomal-dominant polycystic kidney disease, currently suffering from chronic kidney disease stage 4 (glomerular filtration 18 mL/min/1.73 m²). It was explained to the patient that the percutaneous catheter would have continuous drainage, as the walls of the cyst were viable, and it was too large to attempt ablation. Her left lateral section, as well as segments 5 and 6, contained only small cysts and large portions of viable parenchyma, while segments 4, 7, and 8 had multiple cysts of variable sizes, with very little liver parenchyma (Fig. 1). We offered liver resection and deceased donor kidney transplant protocol to the patient, as she declined living donor kidney transplantation for personal reasons. An extended right liver resection would resect large portions of viable parenchyma in segments 5 and 6, while leaving behind a borderline future liver remnant (26.7% considering total liver volume, 35.8% considering parenchymal volume after digitally subtracting the cysts; Fig. 1D); therefore, we decided to resect segments 4, 7, and 8, including the right and middle hepatic veins, which were located between the walls of large cysts, and could not be safely dissected to perform outflow reconstruction of segments 5 and 6.

Fig 1. Preoperative unenhanced abdominal computed tomography. Contrast was injected into the drained cyst in a previous study. (A, B) Axial views of segments 7 and 8; (C) large cyst in a small segment 4 with viable parenchyma in segments 5 and 6. (D) Digital reconstruction showing parenchyma in gray, liver cysts in orange, drain in white, and large, partially drained central cyst in pink.

We performed an upper midline incision with right transverse extension, identifying a large liver with multiple cysts of various sizes (Fig. 2). The catheter was divided outside the liver, completely mobilizing both hemilivers. Intraoperative ultrasound failed to demonstrate large right inferior hepatic veins. The RHV was dissected at the point it joined the vena cava and divided with a stapler. The cystic duct and artery were dissected and divided. The gallbladder was freed from segment 5 and resected along with the specimen. The left intersectoral line was divided with a combination of ultrasonic aspiration, a vessel sealing device, and stapler, with vascular loads. The middle hepatic vein was divided with a stapler. Segments 4 and 5 were divided until the upper border of the hilar plate was identified, then the line of transection was shifted to the right while performing intermittent Pringle maneuver, dividing segments 7 and 8 pedicles with a stapler (Fig. 3). The remaining cyst walls in the parenchymal transection walls were cauterized with monopolar cautery, and the superficial cysts of remaining segments 1, 2, 3, 5, and 6 were fenestrated, and their walls were cauterized in the same fashion. Two surgical drains were placed, one behind the remaining right segments, and the other over the transection surface. Estimated blood loss was 600 cc, and the patient received no blood products; surgical time was 4 hours.

Fig 2. Surgical view of the liver before resection.

Fig 3. Surgical view of the liver after resection. (A) After parenchymal transection; (B) after specimen removal.

The patient made an uneventful recovery, and there were no clinically significant changes in her liver function tests (Table 1). She was discharged on postoperative day 5, and the drains were removed on day 10. Her renal function was preserved (Table 1). Pathology examination revealed polycystic liver disease, liver fibrosis around the cysts, and multiple biliary hamartomas. After recovering from surgery, the patient declined deceased donor kidney transplant listing. Three months after the operation, her renal function was preserved, and an unenhanced abdominal computed tomography showed partial atrophy of segments 5 and 6, and hypertrophy of segments 2 and 3 (Fig. 4). Two and one half years after the operation, she is asymptomatic, on stable hemodialysis, with residual urinary volume of 2 liters. A new computed tomography shows resolution of the right pleural effusion and a total liver volume of 1,548 cc, with cyst volume of 155 cc, leaving 1,393 cc of parenchymal liver volume (Fig. 4D), which is similar to her expected standard liver volume of 1,422 cc [5]. She continues to refuse kidney transplantation.

Table 1 . Laboratory tests before and after liver resection

Test	PreOp	POD 0	POD 1	POD 3	POD 5	POM 30
Creatinine (mg/dL)	2.82	2.79	3.17	3.57	2.38	5.28
Cystatin C (mg/dL)	2.58	-	-	3.00	-	3.77
FG (mL/min)	18.6	18.9	16.2	14.0	22.8	11.4
AST (UI/L)	38	325	263	104	-	19
ALT (UI/L)	34	112	112	81	-	14
Total bilirubin (mg/dL)	0.36	1.07	0.67	0.32	-	0.47
Hemoglobin (g/dL)	11.1	9.8	10.6	9.7	10.5	13.4
Platelets (×109/L)	248	175	200	209	561	171
INR	1.065	1.518	1.476	1.130	-	1.000

FG, glomerular filtration; AST, aspartate amino transferase; ALT, alanine amino transferase; INR, international normalized ratio; PreOp, before operation day; POD, postoperative day; POM, postoperative month.

Fig 4. Unenhanced abdominal computed tomography 90 days after liver resection. (A) Small, asymptomatic right pleural effusion. (B, C) Partial atrophy of segments 5 and 6 with hypertrophy of the left lateral section. (D) Postoperative digital reconstruction of unenhanced computed tomography two and a half years after the operation, showing parenchyma in gray, and liver cysts in orange.

Liver resection and transplantation are well-established surgical strategies for highly symptomatic patients with polycystic liver disease. Liver resection in these population has a low perioperative mortality (2.7%), and excellent durability of symptom relief and quality of life after long-term follow-up (up to 15 years) [6,7].

Our patient exhibited an excellent postoperative course, leaving the hospital with normal liver function after five days. Based on the estimated future liver remnant of 35.8% after an extended right hepatectomy, it is possible that she could have tolerated that procedure; however, we were concerned about the impact that a smaller future liver remnant would have in a patient with chronic kidney disease and liver fibrosis, opting for a more conservative, albeit more technically-demanding resection, which allowed for the preservation of a significant amount of parenchyma in segments 5 and 6.

Obstruction of the RHV during resection of segments 7 and 8 is widely stated in the literature to lead to venous congestion of segments 5 and 6. The current case demonstrates that venous congestion to segments 5 and 6 had no impact on liver function tests. Possibly, after obstruction of the right and middle hepatic veins, the right portal vein could become an outflow to the right hepatic artery inflow to segments 5 and 6, allowing segments 5 and 6 to maintain partial function without liver congestion or dysfunction in the short term. However, the lack of portal flow could lead to the observed partial atrophy of segments 5 and 6, while increased contralateral portal flow leads to hypertrophy. This is the same phenomenon observed in right portal vein embolization, where the hepatic artery becomes the sole inflow to the right hemiliver, which maintains partial function, while the lack of portal flow to the right hemiliver induces partial atrophy and hypertrophy of the contralateral side [8]. The presence of “growth factors” in the portal blood flow has been widely theorized, and demonstrated by Starzl et al. [9].

It is highly unlikely for our patient to need repeated liver resection. In the case of recurrence of symptoms, she would be a candidate for liver (and kidney) transplantation [10,11]. The eventual functional loss of volume of segments 5 and 6 had no impact on their postoperative liver function. If the indication for liver resection of segments 7 and 8 would be malignant disease, particularly those amenable to repeated resection (colorectal liver metastases, hepatocellular carcinoma, intrahepatic cholangiocarcinoma, among others) [12-14], she would have definitively benefited from hepatic venous reconstruction [15,16]. A possible explanation for the uneventful recovery of the patient is that imaging studies failed to correctly identify a large right inferior hepatic vein; however, in that case, segments 5 and 6 would not have suffered partial atrophy.

In conclusion, RHV reconstruction may be unnecessary in patients undergoing liver resection of segments 7 and 8, with low likelihood of repeated resection. Preservation of segments 5 and 6 may provide enough liver mass to recover until hypertrophy of the contralateral side occurs.

The opinions expressed are under individual responsibility and do not reflect the point of view of the Secretaría de Marina (Dir. 003/2021).

None.

No potential conflict of interest relevant to this article was reported.

Conceptualization: DZV. Data curation: PLL, CUCS. Methodology: PLL, CUCS. Writing - original draft: DZV. Writing - review & editing: All authors.