Complete Versus Selective Portal Triad Clamping for Minor Liver Resections

To the Editor:

It was with great interest that we read the article by Figueras and colleagues.¹ Congratulations to the authors for the well-designed prospective randomized trial.

In fact, intraoperative bleeding in liver surgery is still a major concern, and morbidity and mortality are clearly correlated with the amount of blood loss.² Vascular clamping during transection of liver parenchyma may reduce bleeding; therefore, the Pringle maneuver has been traditionally applied during hepatectomy to reduce blood loss.^3,4

Since the prospective evaluation of vascular occlusion in hepatectomy by Man et al, the Pringle maneuver has become an option for performing liver resections with intermittent clamping.⁴ The complication rate, hospital mortality rate, and ICG (indocyanine green) retention at 15 minutes on postoperative day 8 were equivalent in the Pringle and the control group. Man et al⁴ included all types of hepatectomies in their study and did not distinguish between major and minor hepatectomies. In addition, ischemic preconditioning as a consequence of intermittent Pringle maneuver provides better intraoperative hemodynamic stability and ischemic tolerance, as illustrated by Chouker et al.⁵ The beneficial effect of “ischemic preconditioning” might be related to down-regulation of cytotoxic effects of polymorphonuclear leukocytes.⁶

However, ischemic damage still remains a major concern, particularly in patients with underlying acute or chronic liver disease with a significant increase in postoperative morbidity and liver dysfunction rates.^7,8 A recent paper by Kukita et al showed that the Pringle maneuver in hepatectomy caused remnant liver injury in a pig model by expression of iNOS, a marker related to ischemia/reperfusion injury.^9,10

The ideal alternative would be to perform liver resection without clamping but with modern equipment that prevents or reduces significant bleeding.

Nowadays, minor liver resections are a routine operative procedure in a high-volume surgical center. With the development of modern tools for transection-coagulation such as “CUSA” and water-irrigated forceps, as we routinely use in our department, a selective and safe approach with identification and isolation of the vascular structures is guaranteed during transection of the liver parenchyma.

We believe, as previously described, that intraoperative ultrasonographic guidance and low venous pressure are effective methods for preventing bleeding with inflow preservation.¹¹

In a recently published prospective study, Scatton et al successfully performed 53 major liver resections without clamping in 96% of patients with an acceptable complication rate and no reoperations. The mean bleeding volume was 250.1 ± 591.7 mL. There were 3 transient liver dysfunctions in patients with underlying chronic liver disease, who underwent extended hepatectomies.¹²

We perform liver resections with a planned portal triad clamping only in emergency situations.

We reviewed 10 consecutive minor liver resections out of 45 liver resections performed in the last 6 months at our center. The 10 analyzed cases of minor noncirrhotic liver resection, including benign and malignant indications, had inclusion criteria similar to those described by the authors. After laparotomy, an intraoperative sonography was performed, and mobilization of the liver lobe/segments was followed by parenchyma dissection. Additionally, the cut surface was continuously coagulated using a water-irrigated forceps.

Mean ZVD was 8 ± 2 mm H₂O at the beginning of liver transection, and on average 2700 ± 1300 mL crystalloids and 600 ± 900 mL colloids were given perioperatively. Mean blood loss was 125 ± 525 mL. None of the patients required a blood transfusion. Three patients required low doses of catecholamines. Overall mean operative time was 4 ± 1.25 hours, and mean hospital stay including preoperative evaluation was 11.2 ± 8 days. No reintervention or transitory or temporary hepatic insufficiency occurred postoperatively. In fact, no patient suffered a postoperative complication.

Obviously, the blood loss described by Figueras et al was quite high at 671 ± 533 mL in the complete clamping group and 735 ± 397 mL in the selective clamping group. At our institution, liver transection using “CUSA” is performed slowly and carefully with selective clip ligation of all vascular structures. Thus, our mean operating time of 4 hours was obviously longer, but this might be the reason for the lower blood loss as compared with Figueras et al.

In conclusion, a review of the current literature shows that performance of a Pringle maneuver in elective hepatectomy is still controversial.

We feel that for minor liver resections clamping of the hilus is not necessary; therefore, additional risky preparations of the vascular structures, especially when selective clamping is performed, can be avoided.

However, a randomized prospective trial comparing minor hepatectomies under intermittent Pringle maneuver or without clamping using modern equipment with minor hepatectomies performed by an experienced team would be appropriate.

Ingmar Königsrainer, MD
Ruth Ladurner, MD
Wolfgang Steurer, MD
Alfred Königsrainer, MD
Department of General Visceral and Transplant Surgery
Tübingen University Hospital
Tübingen, Germany
ikoenigsrainer@web.de or
ingmar.koenigsrainer@med.uni-tuebingen.de