Intermittent Pedicle Clamping Research Articles

Evaluation of Predictive Values of an Automatic Device Measuring Oximetry in Free Flaps

Summary:Free-flap monitoring is challenging to perform in some centers. It requires the availability of trained health care personnel for 24 hours a day and seven days a week. Many methods had been proposed for flap monitoring, and none of them are superior to clinical evaluation. This study aimed to present a murine model to evaluate the accuracy (sensitivity, specificity, and the positive or negative predictive values) of a device. Wistar rats weighing 240–490 g were included for intervention and data collection. A murine model of left inferior epigastric vessel flaps was implemented. Intermittent pedicle clamping was performed to calculate the accuracy of the device that detects flow obstruction. The general variables studied were age, weight, and gender. The sensitivity, specificity, and negative or predictive values were calculated. The results showed a sensitivity of 97%, a specificity of 95% with a positive predictive value of 95%, and negative predictive value of 97%. The sensitivity and specificity showed excellent results within the range of clinical security. We require more data to analyze the multiparameter monitoring to see if it is feasible and cost-effective.

A Conceptual Technique for Laparoscopic Right Hepatectomy Based on Facts and Oncologic Principles: The Caudal Approach.

To evaluate a new conceptual technique of laparoscopic right hepatectomy. Despite significant improvements in surgical care in the last decades, morbidity is still high after major hepatectomy. Blood loss and transfusions are known to significantly increase the risk of postoperative complications and cancer recurrence after liver resection. A laparoscopic approach may improve perioperative outcomes in these cases, but data in literature are limited and the surgical technique is not yet standardized. A new conceptual technique of right hepatectomy was designed using evidence-based facts and oncologic rules: laparoscopy with pneumoperitoneum, low central venous pressure, intermittent pedicle clamping, anterior approach without mobilization, and parenchymal section with ultrasonic dissector. Thirty patients were prospectively enrolled between October 2011 and September 2013. Primary endpoint was intraoperative blood loss. Eighty percent of patients underwent surgery for malignant disease and cirrhosis was present in 11 patients. Benign lesions accounted for 13% of indications, whereas living liver donation was performed in 2 cases. Median blood loss was 100 mL (50-700) and transfusion rate was 7%. Five patients (16.6%) required conversion to laparotomy, including 2 using hybrid technique. The median operative time was 360 minutes (210-510). R0 resection rate was 87% (21/24). Postoperative morbidity rate was 23% (7/30) with 8 complications including 6 Clavien III-IV. No respiratory complication occurred. The median hospital stay was 8 days. No patient died. This study showed that several evidence-based facts could be combined to define a new conceptual technique of laparoscopic right hepatectomy allowing for low blood loss and morbidity.

Extracorporeal Pringle for laparoscopic liver resection.

A primary concern during laparoscopic liver resection (lapLR) is hemorrhage during parenchymal transection. Intermittent pedicle clamping is an effective method to minimize blood loss during open liver surgery; however, inflow occlusion techniques are challenging to reproduce during laparoscopy. The purpose of this study is to describe the safety and efficacy of a facile method for Pringle maneuver during lapLR. 154 patients who underwent lapLR from 2007 to 2013 were retrospectively reviewed. For Pringle, the hepatoduodenal ligament is encircled with an umbilical tape which is externalized through a flexible Rumel tourniquet running alongside a port used for the operation. The internal end of the catheter is close to the pedicle and the external end is extracorporeal, allowing for easy external occlusion. Patients who underwent Pringle Maneuver (PM, n = 88) were compared to patients who had "No Occlusion" (NO, n = 66) with respect to patient characteristics, operative outcomes, changes in postoperative liver function, and complications. Annual placement of the tourniquet and vascular occlusion increased from 35.7 to 82.8 % (p = 0.004) and 21.4 to 62.1 % (p = 0.02), respectively. Median occlusion time was 24 min (IQR 15-34.3, min 5, max 70). Peak transaminase levels were comparable between groups (AST 298 ± 32 vs 405 ± 47 U/L, p = 0.15; ALT 272 ± 27 vs 372 ± 34 U/L, p = 0.14, NO and PM, respectively). Postoperative transaminase and bilirubin levels for both groups were not significantly different with similar recovery to baseline. Subgroup analysis of cirrhotic patients who underwent Pringle demonstrated similar transaminase profiles compared to non-cirrhotic patients. There were two conversions (1.3 %) and postoperative 30-day mortality was 0.65 %. Extracorporeal tourniquet placement in lapLR is a quick and safe method of gaining control for inflow occlusion. Routine adoption of laparoscopic Pringle maneuver facilitates low conversion rates without liver injury.

Non-cirrhotic liver tolerance to intermittent inflow occlusion during laparoscopic liver resection

While inflow occlusion techniques are accepted methods to reduce bleeding during open liver surgery, their use in laparoscopic liver resections are limited by possible effects of pneumoperitoneum on ischemia-reperfusion liver damage. This retrospective study was designed to investigate the impact of intermittent pedicle clamping (IPC) on patients with normal liver undergoing minor laparoscopic liver resections. Three matched groups of patients were retrospectively selected from our in-house database: 11 patients who underwent robot-assisted liver resection with IPC, and 16 and 11 patients who underwent robot-assisted liver resection without IPC and open liver resection with IPC, respectively. The primary end point was to assess differences in postoperative serum alanine, aspartate aminotransferase (ALT and AST) and bilirubin levels. The curves of serum AST, ALT and bilirubin levels in a span of time of five postoperative days were not significantly different between the three groups. IPC has no relevant effects on ischemia-reperfusion liver damage even in the presence of pneumoperitoneum.

Giant focal nodular hyperplasia determining Budd–Chiari syndrome: an operative challenge requiring 210 min of liver ischemia

Focal nodular hyperplasia (FNH) is a relatively common benign liver tumor with rare indications to surgery. Early after pregnancy, a 35-year-old woman developed right upper quadrant abdominal pain with fever. A large abdominal mass was palpable. Abdominal CT scan showed a 18-cm FNH substituting all liver segments but S6 and S7, compressing middle and left hepatic vein near their origin, displacing and compressing right hepatic vein, with ascites. Surgery consisted of a left hepatectomy extended to S5-S8 and S1. Main technical challenge was the preservation of the right hepatic vein. Intermittent pedicle clamping was performed, associated with hepatic vascular exclusion with preservation of caval flow; total duration of ischemia was 210 min. The postoperative course was uneventful, except for a transient fall in prothrombin time, and the formation of a sub-diaphragmatic serous collection, which was percutaneously drained. The patient is well 25 months after the operation. To our knowledge, this is the second reported case requiring surgery for a FNH causing a Budd-Chiari syndrome. In these peculiar cases a cumbersome operation may be required, maximizing all precautions to perform a risk-free procedure.

Effect of intermittent hepatic pedicle clamping on free radical generation in the rat liver

Background: Intermittent hepatic pedicle clamping is thought to cause less hepatic reperfusion injury compared with continuous clamping. The mechanisms underlying this difference are unknown. We examined the relationship between intermittent ischemia/reperfusion and the production of free radicals using electron spin resonance spectrometry. Methods: Alpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone was administered to rats as a spin trap agent. Continuous clamping (15, 30, or 60 minutes) or intermittent clamping (four cycles of 15-minute ischemia and 5 or 15 minutes of reperfusion) of hepatic pedicle was carried out. After reperfusion, free radical production in the liver was measured by an electron spin resonance spectrometer, and the level of hepatic injury was evaluated by measuring liver enzyme. Results: Longer periods of ischemia increased free radical production after reperfusion. There was no significant increase in free radical production or liver enzymes when the duration of ischemia was 15 minutes. Free radical production and liver damage were significantly less severe in intermittent pedicle clamping than in continuous clamping for 60 minutes, especially when the duration of the reperfusion between four cycles of ischemia was 15 minutes. Conclusions: These results indicate that intermittent pedicle clamping lessens free radical production when compared with continuous clamping, although many free radicals are produced. (Surgery 1998;124:49-56.)

Effect of intermittent hepatic pedicle clamping on free radical generation in the rat liver

Background: Intermittent hepatic pedicle clamping is thought to cause less hepatic reperfusion injury compared with continuous clamping. The mechanisms underlying this difference are unknown. We examined the relationship between intermittent ischemia/reperfusion and the production of free radicals using electron spin resonance spectrometry. Methods: Alpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone was administered to rats as a spin trap agent. Continuous clamping (15, 30, or 60 minutes) or intermittent clamping (four cycles of 15-minute ischemia and 5 or 15 minutes of reperfusion) of hepatic pedicle was carried out. After reperfusion, free radical production in the liver was measured by an electron spin resonance spectrometer, and the level of hepatic injury was evaluated by measuring liver enzyme. Results: Longer periods of ischemia increased free radical production after reperfusion. There was no significant increase in free radical production or liver enzymes when the duration of ischemia was 15 minutes. Free radical production and liver damage were significantly less severe in intermittent pedicle clamping than in continuous clamping for 60 minutes, especially when the duration of the reperfusion between four cycles of ischemia was 15 minutes. Conclusions: These results indicate that intermittent pedicle clamping lessens free radical production when compared with continuous clamping, although many free radicals are produced. (Surgery 1998;124:49-56.)

Optimal cycles of hepatic ischemia and reperfusion for intermittent pedicle clamping during liver surgery.

To evaluate the intermittent clamping of hepatic vessels during liver surgery and to determine the optimal duration of ischemia and reperfusion. One hundred nine adult male Sprague-Dawley rats. Partial (70%) ischemia of the rat liver was induced by clamping of the left pedicle. To assess the influence of a single period of ischemia, the rats were divided into three groups for 15, 20, or 30 minutes of ischemia. To evaluate the influence of reperfusion duration, reperfusion following 15-minute ischemia was repeated 10 times in three groups for 5, 10, or 15 minutes of reperfusion duration. Hepatic tissue blood flow (HTBF) and hepatic beta-adenosine triphosphate (beta-ATP) levels were measured serially, and histopathological specimens were studied following single episodes of ischemia. In the reperfusion experiments, hepatic enzyme levels, survival rates, HTBF, beta-ATP, and histopathological findings were analyzed. When the single period of ischemia was 15 minutes, HTBF and beta-ATP levels recovered after 1 hour of reperfusion. However, both HTBF and beta-ATP levels did not return to preischemic levels when the duration of the ischemia was 20 or 30 minutes. Levels of beta-ATP and HTBF were higher, with improvement in both the histopathological findings and the survival rate, when the duration of the repeated reperfusion periods was 15 minutes, compared with 5 or 10 minutes. The maximum period of ischemia without irreversible damage was 15 minutes in rat liver. The damage was less severe when the duration of the repeated reperfusion periods was 15 minutes rather than 5 or 10 minutes.

Advantages and disadvantages of intermittent pedicle clamping in renal preserving surgery: F. Truss. Brit. J. Urol. 43:35–38 (February), 1971

Advantages and disadvantages of intermittent pedicle clamping in renal preserving surgery: F. Truss. Brit. J. Urol. 43:35–38 (February), 1971