Germano De Cosmo

Pedicle clamping with ischemic preconditioning in liver resection

Hepatic pedicle clamping (HPC) is widely used to control intraoperative bleeding during hepatectomy; intermittent HPC is better tolerated but is associated with blood loss during each period of reperfusion. Recently, it has been shown that ischemic preconditioning (IP) reduces the ischemia‐reperfusion damage for up to 30 minutes of continuous clamping in healthy liver. We evaluated the safety of IP for more prolonged periods of continuous clamping in 42 consecutive patients with healthy liver submitted to hepatectomy. IP was used in 21 patients (group A); mean ± SD of liver ischemia was 54 ± 19 minutes (range, 27‐110; in 7 cases >60 minutes). In the other 21 patients, continuous clamping alone was used (Group B); liver ischemia lasted 36 ± 14minutes (range, 13‐70; in 2 cases >60 minutes). Two patients in Group A (9.5%) and 3 in Group B (14.2%) received blood transfusions. In spite of the longer duration of ischemia (P = .001), patients with IP had lower aspartate aminotransferase (AST; P = .03) and alanine aminotransferase (ALT; P = not significant) at postoperative day 1, with a similar trend at postoperative day 3. This was reconfirmed by multiple regression analysis, which showed that although postoperative transaminases increased with increasing duration of ischemia and of the operation in both groups, the increases were significantly smaller (P < .001) with the use of preconditioning. In conclusion, the present study confirms that IP is safe and effective for liver resection in healthy liver and is also better tolerated than continuous clamping alone for prolonged periods of ischemia. This technique should be preferred to continuous clamping alone in healthy liver. Additional studies are needed to assess the role of IP in cirrhotic liver and to compare IP with intermittent clamping. (Liver Transpl 2004;10:S53–S57.)

Liver resections with or without pedicle clamping

BACKGROUND Decreasing operative bleeding during liver resection, and thus extent of transfusions, has become a main criterion to evaluate operative results of hepatectomies. Hepatic pedicle clamping (HPC) is widely used for this purpose. The aim of the study was to evaluate safety, efficacy, technique, and contraindications of HPC during liver resections, comparing results of resections performed with or without HPC. METHODS Data from 245 liver resections were analyzed. In all, 125 resections were performed with HPC (group A), continuous in 100 cases and intermittent in 25 cases. The average duration of ischemia in group A was 39 +/- 20 minutes (range 7 to 107). In 20 cases (16%) ischemia was prolonged for 60 minutes or more. A total of 120 resections were performed without HPC (group B). Major resections were 53.6% in group A (67 cases) and 38.3% in group B (46 cases). Cirrhosis was present in 36 cases, 19 in group A and 17 in group B. RESULTS Operative mortality was nil. Postoperative mortality was 2.9%, morbidity 22.4%. Percentage of transfused cases (34.4% versus 60.0%; P <0.001) and number of blood units per transfused case (2 +/- 1 versus 4 +/- 3; P <0.001) were lower in group A versus group B. Similar figures were found by considering only major resections. Postoperative blood chemistries did not show important differences between the two groups, and postoperative alterations were related more to extent and complexity of the operation than to length of HPC. CONCLUSIONS HPC during liver resection is a safe and effective technique. This is demonstrated in a context where HPC is used continuously in most cases, intermittently in cases with impaired liver function and for more prolonged ischemia, and avoided in cases with limited bleeding, jaundice, and simultaneous bowel anastomoses.

Hepatic resections in normothermic ischemia

BACKGROUND Reduction of operative blood transfusions is a primary goal in resective surgery of the liver. Temporary vascular inflow occlusion is an effective method to decrease hemorrhage during hepatic resection. This study was performed to assess the impact of normothermic ischemia on intraoperative bleeding and outcome after hepatic resection. METHODS Sixty-one hepatic resections were performed by using pedicle clamping alone or associated with total vascular exclusion of the liver. The mean duration of normothermic ischemia was 40 +/- 18 minutes (range, 7 to 98 minutes). Major resections were performed in 32 cases (52.5%). RESULTS Operative mortality was nil. Major complications occurred in 11.5% of cases. Twenty-five patients (41%) received intraoperative blood transfusions; mean +/- SD of transfused blood units was 2.4 +/- 1.3. Twelve major resections (37.5%) did not require any transfusion. Postoperative changes in liver function test results were moderate and transient. CONCLUSIONS The results of this study confirm the benefit of vascular occlusion techniques in reducing intraoperative bleeding and postoperative complications. The routine use of these techniques during hepatic resections, if applied properly and with the necessary precautions, is not associated with severe adverse effects on liver function.

Extraparenchymal Control of Hepatic Veins During Mesohepatectomy

BACKGROUND Bleeding is the most relevant operative risk during mesohepatectomy because of the wideness of the resection surfaces and the exposure of main intrahepatic vascular structures. Preliminary extraparenchymal exposure of the main hepatic veins, with the possibility of clamping them in association with the Pringle maneuver, and the maintenance of a low central venous pressure during mesohepatectomy, can contribute to substantially reducing operative bleeding. STUDY DESIGN We report the results obtained in 18 mesohepatectomies, performed for liver metastases (13 patients) and for hepatocellular carcinoma (5 patients). Liver resection was performed without preliminary exposure of the main hepatic veins in nine patients (group A) and with preliminary looping of the main hepatic veins in nine patients (group B), without complications related to the maneuver. RESULTS Intermittent pedicle clamping was used in all patients; in six patients in group B (66.7%), clamping of the main hepatic veins was also performed (mean duration, 37 minutes; range 16 to 68 minutes). Intraoperative blood transfusions were needed in 5 patients (5 of 18, 27.8%): 4 belonged to group A (44.4%) and 1 to group B (11.1%). Mortality was nil and morbidity was 33.3%, involving four patients in group A and two in group B (none related to the exposure, looping, and clamping of the main hepatic veins). CONCLUSIONS Preliminary control of the main hepatic veins is a safe maneuver. During mesohepatectomy, clamping of these veins, associated with pedicle clamping, is effective in reducing operative bleeding. In our patients, this resulted in a low blood transfusion rate, similar to that of classic major hepatectomies, despite the higher complexity of mesohepatectomy.

Dreams recall and auditory evoked potentials during propofol anaesthesia

It is unclear whether shorter wave latencies of middle-latency-auditory-evoked-potentials may be associated to cognitive function other than nondeclarative memory. We investigated the presence of declarative, nondeclarative and dreaming memory in propofol-anaesthetized patients and any relationship to intraoperatively registered middle-latency-auditory-evoked-potentials. An audiotape containing one of two stories was presented to patients during anaesthesia. Patients were interviewed on dream recall immediately upon emergence from anaesthesia. Declarative and nondeclarative memories for intraoperative listening were assessed 24 h after awakening without pointing out positive findings. Six patients who reported dream recall showed an intraoperative Pa latency less than that of patients who were unable to remember any dreams (P<0.001). A high responsiveness degree of primary cortex was associated to dream recall formation during anaesthesia.

Effect of remifentanil and fentanyl on postoperative cognitive function and cytokines level in elderly patients undergoing major abdominal surgery.

PURPOSE Postoperative cognitive dysfunction is a frequent complication occurring in geriatric patients. Type of anesthesia and the patients inflammatory response may contribute to postoperative cognitive dysfunction (POCD). In this prospective randomized double-blinded controlled study we hypothesized that intraoperative remifentanil may reduce immediate and early POCD compared to fentanyl and evaluated if there is a correlation between cognitive status and postoperative inflammatory cytokines level. METHODS Six hundred twenty-two patients older than 60 years undergoing major abdominal surgery were randomly assigned to two groups and treated with different opioids during surgery: continuous infusion of remifentanil or fentanyl boluses. Twenty-five patients per group were randomly selected for the quantitative determination of serum interleukin (IL)-1β, IL-6, and IL-10 to return to the ward and to the seventh postoperative day. RESULTS Cognitive status and its correlation with cytokines levels were assessed. The groups were comparable regarding to POCD incidence; however, IL-6 levels were lower the seventh day after surgery for remifentanil group (P= .04). No correlation was found between POCD and cytokine levels. CONCLUSIONS The use of remifentanil does not reduce POCD.

Assessment of risk factors for pancreatic resection for cancer.

Abstract. A series of 101 consecutive patients undergoing pancreatic resection for cancer was retrospectively analyzed to define factors that may affect the immediate postoperative outcome. Overall morbidity and mortality were 28.7% and 10.9%, respectively, although these figures were greatly reduced during the last years; the complication rate dropped from 55.6% (1981–1987) to 20.0% (1993–1995) and the mortality from 16.7% to 6.7%. At univariate statistical analysis the patient characteristics (sex, age, American Society of Anesthesiologists [ASA] class, nutritional status, jaundice), tumor characteristics (site, size, TNM stage, and grading), and type of surgery were found not to affect postoperative morbidity and mortality. In contrast, a significantly lower rate of complications was observed in patients not undergoing gastric resection, in those who received 3 units or less of blood intraoperatively, and in subjects operated more recently (after 1990). At multivariate analysis the period when the operation was performed was the only independent variable that affected the immediate postoperative outcome. Among the examined factors, only the experience acquired over time regarding the intra- and perioperative treatment of these patients seems able to lower the rate of postoperative complications.

No Difference in Early Post Operative Cognitive Dysfunction after Abdominal Surgery with Sevoflurane or Propofol Based General Anesthesia

Background: There is an increasing need to investigate the influence of anesthetics on post-operative cognitive dysfunction (POCD), probably resulting from concurring perioperative stress factors. This study aimed to seek a difference in early POCD after general anesthesia with either propofol or sevoflurane as maintenance agent in patients undergoing abdominal surgery. Methods: Patients older than 60, undergoing general anesthesia for laparotomic abdominal surgery with Sevoflurane/air or Propofol Target Controlled Infusion were included in this observational study. Working and long term memory, attentive capacity and correct reading velocity were evaluated before and 1 week after surgery. POCD was detected from the difference between postoperative and baseline performances, subtracting the learning effect observed in a control group. Results: Of 92 patients included, 25 received propofol and 67 sevoflurane. Overall POCD incidence was 14.14%. POCD was 12.00% in propofol group and 14.93% in sevoflurane group (P = 0.72). There was no significant association between age, sex, duration of surgery or anesthesia and POCD occurrence (P > 0.05). Lower education level (OR = 3.74; 95% CI: 0.78 – 18.04; P > 0.05) and overall pain as referred by patients at 7th day (OR = 1.33; 95% CI: 1.02 – 1.75; P = 0.029) had a high odd of POCD. Conclusion: Our results indicate no preference between sevoflurane or propofol in order to obtain a better early neurocognitive outcome. Pain was associated to POCD generation. In order to verify or exclude anesthetic toxicity, ongoing prospective studies in humans including dosage of neuronal death markers could be useful. *Corresponding author: Alessio Valente, Piazza Monte Torrone 13, 00141 Roma, Italy; Tel: +39 333 2018531; E-mail: neurobios@yahoo.com

Postoperative Analgesia in Thoracic Surgery: A Comparison between Continuous Paravertebral Nerve Block and Continuous Incisional Infusion with OnQ Pain Relief System

Objectives: Thoracotomy is one of the most painful surgical stimuli and inadequate management of postthoracotomy pain is often associated with pulmonary and cardiac complications. The aim of this prospective, randomized, double-blinded study was to compare continuous paravertebral block versus continuous incisional infusion with OnQ Pain Relief System. Methods: Forty eight patients, undergoing thoracotomy for elective lobectomy, were randomized to receive a continuous paravertebral infusion of bupivacaine 0.25% through an elastomeric pump which delivers 0.1 mL/Kg/h (group A) or a continuous incisional infusion of bupivacaine 0.25% at an infusion rate of 4 mL/h with OnQ Pain Relief System (group B). Both infusions were started before wound closure, and continued for 48 postoperative hours. General anaesthesia was standardized. In the recovery room, patients were provided with intravenous morphine patient-controlled analgesia (PCA). Visual analogue scale at rest (VASr) and when coughing (VASi), rescue patientcontrolled analgesia morphine consumption, hemodynamic, time to ambulation and side-effects were evaluated within 48 h. Results: The two groups were comparable regarding to patients’ number and characteristics, type of surgery, time to ambulation and side-effects; postoperative hemodynamic profile was stable in all the patients. Absolute pain scores were low in both groups; patients in group A reported significant lower VASr and VASi values during the postoperative 48 hours compared with group B (p<0.001). Total morphine consumption and PCA requests number were significantly lower in group A than in group B (p= 0.05 and p< 0.01). Conclusions: Continuous incisional infusion of local anesthetic is not as effective as paravertebral analgesia after thoracotomy.