High-frequency jet ventilation shortened the duration of gas embolization during laparoscopic liver resection in a porcine model.

BACKGROUND: Positive pressure mechanical ventilation causes rhythmic changes in thoracic pressure and central blood flow. If entrainment occurs, it could be easier for carbon dioxide to enter through a wounded vein during laparoscopic liver lobe resection (LLR). High-frequency jet ventilation (HFJV) is a ventilating method that does not cause pronounced pressure or blood flow changes. This study aimed to investigate whether HFJV could influence the frequency, severity, or duration of gas embolism (GE) during LLR. METHODS: Twenty-four anaesthetized piglets underwent lobe resection and were randomly assigned to either normal frequency ventilation (NFV) or HFJV (n=12 per group). During resection, a standardized injury to the left hepatic vein was created to increase the risk of GE. Haemodynamic and respiratory variables were monitored. Online blood gas monitoring and transoesophageal echocardiography were used. GE occurrence and severity were graded as 0 (none), 1 (minor), or 2 (major), depending on the echocardiography results. RESULTS: GE duration was shorter in the HFJV group (P=0.008). However, no differences were found between the two groups in the frequency or severity of embolism. Incidence of Grade 2 embolism was less than that found in previous studies and physiological responses to embolism were variable. CONCLUSION: HFJV shortened the mean duration of GE during LLR and was a feasible ventilation method during the procedure. Individual physiological responses to GE were unpredictable.

Elevated PEEP without effect upon gas embolism frequency or severity in experimental laparoscopic liver resection.

BACKGROUND: Carbon dioxide (CO(2)) embolism is a potential complication in laparoscopic liver surgery. Gas embolism (GE) is thought to occur when central venous pressure (CVP) is lower than the intra-abdominal pressure (IAP). This study aimed to investigate whether an increased CVP due to induction of PEEP could influence the frequency and severity of GE during laparoscopic liver resection. METHODS: Twenty anaesthetized piglets underwent laparoscopic left liver lobe resection and were randomly assigned to either 5 or 15 cm H(2)O PEEP (n=10 per group). During resection, a standardized injury to the left hepatic vein [venous cut (VC)] was created to increase the risk of GE. Haemodynamic and respiratory variables were monitored, and online arterial blood gas monitoring and transoesophageal echocardiography (TOE) were used. The occurrence and severity of embolism was graded as 0 (none), 1 (minor), or 2 (major), depending on the TOE results. RESULTS: No differences were found between the two groups regarding the frequency or severity of GE, during either the VC (P=0.65) or the rest of the surgery (P=0.24). GE occurred irrespective of the CVP-IAP gradient. CONCLUSIONS: Mechanisms other than the CVP-IAP gradient seemed during laparoscopic liver surgery to contribute to the formation of CO(2) embolism. This is of clinical importance to the anaesthetists.

High intra-abdominal pressure during experimental laparoscopic liver resection reduces bleeding but increases the risk of gas embolism.

BACKGROUND: Various recommendations exist regarding intra-abdominal pressure (IAP) during laparoscopic liver resection. A high IAP may reduce bleeding but at the same time increase the risk of gas embolism. This study investigated the effects of two different IAPs during laparoscopic left liver lobe resection in piglets. METHODS: Sixteen piglets underwent laparoscopic left liver lobe resection using carbon dioxide pneumoperitoneum of either 8 or 16 mmHg (8 per group). A combination of CUSA System 200™ and LigaSure™ instruments was used for parenchymal division. During resection, a standard injury to the left liver vein was also created to increase the risk of bleeding and/or gas embolism during the operation. Heart rate, cardiac output, and arterial, pulmonary arterial, pulmonary capillary wedge and central venous pressures were measured. Arterial blood gases were monitored continuously. Transoesophageal echocardiography was video recorded to detect and quantify gas embolism within the right cardiac ventricle. The duration of operation and bleeding were noted. RESULTS: High IAP resulted in reduced bleeding (P = 0·016), but gas embolism occurred more frequently (P = 0·001) than with low IAP. Gas embolism disturbed gas exchange, with an increase in arterial pressure of carbon dioxide, and a decrease in arterial partial pressure of oxygen and pH. These effects were sustained for at least 30 min after surgery. CONCLUSION: High IAP reduces the amount of bleeding but increases the risk of gas embolism. Monitoring for gas embolism is therefore indicated if a high IAP is used during laparoscopic liver resection.

Gas embolism during laparoscopic liver resection in a pig model: frequency and severity.

BACKGROUND: Laparoscopic liver surgery is evolving rapidly. Carbon dioxide embolism is a potential complication. The aim of this work was to study the frequency and severity of gas embolism (GE) during laparoscopic liver lobe resection in a pig model and the resulting cardiovascular and respiratory changes. METHODS: Fifteen anaesthetized piglets underwent laparoscopic left liver lobe resection. Haemodynamic and respiratory variables were monitored, including systemic and pulmonary arterial pressures, end-tidal CO2, and pulmonary dead space. Online blood gas monitoring and a transoesophageal echocardiography (TOE) were used. GE was graded semi-quantitatively as grade 0 (none), grade 1 (minor), or grade 2 (major), depending on the TOE results. RESULTS: In 10 of 15 piglets, GE occurred. In total, 33 separate episodes of GE were recorded. All 13 episodes of grade 2 and three of grade 1 were serious enough to cause mainly respiratory, but also haemodynamic effects. Mostly, grade 1 GE caused only minor respiratory or haemodynamic changes. Most variables were affected during grade 2 GE; the most important were Pa(o(2)), Pa(co(2)), end-tidal CO2, Vd/Vt, and mean pulmonary arterial pressure. CONCLUSIONS: GE occurred frequently during laparoscopic liver resection in this experimental study. Approximately half of the embolisms were serious enough to cause respiratory or haemodynamic disturbances or both. Pending further human studies, a combination of several monitoring techniques, with narrow limits for the alarm settings, will ensure correct interpretation of the complex physiological response to GE and reveal it early enough to alert the anaesthetist and the surgeon to the ongoing problem.

The result of liver resection for colorectal metastases in a small volume hospital in western Norway.

AIM: Our aim was to compare liver resection for colorectal metastases in a non-referral, small volume unit with a dedicated staff, with results from larger units. METHODS: Thirty patients (15 men and 15 women) with a median age of 64years (range 29-78) underwent hepatic resection during a 5-year period from 1997 to 2003 in a teaching hospital in western Norway. RESULTS: Sixty-three percent (19/30) of the colorectal tumours were Dukes stage C (n=19) and CEA was increased in seven patients (23%), of which four (13%) had values above 50microg/l. The metastases were synchronous with the colorectal tumours in 11 patients (37%). Non-anatomical (wedge) resections were the dominant type of surgeries and the resection margins were clear in all patients. A 77-year-old man (3%) died of MOF after right hemihepatectomy. Morbidity was encountered in eight other patients (28%). In 22 patients (76%) with recurrent disease, metastases first appeared in the liver in 18 (82%) of these patients. Seven patients (23%) have had resections for recurrences. Mean time to recurrence was 20months (range 3-87). The actuarial 5-year survival rate was 42%. Six patients (20%) are currently disease free. CONCLUSION: Although our unit has treated a small number of patients compared with specialized units elsewhere, the survival rate, as well as morbidity and mortality, were comparable. However, 62% have had recurrent liver disease and this may suggest a role for neoadjuvant or adjuvant chemotherapy in selected cases.

Treatment of pancreatic pseudocysts.

According to the Atlanta classification an acute pseudocyst is a collection of pancreatic juice enclosed by a wall of fibrous or granulation tissue, which arises as a consequence of acute pancreatitis or pancreatic trauma, whereas a chronic pseudocyst is a collection of pancreatic juice enclosed by a wall of fibrous or granulation tissue, which arises as a consequence of chronic pancreatitis and lack an antecedent episode of acute pancreatitis. It is generally agreed that acute and chronic pseudocysts have a different natural history, though many reports do not differentiate between pseudocysts that complicate acute pancreatitis and those that complicate chronic disease. Observation--"conservative treatment"--of a patient with a pseudocyst is preponderantly based on the knowledge that spontaneous resolution can occur. It must, however, be admitted that there is substantial risk of complications or even death; first of all due to bleeding. There are no randomized studies for the management protocols for pancreatic pseudocysts. Therefore, today we have to rely on best clinical practice, but still certain advice may be given. First of all it is important to differentiate acute from chronic pseudocysts for management, but at the same time not miss cystic neoplasias. Conservative treatment should always be considered the first option (pseudocysts should not be treated just because they are there). However, if intervention is needed, a procedure that is well known should always be considered first. The results of percutaneous or endoscopic drainage are probably more dependent on the experience of the interventionist than the choice of procedure and if surgery is needed, an intern anastomosis can hold sutures not until several weeks (if possible 6 weeks).

[Peptic ulcer perforations, University Hospital of Iceland 1989-1995.].

OBJECTIVE: In this audit we looked at patients who came in to the University Hospital of Iceland, diagnosed to have perforated peptic ulcer, with the aim to gain information about the patients and the treatment. MATERIAL AND METHODS: Information was from patients' notes, of 72 patients presenting with perforated peptic ulcer, from 1 January 1989 to 31 December 1995. Mean age of patients was 59 years. Male: female 1:1. RESULTS: Twenty nine persent of the patients had history of previous peptic ulcer. One third of the patients were receiving NSAID at the time of perforation, 54% had gastric perforation and 45% duodenal perforation. Fourty four (64%) did undergo laparotomy and 25 (36%) laparoscopy. Of the 25, 11 operations were converted to laparotomy. Mortality was 13%. Patients, that had laparoscopic treatment, were discharged 2.3 days earlier on average, compared to those undergoing laparotomy. Thirty one (45%) patients had concomitant disease(s). CONCLUSIONS: A large proportion of patients coming to hospital with perforated peptic ulcers are older people, many with serious concomitant diseases. Laparoscopic treatment of perforated ulcers are equal to lapotomy, altough laporoscopic treatment shows a trent towards shortening of postoperative treatment in hospital.