Synchronous liver resection and cryotherapy for colorectal metastases: survival analysis.

INTRODUCTION: The value of synchronous liver resection and cryotherapy ablation remains controversial for colorectal metastases where complete resection is not possible by conventional liver surgery alone. OBJECTIVE: To review the long-term survival of patients treated using this approach at our institution. METHODS: A review was undertaken of data held in the prospectively collected liver surgery database of all patients who underwent synchronous liver resection and cryotherapy. Survival analysis was performed and data recorded on the total number of metastases at initial surgery and the number of lesions treated by cryoablation. RESULTS: Ninety-three patients with colorectal metastases underwent synchronous liver resection and cryotherapy. Data were available on 86 patients with a median follow-up of 18 months (range 1-83). The median number of metastases at initial surgery was four (range 2-11) and the number of lesions treated by cryotherapy ablation was two (range 1-8). Eighty-four per cent had a hepatic artery catheter inserted at surgery and at least one cycle of post-operative hepatic artery chemotherapy. One-, three- and five-year survival was 85%, 43% and 19% respectively, with a median survival of 33 months (95% confidence interval 19.9-42.1). Site of recurrence was recorded and presented. CONCLUSIONS: Patients with liver metastases that are not amenable to resection alone can achieve worthwhile median survival with synchronous liver resection and cryotherapy ablation.

Ultrasound-guided insertion of subclavian venous access ports.

INTRODUCTION: Central venous cannulation is an integral part of venous access port (portacath) placement for intravenous chemotherapy. NICE guidelines have suggested that CVC should be performed under ultrasound guidance. The technique of ultrasound-guided subclavian cannulation is reviewed and our experience presented. PATIENTS AND METHODS: Retrospective analysis of data on patients undergoing ultrasound-guided portacath placement for the failure rate and the incidence of complications. RESULTS: We were successful in cannulating the subclavian vein in 44 of 55 patients. There was one arterial puncture and no haemothorax or pneumothorax with the technique (complication rate 1.8%). CONCLUSION: An ultrasound-guided approach should be the standard technique for central venous cannulation in portacath placement.

Hepatic portal vein gas as a complication of cryotherapy.

BACKGROUND: Hepatic portal vein gas (HPVG) is a radiological finding normally associated with life-threatening conditions such as mesenteric ischaemia and necrotising enterocolitis in infants. Its presence has previously been associated with a high mortality rate. As a result of more sensitive imaging modalities the spectrum of conditions for which portal vein gas is detected has broadened. We present a patient who developed HPVG as a complication of cryotherapy. The association between portal vein gas and cryotherapy has not previously been described in well over one thousand patients with hepatic cryotherapy reported in the literature.

Characterization of contractile prostanoid receptors on human airway smooth muscle.

In human bronchial rings the thromboxane A2 (TxA2) mimetic, U46619, produced cumulative concentration-related contractions up to a maximum of 141 +/- 23% of the response induced by carbachol or acetylcholine. The geometric mean EC50 value was 3.2 X 10(-8) M (95% confidence interval: 1.2, 8.9 X 10(-8) M) (n = 5). Contractions to U46619 were unaffected by atropine (10(-6) M) or verapamil (10(-5) M), but were competitively antagonized by the TxA2 antagonist GR32191 with a pA2 value of 8.40 +/- 0.41. The maximum contractile response to prostaglandin (PG) F2 alpha was smaller (90 +/- 9%, n = 13) and the potency was less (EC50 = 2 X 10(-6) M) than that of U46619. Contractions to PGF2 alpha were also competitively antagonized by GR32191 with a pA2 value of 8.18 +/- 0.08. Concentration-response curves to PGE2 were biphasic, relaxation at concentrations from 10(-9) to 10(-6) M and contraction from 10(-6) to 3 X 10(-5) M. GR32191 10(-7) M inhibited the contractile portion of the response curve in 8 of 11 tissues. Based on these results we conclude that U46619, PGF2 alpha and PGE2 all contract human airways by stimulation of the TxA2 (TP) receptor.

Inhibition by prostaglandin E2 of neurotransmission in rabbit but not human bronchus--a calcium-related mechanism?

Prostaglandins have been implicated in the development of airway hyperresponsiveness, and this may be mediated via modulation of neurotransmission. We compared the effects of prostaglandin E2 on the contractile response to electrical field stimulation in rabbit and human bronchus. Prostaglandin E2 produced marked inhibition in rabbit bronchus (mean % inhibition 35 +/- 17, P less than 0.05) but was without effect in human bronchus. The inhibition in rabbit bronchus was not the result of a direct effect on muscle tone and the site of action is likely to be pre-synaptic since prostaglandin E2 had only minor effects on exogenous acetylcholine. Since prostaglandins are known to affect calcium mobilization, we compared the dependence of cholinergic stimulation on the calcium voltage dependent channel (VDC) in the two species. Cholinergic stimulation was dependent on the VDC in rabbit but not human bronchus and this may be an explanation for the different effects of prostaglandin E2 in the two species.