PO2 in the carotid body perfused and/or superfused with cell-free media

We measured with a micro-O2 electrode the tissue PO2 (PtO2) in the cat carotid body (CB) to see whether it was adequately oxygenated when perfused or superfused with artificial, cell-free (c-f) solutions (pH = 7.4; temp = 35-38 degrees C). To obtain a relative measure of O2 consumption (VO2), we also measured the rate of disappearance of O2 following stoppage of the blood flow, and compared these disappearance curves with those during stoppage of the c-f perfusion solutions. In 14 cats normal (blood perfusion) PtO2 values ranged from 10 to 104 mmHG; chi = 72 +/- 4 (SE--as used throughout). During 3 h of c-f perfusion with air-equilibrated Locke's solution, PtO2 ranged from 62 to about 160 mmHg; chi = 133 +/- 4. When perfused with Fay's equilibrated with 98% O2-2% CO2 no PtO2 values in the CB were below 300 mmHg (4 cats). In eight additional cats the CB was cleared of blood then superfused with saline equilibrated with 50% O2 underneath and air-equilibrated saline over. Less than 5% of the PtO2 values found were below 5 mmHg. We conclude that most studies on the artificially perfused or superfused CB cannot be invalidated on the basis that the preparations were hypoxic. O2 disappearance curves taken during blood perfusion were significantly faster than during c-f perfusion indicating a marked reduction in VO2 with c-f perfusion.     

Bovine haemoglobin is more potent than autologous red blood cells in restoring muscular tissue oxygenation after profound isovolaemic haemodilution in dogs

PURPOSE: This study compares the effects of stored red cells, freshly donated blood and ultrapurified polymerized bovine haemoglobin (HBOC) on haemodynamic variables, oxygen transport capacity and muscular tissue oxygenation after acute and almost complete isovolaemic haemodilution in a canine model. METHODS: Following randomization to one of three groups, 24 anaesthetized Foxhounds underwent isovolaemic haemodilution with 6% hetastarch to haematocrit levels of 20%, 15% and 10% before they received isovolaemic stepwise augmentation of 1 g.dl-1 haemoglobin. In Group 1, animals were given autologous stored red cells which they had donated three weeks before. In Group 2, animals received freshly donated blood harvested during haemodilution. In Group 3, animals were infused with HBOC. Skeletal muscle tissue oxygen tension was measured with a polarographic 12 mu needle probe. RESULTS: In all groups, heart rate and cardiac index were increased with decreasing vascular resistance during haemodilution (P < 0.05). Haemodynamic variables showed a reversed trend during transfusion when compared to haemodilution but remained below baseline (P < 0.05). Arterial and venous oxygen content were changed in parallel to changes of haematocrit and haemoglobin concentrations but were lower in Group 3 than in Groups 1 and 2 (P < 0.05) during transfusion. In contrast, the oxygen extraction ratio was higher in Group 3 (59 +/- 8%, P < 0.01) at the end of transfusion than in Group 1 (37 +/- 13%) and 2 (32 +/- 5%). In Group 3, mean tissue oxygen tension increased from 16 +/- 5 mmHg after haemodilution to 56 +/- 11 mmHg after transfusion (P < 0.01) and was higher than in Group 1 (41 +/- 9, P < 0.01) and Group 2 (29 +/- 11, P < 0.01). While in Group 3 an augmentation of 0.7 g.dl-1 haemoglobin resulted in restoring baseline tissue oxygenation, higher doses of 2.7 g.dl-1 and 2.1 g.dl-1 were needed in Groups 1 and 2 to reach this level (P < 0.01). CONCLUSION: The results show a higher oxygenation potential of HBOC than with autologous stored red cells because of a more pronounced oxygen extraction.     

Efficacy of exogenous fibronectin in wound healing in malnourished rats

BACKGROUND/PURPOSE: Fibronectin (FN) plays an important role in fibrin matrix formation during the wound healing process. The authors investigated whether exogenous FN increases the bursting strength (BS) of surgical wounds in malnourished rats. METHODS: Ninety rats were grouped according to three nutritional conditions (n = 30 in each group). All animals underwent a transverse celiotomy after 3 weeks of feeding, and FN (2 mg/body/day) was given postoperatively to 15 rats in each of the three groups. Wound BS was measured on postoperative days (PODs) 3, 5, and 7 after removal of the sutures. RESULTS: BS in normally nourished rats (group N; 142.6+/-23.4 mmHg) was significantly higher than that in protein malnourished rats (group PM, 110.2+/-11.2 mm Hg) and protein/ calorie (Cal)-malnourished rats (group PCM, 76.5+/-10.7 mm Hg) on POD 7 (P<.01). However, BS values for groups PM + FN (147.0+/-21.1 mmHg) and PCM + FN (115.1+/-28.9 mm Hg) were intensified significantly in comparison with groups PM and PCM (P<.01). Plasma FN levels in rats of the three FN nontreated groups were similarly decreased on POD 3 or 5, but returned to the preoperative level on POD 7, whereas those for the other three FN-treated groups increased after POD 3. CONCLUSION: Intravenous administration of FN might strengthen the weakened wounds of malnourished animals.     

Effects of early postoperative 5-fluorouracil and ageing on the healing capacity of experimental intestinal anastomoses

BACKGROUND: Results from a previous study suggested that advanced age does not affect early repair of experimental intestinal anastomoses. The present study aimed to establish whether anastomotic healing is impaired more easily in old animals by immediate postoperative chemotherapy. METHODS: Young adult (2-3 months) and old (27-30 months) rats underwent resection and anastomosis of both ileum and colon. Within each age group, subgroups received intraperitoneal saline or 5-fluorouracil in a dose of 15 or 20 mg per kg per day from the day of operation onwards. After 7 days, anastomotic healing was assessed by wound strength and collagen deposition in the wound area. RESULTS: No differences were found between young and old control groups. The higher dose of fluorouracil induced severe loss of strength with concomitant reduction of wound collagen, which was similar in both age groups (ileum: from 52(13) to 24(8) volume per cent in young animals and from 56(10) to 20(9) volume per cent in old animals; colon: from 58(10) to 37(18) volume per cent in young animals and from 65(5) to 30(17) volume per cent in old animals). The lower dose of fluorouracil induced a significantly greater loss of strength, measured as the bursting pressure, in the old animals (150(49) versus 201(59) mmHg in colon of young rats). CONCLUSION: In this model early anastomotic repair in older animals proceeds normally under optimal conditions, but it is more easily disturbed in the presence of fluorouracil.     

A system to simulate gas exchange in humans to control quality of metabolic measurements

The present experiments were designed to compare the behavior of cerebral blood flow (CBF) during acute moderate and severe hypotensive episodes induced by either ventricular tachycardias (VT) or by hemorrhage. Using the microsphere method CBF was determined in 20 Sprague-Dawley rats during sinus rhythm (Group A), in 28 animals during high-rate VT (Group B) and in 10 animals after hemorrhage (Group C). According to the decrease in blood pressure and with respect to the lower threshold of cerebral autoregulation Group B was divided into 2 subgroups (B1: 80-130 mmHg; B2: 50-80 mmHg) retrospectively. While CBF remained constant in Group B1 (0.98 +/- 0.3 ml g-1 min-1 vs. 1.01 +/- 0.32 in controls, NS), CBF decreased markedly during severely hypotensive VT in Group B2 (0.52 +/- 0.2 ml g-1 min-1, p < 0.001 vs. A; p < 0.05 vs. C) and during hypovolemic hypotension in Group C (0.77 +/- 0.22 ml g-1 min-1 vs. A; NS). Cerebrovascular resistance and autoregulation indices indicated a maintenance of CBF regulation during hypovolemic hypotension and a failure during normovolemic hypotension. These findings indicate that the autoregulatory ability of the brain is substantially more stable during hypovolemic hypotension than during normovolemic hypotension. Therefore, the hemodynamic sequelae of acute hypotensive episodes on CBF depend on the underlying cause of hypotension.     

Delayed onset of malignant hyperthermia induced by isoflurane and desflurane compared with halothane in susceptible swine

BACKGROUND: Desflurane (difluoromethyl 1-fluoro 2,2,2-trifluoroethyl ether) is a new inhalational anesthetic currently under investigation for use in humans. Recently, the authors showed that desflurane is a trigger of malignant hyperthermia (MH) in susceptible swine. To date, there has been no in vivo comparison of the relative ability of inhalational anesthetics to trigger MH. The effects of desflurane, isoflurane, and halothane on six MH-susceptible purebred and six MH-susceptible mixed-bred Pietrain swine were examined. METHODS: The animals were exposed to 1 MAC and 2 MAC (if MH was not triggered after 1 MAC hour) doses of each of the three volatile anesthetics in random sequence at 7-10-day intervals and changes in end-tidal CO2, arterial blood gases, serum lactate, core and muscle temperature, blood pressure, and heart rate were measured. RESULTS: There was a statistical difference between anesthetics in the time required to trigger MH; halothane exposure resulted in the fastest onset of an MH episode (20 +/- 5 min), compared with isoflurane (48 +/- 24 min) and desflurane (65 +/- 28 min), both of which required significantly longer exposures. There was no statistical difference between the MH purebred and mixed-bred swine in the time required to trigger MH (defined as a PaCO2 of 70 mmHg) with a given agent, and time to triggering was also independent of the order of exposure to the three anesthetics. Malignant hyperthermia susceptibility was confirmed in ten surviving animals, by both in vivo succinylcholine challenge and in vitro contracture testing. CONCLUSIONS: Although all three volatile anesthetics triggered MH, exposure to halothane resulted in significantly shorter times to MH triggering when compared with desflurane and isoflurane.     

Early detection of anastomotic leaks after colorectal surgery by measuring endotoxin in the drainage fluid

BACKGROUND/AIMS: Early detection of anastomotic leaks after colorectal anastomosis is essential for adequate intervention to prevent peritonitis. We investigated whether the measurement of endotoxin (LPS) concentrations in the drainage has any value for the early detection of anastomotic leaks. MATERIALS AND METHODS: Twenty two patients with colorectal anastomosis were enrolled in this study, 3 developed clinically established signs of anastomotic leaks and 19 recovered without complications. LPS concentrations in the drainage, the total daily excreted LPS amounts, leukocyte and thrombocyte counts, plasma urea and creatinine, and body temperature were measured for up to 8 days after surgery and tested for their value to detect anastomotic leaks. RESULTS: LPS concentrations in the drainage fluid and daily excreted LPS amounts of patients with anastomotic leaks were significantly higher compared to the group without anastomotic leaks. On the third postoperative day, LPS concentrations ranged from 5270 to 6750 pg/ml in patients with anastomotic leaks and from 1 to 1848 pg/ml in patients without complications. Total daily excreted LPS amounts were 270-675 ng/day in patients with anastomotic leak and 0-92 ng/day in patients without anastomotic leaks. Both LPS-related parameters allowed reliable detection of anastomotic leaks on day 3 after surgery (Student's t-Test, p < 0.0005), while leukocyte and thrombocyte counts, plasma urea and creatinine, and body temperatures of both patient groups were not significantly different at any time (p > 0.05). CONCLUSION: We found that the measurement of LPS concentrations in the drainage and the daily excreted LPS amount could be valuable parameters for the early detection of anastomotic leaks as early as on the third post-operative day.     

Mild hypothermia after cardiac arrest in dogs does not affect postarrest cerebral oxygen uptake/delivery mismatching

PURPOSE: To compare measurements of cerebral arteriovenous oxygen content differences (oxygen extraction ratios, oxygen utilization coefficients) in dogs after cardiac arrest, resuscitated under normothermia vs. mild hypothermia for 1-2 h or 12 h. METHODS: In 20 dogs, we used our model of ventricular fibrillation (no blood flow) of 12.5 min, reperfusion with brief cardiopulmonary bypass, and controlled ventilation, normotension, normoxemia, and mild hypocapnia to 24 h. We compared a normothermic control Group I (37.5 degrees C) (n = 8); with brief mild hypothermia in Group II (core and tympanic membrane temperature about 34 degrees C during the first hour after arrest) (n = 6); and with prolonged mild hypothermia in Group III (34 degrees C during the first 12 h after arrest) (n = 6). RESULTS: In Group I, the cerebral arteriovenous O2 content difference was 5.6 +/- 1.6 ml/dl before arrest; was low during reperfusion (transient hyperemia) and increased (worsened) significantly to 8.8 +/- 2.8 ml/dl at 1 h, remained increased until 18 h, and returned to baseline levels at 24 h after reperfusion. These values were not significantly different in hypothermic Groups II and III. The cerebral venous (saggital sinus) PO2 (PssO2) was about 40 mmHg (range 29-53) in all three groups before arrest and decreased significantly below baseline values, between 1 h and 18 h after arrest; the lowest mean values were 19 +/- 19 mmHg in Group I, 15 +/- 8 in Group II (NS), and 21 +/- 3 in Group III (NS). Postarrest PssO2 values of < or = 20 mmHg were found in 6/8 dogs in Group I, 5/6 in Group II and 4/6 in Group III. Among the 120 values of PssO2 measured between 1 h and 18 h after arrest, 32 were below the critical value of 20 mmHg. CONCLUSIONS: After prolonged cardiac arrest, critically low cerebral venous O2 values suggest inadequate cerebral O2 delivery. Brief or prolonged mild hypothermia after arrest does not mitigate the postarrest cerebral O2 uptake/delivery mismatching.     

Continuous low-flow tracheal gas insufflation during partial liquid ventilation in rabbits

BACKGROUND: Both partial liquid ventilation (PLV) and tracheal gas insufflation are novel techniques for mechanical ventilation. In this study we examined whether PLV superimposed by continuous low-flow tracheal gas insufflation (TGI) offers any advantage to the blood gases and lung mechanics in normal-lung rabbits compared to the use of PLV only. METHODS: Eighteen anesthetized, paralyzed and mechanically ventilated rabbits were used. After obtaining a baseline PaCO2 value between 29 and 39 mmHg (3.9 and 5.2 kPa), the animals were assigned to three equal groups according to the ventilation they received--A group: PLV superimposed by TGI; B group: PLV only; and C group: continuous mandatory ventilation (CMV) superimposed by TGI. Serial arterial blood gases, pH and lung mechanics were measured. RESULTS: The animals in each group were hemodynamically stable. In the case of the A group, PaO2 continuously increased, and PaCO2 stabilized around 40.8 +/- 5.5 mmHg (5.4 +/- 0.7 kPa, mean +/- SD, NS). In the B group, the tendency for PaO2 to increase was not as definite; PaCO2 continuously increased from 35.2 +/- 2.3 mmHg (4.7 +/- 0.3 kPa) to 56.3 +/- 12.7 mmHg (7.5 +/- 1.7 kPa, P < 0.05) at the end of the experiment. In the C group, PaO2 and PaCO2 were stable during the observation period. The superimposition of TGI on PLV did not decrease the airway pressures compared to PLV alone. CONCLUSION: In summary, continuous low-flow TGI superimposed on PLV can decrease and stabilize the PaCO2 elevation caused by the initiation of PLV.     

Esophageal anastomosis: an experimental model to study anastomotic healing and the use of lyophilized collagen

This experimental study assessed the use of lyophilized collagen to reinforce cervical esophageal anastomosis in rabbits. Twenty New Zealand White rabbits weighing 2.3-3.2 kg were used. In group I (n = 10) a 1-cm-long segment of the esophagus was excised and the two free edges anastomosed, to mimic the conditions found in newborn esophageal atresia. Group II (n = 10) had a segmental esophageal resection and end-to-end anastomosis as in group I but the anastomotic site was circumferentially covered with lyophilized type I collagen film. The resected segments were processed immediately and served as controls for the postoperative tissue in each animal. The animals were starved for the first 24 h and water was given on the 2nd postoperative day; on the 3rd postoperative day the animals were allowed a normal diet. Two rabbits in group II died on the 7th and 8th postoperative days because of a fistula. All the rabbits were killed on the 10th postoperative day and 4-cm segments of esophagus with the anastomosis at the centre were removed. At this time gross leakage was detected in four animals (one in group I and three in group II). Each anastomosis was evaluated for bursting pressure, collagen content, and histologic appearance. Bursting pressure was higher in group I. Collagen (measured as hydroxyproline) levels in anastomotic and adjoining 1-cm segments were compared with concentrations in control segments resected during operation. In group II animals there was a significant reduction in the lowering of hydroxyproline concentrations around the anastomosis. Microscopic evaluation revealed no significant differences between the two groups. This experiment showed no demonstrable benefit from the use of lyophilized collagen in preventing the esophageal anastomotic leakage that occurs in repaired esophageal atresia.     

Properties of the catalytic center of a secretory 28kDa protein (1-cys peroxiredoxin) from rat olfactory epithelium

BACKGROUND: Percutaneous mitral valvuloplasty with the Inoue balloon is conventionally performed with double vascular access: arterial and venous. However, in patients with a good echogenic window it may be performed with venous access only and the procedure monitored by 2D-echocardiography and colour flow mapping. This should result in early ambulation and hospital discharge with reduced arterial complications. AIMS: To compare retrospectively the immediate results of percutaneous mitral valvuloplasty with the Inoue balloon in two groups of patients: Group I: venous access only (no arterial access, n = 102) and Group II: conventional double vascular access (arterial and venous access, n = 275). METHODS AND RESULTS: The baseline characteristics of the two groups were comparable for age, sex, clinical, echocardiographic, radiological and haemodynamic variables. The mitral valve area (Group I: 1.1 +/- 0.3 to 1.85 +/- 0.5 cm2 vs Group II: 1.05 +/- 0.2 to 1.85 +/- 0.5 cm2, P = ns) and transmitral gradient (Group I: 11 +/- 4 to 4.7 +/- 2 mmHg vs Group II: 12 +/- 4 to 4.8 +/- 2 mmHg, P = ns) before and after mitral valvuloplasty were not statistically different. A good immediate result, defined as mitral valve area > 1.5 cm2 and mean mitral gradient < 5 mmHg with mitral regurgitation < or = 2+ at the end of the procedure, was observed in 77% of the cases in the venous-only group and 79% in the double access group (P = ns). The incidence of severe mitral regurgitation (Grade III or IV) was not statistically significant. Procedural duration (71 +/- 24 min vs 109 +/- 26 min, P < 0.01), fluoroscopic time (12.5 +/- 5.5 min vs 18.5 +/- 6 min, P < 0.01) and hospital stay (2.8 +/- 1.5 days vs 4.8 +/- 2.6 days, P < 0.001) were significantly shorter in the venous-only group than in the conventional Inoue series. CONCLUSION: Single venous access balloon mitral valvuloplasty is as equally safe and effective as double vascular access. The additional advantages of single venous access are shorter procedural duration, fluoroscopic time and hospital stay. We recommend that it be performed by an experienced operator (minimum of 100 trans-septal punctures) in patients without major thoracic deformity and a good echogenic window.     

Reversed-flow affinity elution applied to the purification of carboxypeptidase Y

BACKGROUND: Despite curative resection for colorectal cancer, many patients develop recurrence at the primary site or distant organs. These patients are candidates for (neo)-adjuvant chemotherapy. Very little is known about the effect of preoperative 5-fluorouracil (FU) on the healing of colonic anastomoses. The aim of this study was to assess this in a rat model. METHODS: Eighty male Wistar rats, weighing 160-215 g, were divided into three groups; (1) a control group underwent left colon resection and primary anastomosis (n = 20); (2) a sham group received 1 ml saline intraperitoneally (n = 30); (3) a study group received 5-FU intraperitoneally (20 mg kg-1). Both saline and 5-FU injections were given intraperitoneally for 5 days before operation. RESULTS: There was no difference in the rate of wound complications, intraperitoneal adhesions and anastomotic complications among the groups. Three and seven days after operation, mean bursting pressure of the anastomosis was 36.5 and 198 mmHg in group 1, 34 and 200 mmHg in group 2, and 39 and 190 mmHg in group 3 respectively (P not significant). Although the myeloperoxidase and hydroxyproline content were significantly lower after 5-FU therapy (P < 0.01, compared with others), the clinical outcome was similar. CONCLUSION: Preoperative 5-FU consecutive days before operation had no effect on the healing of colonic anastomoses.     

Successful retransplantation of mouse-to-rat cardiac xenografts under immunosuppressive monotherapy with cyclosporine

BACKGROUND: Total mesorectal excision (TME) is advocated for rectal cancer but the indications and extent of resection vary widely between surgeons. METHODS: Seventy-six consecutive patients (61 elective, 15 acute admission) with rectal or rectosigmoid cancer were admitted to a unit where TME was the preferred surgical option for potentially curative cancer at all levels of the rectum. RESULTS: Procedures undertaken were anterior resection (38 patients), abdominoperineal resection (18), Hartmann's procedure (ten) and transanal excision (one). Six patients had proximal faecal diversion alone and surgery was withheld in three. Anastomotic leaks occurred in six of 37 patients who had anterior resection with primary anastomosis, resulting in one early death. The presence of a proximal stoma did not influence the rate or seriousness of anastomotic dehiscence. After potentially curative TME in 45 patients, there have been eight local recurrences, four associated with systemic metastases and four which occurred in isolation (median follow-up 34 months). CONCLUSION: Curative TME was deemed appropriate in 59 per cent of unselected patients with rectal cancer. It was associated with few local recurrences but a morbidity rate that questions its role in treatment of upper third tumours.     

Change in glutathione S-transferase and glyceraldehyde-3-phosphate dehydrogenase activities in the organs of mice treated with 2-chloroethyl ethyl sulfide or its oxidation products

We have analyzed the immediate and mid-term (1 and 2 years) results of percutaneous mitral valvuloplasty (PMV) by Inoue's catheter in 97 patients < 60 years (Group A) compared with 34 patients > 60 years (Group B). In 61% Group A the patients were in NYHA functional class II, 36% in III, and 3% in I; in Group B, 56% of the patients were in NYHA functional class III, 38% in II, and 6% in IV. Mean mitral valve area was 1.1 cm2 before dilatation in both groups, and a significant (p < 0.0001) increase was obtained in both Group A (0.9 +/- 0.3 cm2) and Group B (0.8 +/- 0.3 cm2). No significant differences were observed between the two groups. Mean transvalvular gradient decreased significantly (p < 0.0001) from 13.6 +/- 5.7 to 7.2 +/- 3.1 mmHg in Group A, and from 9.9 +/- 4 to 6.5 +/- 2.3 mmHg in Group B (A vs B: p < 0.02). Optimal result was obtained in 94% and 88% of Group A and Group B patients, respectively. Suboptimal result was obtained in 2% and 6% of Group A and Group B patients, respectively. These differences were not significant. Failure of PMV occurred in 4% and 6%, respectively. At 1-year follow-up Group A 7 patients and 5 Group B patients showed restenosis; at 2-year follow-up one more restenosis was present in Group A (A vs B at 1 and 2 years: NS). We conclude that PMV is a safe and effective technique in young patients and in patients > 60 years.     

Functional outcome of patients with chronic obstructive pulmonary disease and exercise hypercapnia

Chronic hypercapnia is associated with a poor prognosis in chronic obstructive pulmonary disease (COPD). Some patients are normocapnic at rest but retain CO2 during exercise. The significance of this abnormality on the course of the disease is unknown. Sixteen stable COPD patients (13 males and 3 females, aged 60 +/- 5 yrs, mean +/- SD) who had previously undergone pulmonary function tests and progressive exercise testing with arterial blood sampling at rest and maximal capacity, entered the study. At first evaluation (E1), subjects were normocapnic at rest (arterial carbon dioxide tension (Pa,CO2): 4.9-5.7 kPa, (37-43 mmHg)) and all presented exercise-induced hypercapnia (end-exercise Pa,CO2 > 5.7 kPa (43 mmHg) with a minimal 0.5 kPa (4 mmHg) increase from resting value). The subjects were re-evaluated 24-54 months later (34 +/- 8 months) (second evaluation (E2)). At E2, forced expiratory volume in one second (FEV1) had decreased from 42 +/- 13 to 38 +/- 15% of predicted values, and mean resting Pa,CO2 had increased from 5.2 +/- 0.3 to 5.7 + 0.4 kPa. Maximal exercise capacity (Wmax) decreased between E1 and E2 from 76 +/- 30 to 56 +/- 22 W. Even if Wmax was lower at E2, end-exercise, Pa,CO2 was higher than at E1 (6.6 +/- 0.8 vs 6.4 +/- 0.5 kPa). At E2, eight subjects presented resting hypercapnia (group H), whilst the others remained normocapnic (Group N). Group H subjects had higher Pa,CO2, at Wmax than Group N and lower Wmax than Group N at E2.(ABSTRACT TRUNCATED AT 250 WORDS)     

Usefulness of ultrasound-guided prostate biopsy in the diagnosis and treatment of localized prostate cancer

OBJECTIVE: To evaluate the safety and efficacy of stapled anastomosis in left sided colorectal reconstructions. DESIGN: Prospective study. SETTING: District hospital, UK. SUBJECTS: 218 Consecutive patients who underwent elective colorectal reconstructions with stapled anastomoses between July 1980 and July 1994. INTERVENTIONS: 154 Anterior resections of the rectum using single or double stapled anastomoses, 37 rejoining after Hartmann's operations, and 28 restorative proctocolectomies with formation of J pouch ileoanal anastomoses. MAIN OUTCOME MEASURES: Morbidity and mortality. RESULTS: There were 5/154 clinical anastomotic leaks after anterior resection of the rectum and 1/28 after stapled J pouch ileoanal anastomoses. There were no leaks after rejoining of Hartmann's. The overall clinical leak rate was therefore 3%. 11/154 tumours recurred locally after anterior resection of the rectum (7%) during a mean follow up of 18 months, and 8 (73%) developed within 2 years of operation. All but one recurrence developed after single stapled anastomosis. Dukes' staging remains the most reliable prognostic indicator of the local recurrence of the tumour. There were five postoperative deaths after anterior resection but none after Hartmann's procedure or J pouch ileoanal anastomosis, giving an overall postoperative mortality of 2.3%. CONCLUSION: The use of stapling instruments in left sided colorectal anastomosis is safe and technically easy, with a low clinical anastomotic leak rate and an acceptable rate of local recurrence after anterior resection of the rectum.     

The effect of octreotide on wound healing: an in vitro and in vivo experimental study

OBJECTIVE: To investigate the effect of octreotide on wound healing. DESIGN: Experimental studies in vitro and in rats. SETTING: Teaching hospital, Israel. MATERIAL: Cultured human diploid fetal fibroblasts, and 36 male Wistar rats. INTERVENTIONS: Octreotide was added to cultures of fibroblasts in doses of 2, 10, 30, 60 and 120 ng/ml and fibroblasts were counted after 2, 4, and 6 days. Intestinal anastomoses were made in 36 rats. Rats in the octreotide group (n = 18) were given subcutaneous injections of 0.25 microg/kg twice daily and 6 rats were killed at 3, 7, and 14 days. The control group were given injections of saline. Anastomotic bursting pressures and hydroxyproline content were measured at each of the three times. MAIN OUTCOME MEASURES: Fibroblast counts, anastomotic bursting pressures, and hydroxyproline concentrations. RESULTS: Octreotide did not inhibit fibroblast proliferation in any of the doses at any of the time periods. The anastomotic bursting pressure was slightly higher in the octreotide group at each of the time points, but not significantly so, and there was no difference in hydroxyproline content between the octreotide and control groups. Octreotide did not inhibit wound healing either in vitro or in vivo.     

Partial cardiopulmonary bypass in rats for evaluating ischemia-reperfusion injury

The authors developed a miniaturized partial cardiopulmonary bypass model in rats by using membrane oxygenators. Sprague-Dawley rats underwent general anesthesia and tracheostomy for ventilation. Partial cardiopulmonary bypass was carried out through the jugular cannula (18 gauge) for venous blood drainage and through the femoral arterial cannula (24 gauge) at a flow of 50 ml/kg/min. Membrane oxygenators used in this study maintained arterial oxygen tensions (PaO2) at 300-500 mmHg and carbon dioxide tensions (PaCO2) at 25-35 mmHg, with a gas mixture of 95% O2 + 5% CO2 (n = 7) for at least 2 hr of bypass circulation. To test the feasibility of this system for investigation of ischemia-reperfusion injury, hypoxic challenges with gas mixtures of different oxygen concentrations were examined. After equilibration of the bypass circulation for 1 hr, the following gases were tested for 15 min: Group I, 95% air + 5% CO2 (FiO2 = 0.21, n = 5); Group II, 10% O2 + 5% CO2 + 85% N2 (FiO2 = 0.1, n = 5); and Group III, 95% N2 + 5% CO2 (FiO2 = 0, n = 5). Equilibrated PaO2 values after challenge with these gases for 15 min were as follows: Group I: 89.6 +/- 3.7, Group II: 53.8 +/- 1.4, Group III: 25.6 +/- 2.0 mmHg (p < 0.01 between Groups I and II, I and III, II and III; p < 0.01 vs. prehypoxic PaO2 values in all groups). PaO2 values returned to the previous level within 15 min after return to the standard gas mixture (95% O2 + 5% CO2) supply. This system provided stable cardiopulmonary bypass in rats for at least 2 hr and may be useful for investigation of ischemia-reperfusion injury.     

Effect of casemix funding on outcomes in patients admitted to hospital with suspected unstable angina

This study was undertaken to assess the appropriate management of patients with diverticulitis complicated by fistula formation. A retrospective chart review was conducted on patients with symptoms of a fistula who presented between 1975 to 1995. There were 42 patients (32 women, 76%; 10 men, 24%) who ranged in age from 46 to 89 years (mean 69.8 +/- 9.8). Six patients had multiple fistulas. The types of fistulas included colovesical (48%), colovaginal (44%), colocutaneous (4%), colotubal (2%), and coloenteric (2%). Operative procedures consisted of resection and primary anastomosis in 38 patients and a Hartmann's operation in one. Three patients were managed conservatively with antibiotics (two due to poor performance status, the third due to resolution of symptoms). There were no operative deaths. The postoperative course was uncomplicated in 69%, while 12 patients (31%) experienced 19 complications (40%). These consisted of urinary tract infection (9.5%), atelectasis (7.1%), prolonged ileus (4.8%), arrhythmias (4.8%) and renal failure, myocardial infarction, pseudomembranous colitis, peroneal nerve palsy, unexplained fever, pulmonary edema (2.4% each). There were no anastomotic leaks and no deaths. Hospital stay ranged from 6 to 31 days (mean 12.3 +/- 7.6). Fistulas due to diverticulitis were safely managed by resection and primary anastomosis without mortality and with acceptable morbidity in this series. Patients deemed to be poor operative risks can be managed with a course of nonoperative treatment.     

Bursting pressure in anastomotic healing in experimentally induced colitis in rats

BACKGROUND: Experimental studies on healing of colonic anastomosis have been thoroughly investigated. However, clinical parameters of the healing process of anastomosis in the inflamed colon has not yet been reported. METHODS: In the present study, healing of anastomosis in trinitrobenzene-sulfonic acid-induced colitis in rats was assessed by measuring the bursting pressure and bursting wall tension. RESULTS: On postoperative day 4, bursting pressure and bursting wall tension were significantly lower (P < 0.001) in rats with colitis with or without anastomosis and normal colon with anastomosis, compared with normal colon without anastomosis. On postoperative day 7, bursting pressure and bursting wall tension of normal colon with anastomosis approached that of normal colon without anastomosis. However, bursting pressure and bursting wall tension of rats with colitis with or without anastomosis remained significantly lower (P < 0.001) than the latter. Furthermore, unlike rats without colitis in which perforation occurred mostly at the anastomotic line, the bursting site in colitic rats was predominantly away from the anastomotic line. CONCLUSIONS: These results suggest that in surgery for inflammatory bowel disease, it is the adjoining inflamed bowel wall that is vulnerable to be perforated in response to increasing intraluminal pressure rather than the anastomosis that is braced by the sutures.