24-hour rabbit heart storage with UW solution. Effects of low-flow perfusion, colloid, and shelf storage.

A new technique for 24-hr cardiac preservation is described utilizing very low flow perfusion (microperfusion) with a cold flush solution. Rabbit hearts were arrested with UW solution and then perfused with the same solution through the aortic root at 0 degrees C at a rate of 3-6 ml/gm heart weight/24 hr. When tested on an ex vivo working heart model, the cardiac output (CO) was 28.72 +/- 7.69 ml/g/min compared with fresh UW flushed controls of 26.48 +/- 2.25 ml/g/min. Both oxygenated highflow perfusion with a more conventional perfusate and 24-hr ice storage with UW led to inferior results. Omission of the colloid, hydroxyethyl starch (HES), from the UW solution or prolonged shelf storage were also significantly detrimental. When a previously untested colloid, polyethylene glycol 20,000, was substituted for HES for microperfusion, excellent cardiac function was obtained. In fact, the mean CO of this group, 31.91 +/- 5.70, was significantly above that of fresh HES-UW unstored controls. The suggestion that the UW solution might be improved by this substitution warrants further study.

Pharmacological protection of rabbit kidneys from normothermic ischemia.

This study investigated the influence of the administration of pharmacological agents on the recovery of rabbit kidneys from the effects of 1 hr of situ normothermic ischemia, utilizing acute and chronic models. The agents tested included the diuretics mannitol and furosemide, the vasoactive agents phenoxybenzamine, propranolol, and dopamine, and the membrane stabilizers chlorpromazine and methylprednisolone. A beneficial effect was detected only with the diuretic agents and propranolol when given prior to the ischemic insult.

Optimal cardioplegia and 24-hour heart storage with simplified UW solution containing polyethylene glycol.

Recent work has shown that UW may be better than standard cardioplegic solutions for short-term heart preservation. In this study we have used a rabbit heart model to evaluate a simplified UW solution in which penicillin, dexamethasone, insulin, allopurinol, and adenosine were omitted and 5% polyethylene glycol (PEG20M) was substituted for hydroxyethyl starch. The test systems consisted of 4-hr cardioplegic storage at 15 degrees C with repeated flushing every 30 min for 2 hr and 24-hr hypoxic low-flow microperfusion (3 ml/g/24 hr) at 0 degrees C. Control groups were arrested with a 15-25 ml flush in iced saline and immediately tested. Cardiac output (CO)* after preservation was measured in a working heart model using an acellular perfusate at 37 degrees C at an aortic pressure of 100 cm H2O. The CO (ml/g heart wt/min) were as follows--Controls: St. Thomas II 20.5 +/- 8.3 (5), UW 34.7 +/- 11.7 (16), PEG20M 41.8 +/- 4.4 (14); 4-hr cardioplegia: St. Thomas II 17.4 +/- 0.9 (4), Bretschneider HTK 14.9 +/- 7.0 (4), UW 25.2 +/- 11.5 (9), PEG20M 41.1 +/- 7.8 (8); 24-hr microperfusion: UW 25.4 +/- 11.1 (18), PEG20M 37.1 +/- 8.2 (18). Following cardioplegic or microperfusion preservation, PEG20M hearts functioned at control levels (P greater than 0.05) and were significantly superior to all other solutions, with approximately double the CO (P less than 0.05, all other groups). We conclude that for heart preservation, 5 components can be eliminated from UW and substitution of PEG20M for HES appears to have improved its performance.

Calcium antagonists in sodium lactobionate sucrose solution for rat liver preservation.

The effects of the calcium antagonists, chlorpromazine (CPZ), nisoldipine (NIS), trifluoperazine (TFP), and nicardipine (NIC) were compared in rat livers following either 20- or 30-hr ice storage in sodium lactobionate sucrose solution (SLS). Survivals beyond 7 days after orthotopic liver transplantation following 20-hr cold storage were 1/14 in the University of Wisconsin solution, 4/14 in SLS, 4/8 in UW+CPZ, 7/8 in SLS+CPZ. Survivals beyond 7 days after OLT following 30-hr cold storage were 3/8 in SLS+CPZ, 3/8 in SLS+NIS, 2/8 in SLS+TFP, 0/8 in SLS+NIC, and 0/8 in SLS alone. Survival rates were significantly (P less than 0.05) better in both SLS+CPZ and SLS+NIS than in UW and SLS alone. The effluent lactate dehydrogenase (LDH) levels and pH changes were measured at the time of OLT. After 20 hr, LDH levels were 525 +/- 78 IU/L (mean +/- SEM) in UW, 492 +/- 44 in SLS, 322 +/- 35 in UW+CPZ, and 290 +/- 39 in SLS+CPZ. After 30 hr, LDH values were 416 +/- 40 in SLS+CPZ, 450 +/- 25 in SLS+NIS, 448 +/- 21 in SLS+TFP, 573 +/- 18 in SLS+NIC, and 614 +/- 68 in SLS. The LDH levels for SLS+CPZ and SLS+NIS were significantly lower than those of SLS and UW (P less than 0.01). The pH changes in the effluent were significantly less in both the CPZ and NIS groups (P less than 0.01). This study demonstrated improved liver preservation by the use of a simplified colloid-free lactobionate solution containing sodium as the principal cation. The addition of CPZ or NIS to the solution demonstrated the same potency for significant improvement in efficacy of this solution, while NIC was ineffective.

Improved function of perfused rabbit kidneys by prevention of oxidative injury.

This study explored the effect of adding small amounts of the reducing agents ascorbic acid and glutathione to a Ringer's-albumin perfusate used for 24-hr hypothermic perfusion of rabbit kidneys. Maintenance of function during preservation was evaluated with a shunt perfusion model and by measuring the ability of cortical slices to restore normal K/Na ratios after incubation in a electrolyte medium. When placed in contact with the unmodified perfusate, an electrode of pyrolytic carbon registered a potential of +190 mV relative to the silver-silver chloride couple. This reading fell rapidly by 100-125 mv when kidneys were placed on the circuit. The mean creatinine clearance after 24-hr perfusion was significantly improved from 162 +/- 56 ml/hr in controls to 284 +/- 92 ml/hr when the potential indicated by this electrode was preadjusted to 43-54 mv with reducing agents, and to 237 +/- 62 ml/hr when this adjustment was made after 2 hr. These creatinine clearances were similar to those of kidneys stored on ice for only 1 hr. These findings indicate minimal injury occurred in the chemically reduced groups and emphasize the importance of preventing oxidative damage to kidneys during hypothermic organ perfusion. The time course of the changes in potential registered by this electrode was consistent with our previous finding that much of the damage to perfused kidneys occurs very early in the course of perfusion. The tissue slice studies showed no detectable damage to the renal parenchyma of the kidneys in the control group despite diminished creatinine clearance. This suggests that the site of oxidation injury is the vascular compartment.

Significance of terminal rinse for rat liver preservation.

A terminal rinse (TR) is standard practice in liver preservation with University of Wisconsin solution (UW) to avoid a potassium load. The fact that sodium lactobionate sucrose solution (SLS) is an effective organ preservation solution with a low potassium provided an opportunity to evaluate rat liver preservation without the TR step. Its importance was investigated in 122 rat liver preservation experiments. In study 1, UW and a hydroxyethyl starch-free, modified UW (UWm) were used for 20-hr liver preservation followed by either no TR or Ringer's lactate TR. The 1-week survival was: UW-TR, 2/14; UW-no TR, 1/6; UWm-TR, 0/6; UWm-no TR, 5/5 (P < 0.01). In study 2, livers were stored for 30 hr in SLS, UW, UWm, and UWm + chlorpromazine 5 mg/L, all without a TR. Nine of 11 rats survived 7 days after SLS, but there were no survivors in the other groups (P < 0.05). Study 3 compared no TR with TR with SLS, Ringer's lactate (RL), or a modified Carolina rinse (CRm) after 30-hr SLS preservation. Survival, serum aspartate aminotransferase and alanine aminotransferase, and histology were assessed. One-week survival of 9/11 rats in no TR was significantly better than in the other groups (3/14 in TR-SLS, 0/8 in TR-RL, and 0/14 in TR-CRm, P < 0.01). The values of aspartate aminotransferase (mean +/- SE) 3 hr after transplantation were 1862 +/- 439 U/L, 3334 +/- 817 U/L, 6591 +/- 1944 U/L, and 7028 +/- 1704 U/L, respectively, in no TR, TR-SLS, TR-RL, and TR-CRm. There were significant differences both in aspartate aminotransferase and alanine aminotransferase between no-TR and each of TR-RL and TR-CRm (P < 0.05). Liver specimens from rats killed 3 hr after OLT showed only mild injury in the no TR group and severe injury in the remaining groups. We conclude that a terminal rinse is harmful in rat liver preservation.

Studies of the ideal [H+] for perfusional preservation.

The neutral point of water, being a function of its dissociation constant, is temperature dependent. This is also true of protein-buffered solutions such as perfusates. In organ preservation these facts have been long ignored and, as a result, perfusions have been carried out in a relatively acidotic environment. These studies evaluated the effects of correcting the pH partially or completely for the level of hypothermia involved in perfusional preservation. The findings both in rabbits and dogs were that a pH of 7.4 (measured at 7 C) is dangerously close to the pH below which there is rapid deterioration of function. On the other hand, perfusate pHs up to 7.75 in dogs and 8.25 in rabbits were tolerated at no detriment. As a result, the recommendation is made to carry out hypothermic organ perfusion at a pH well above 7.4; 7.60 or 7.65 seems reasonable.

Warm ischemic injury of the lung.

Canine left lower lobes which were subjected to 3 hours of warm ischemia in an atelectatic condition were compared to lobes which had not been stored. During short-term reimplantation studies, the injured lobes were characterized by marked weight gain, diminution in blood flow, increased vascular resistance, and peak airway pressure. The ventilation/perfusion ratios were high and considerable dead-space ventilation was present. Hypoxic vasoconstriction occurred in both control and stored lobes, and shunt determinations did not vary because of the low blood flows observed. Some or all of these physiological changes may serve to develop a simple screening method to evaluate techniques of pulmonary preservation.

Twenty-four-hour ice storage of rabbit heart.

Although cardioplegia is limited to 4 hours of ice storage, University of Wisconsin solution has successfully extended this period to approximately 12 hours. In this study we have substituted polyethylene glycol for hydroxyethyl starch in a simplified University of Wisconsin solution (Cardiosol). Rabbit hearts were ice stored for 24 hours at 0 degrees C in either University of Wisconsin solution or Cardiosol (containing either 5% or 10% polyethylene glycol). Fresh control hearts were tested immediately after cardiectomy. Function was evaluated in an in vitro working heart model for 1 hour with aortic afterload at 100 cm H2O. Total cardiac output or the proportion of hearts reaching 100 cm H2O were compared. Hearts stored in University of Wisconsin solution for 24 hours functioned at 6% of control levels at 15 minutes of observation. None reached 100 cm H2O or deteriorated further with time (p < 0.05). By contrast, hearts stored in 5% Cardiosol showed progressive recovery during the 1-hour observation. Of the 13 hearts, 11 reached 100 cm H2O with a mean cardiac output of 51% of the control value. Increasing the concentration of polyethylene glycol to 10% improved cardiac output at all observation times, reaching 80% of control heart performance at 1 hour (control > 10% > 5% > University of Wisconsin solution [p < 0.05]). We concluded that 10% polyethylene glycol significantly improved 24-hour ice storage and, hence, viability to a functional level that matched our previously reported microperfusion results.

Cardiotonic effects of reduced sulfhydryl amines after preservation of rabbit hearts.

This investigation was designed to examine the role of glutathione and other reduced sulfhydryl amines during reperfusion of the ischemic rabbit heart. To identify the biochemical features of reduced sulfhydryl amines contributing toward improved myocardial function, we investigated several chemical agents sharing a common property with glutathione (L-leucine, L-glycine, ascorbate, oxidized glutathione, L-cysteine). After a period of 24-hour hypothermic storage of the rabbit heart in a modified University of Wisconsin solution containing polyethylene glycol, the hearts were functionally evaluated on a Langendorff working heart model. The agents were then injected as a bolus (60 mumol/L) during reperfusion, and coronary flow and aortic output were measured. Control hearts were untreated. Reduced sulfhydryl amines (glutathione, L-cysteine) significantly improved coronary flow (p < 0.005) and cardiac output (p < 0.005). Ascorbate, L-leucine, L-glycine, and oxidized glutathione all failed to influence cardiac function.

Forty-eight hour ice storage of kidneys: importance of cation content.

The importance of the cation content of flush solutions used for simple hypothermic storage has been investigated in a 48 hour canine kidney preservation model. Uniformly successful 48 hour storage was achieved with solution C2. However, inclusion of procaine (0.1 Gm. per 100 ml.) in the flushing solution as in C3 produced significant kidney damage. Without procaine, Sacks solution was no better than was C2 and the latter proved significantly superior to a sodium-based solution having identical anion content and osmolarity. The magnesium content of the sodium appeared to favorably influence the outcome of the kidney storage experiments.

Successful 20-hour rat liver preservation with chlorpromazine in sodium lactobionate sucrose solution.

We investigated the effect of the addition of chlorpromazine to a new, simplified organ preservation solution, sodium lactobionate sucrose (SLS), for 20-hour hypothermic rat liver preservation. Survival beyond 7 days after orthotopic transplantation of the stored liver was eight of eight rats in control groups (immediate transplantation, less than 1-hour preservation), one of 14 rats with the University of Wisconsin (UW) solution, four of 14 rats with SLS, seven of eight rats with SLS + chlorpromazine, 1 mg/L, and seven of eight rats with SLS + chlorpromazine, 10 mg/L. The differences is survival between UW and SLS and between SLS and SLS + chlorpromazine were significant (p less than 0.05). Lactic dehydrogenase levels in the effluent after reflushing through the portal vein at the time of transplantation were 145 +/- 20 IU/L (mean +/- SEM) in the controls, 525 +/- 78 IU/L in UW, 492 +/- 44 IU/L in SLS, 290 +/- 39 IU/L in SLS + chlorpromazine, 1 mg/L, 290 +/- 11 IU/L in SLS + chlorpromazine, 10 mg/L. The values for the SLS + chlorpromazine were significantly lower than for SLS and UW (p less than 0.05). The pH of the effluent was 7.10 +/- 0.10 in controls, 6.42 +/- 0.12 in UW, 6.64 +/- 0.18 in SLS, and 7.07 +/- 0.02 in SLS + chlorpromazine, 1 mg/L and 10 mg/L. The pH drop was significantly greater in the groups without chlorpromazine (p less than 0.01). This study shows that superior rat liver preservation was achieved with a simplified lactobionate solution containing sodium as the principal cation, sucrose in place of raffinose, and omitting the colloid and several of the other UW components. The addition of low concentrations of chlorpromazine further enhanced the effectiveness of this solution, without the need for donor pretreatment.

Total abdominal evisceration: an en bloc technique for abdominal organ harvesting.

This paper describes an en bloc total abdominal evisceration (TAE) technique that has been used successfully in 81 consecutive multi-organ procurements in donors ranging from 2.5 to 85 kg. Preliminary dissection performed by the surgeon and physician's assistant averaged 30 to 45 minutes before aortic cross-clamping. Removal of all abdominal organs (liver, kidneys, pancreas, bowel) en bloc averaged 16 to 24 minutes after aortic cross-clamping, depending on the speed of the thoracic procurement. Organ grafts were preserved with the University of Wisconsin preservation solution. Total procurement time for the removal of the liver, pancreas, and kidneys averaged 1.5 to 2.25 hours. Because all vascular anomalies were easily recognized ex vivo, vascular reconstruction was possible, so that all donors could potentially provide for combined liver, pancreas, and kidney transplantation. In the TAE group, primary liver graft nonfunction was 1.2% (1/81 grafts), which is less than the non-TAE liver graft nonfunction rate of 7% (7/99 grafts); this is statistically significant (p less than 0.05). Also, the incidence of fresh frozen plasma support after liver transplantation in the TAE group (2/81 transplantations) was lower than the non-TAE group (9/99 transplantations) (p less than 0.05). The overall liver recipient survival rate was 87% (non-TAE; 78/94 recipients; TAE; 65/70 recipients). Kidney-graft initial function has been similar in both the TAE and non-TAE groups. All pancreas tissue was histologically normal, and extraction of viable islet cells (average, 3600 islets per gram pancreas) was possible with yields similar to standard pancreatic (average, 379 islets per gram pancreas) harvest techniques. Preliminary experience with combined liver and whole-organ pancreas transplantations has been encouraging, with immediate discontinuation of intraoperative insulin during transplantation.

New organ preservation solutions.

In 1969 we described a method for kidney preservation that used a brief flush with a new "intracellular" solution followed by ice storage. This paper stimulated research into optimizing solution composition culminating in the UW solution which is now the accepted standard. Further developments in the design of solutions for hypothermic organ preservation have proceeded along several paths, including: (1) modification and simplification of UW solution, (2) investigation of organ specific requirements, (3) addition of pharmacologic agents particularly calcium antagonists to flush solutions, (4) the concept of "microperfusion" for control of acidosis, (5) the use of solutions containing polyethylene glycol, and (6) the use of a terminal rinse solution. Broadly speaking, the results of these studies have shown that it is possible to improve upon the UW solution by simplification, eliminating several of the components, and that sodium variants, and pharmacological additives, such as chlorpromazine, may yield better results in experimental and clinical trials. It has also been found that there are special requirements for individual organs, rendering the concept of a universal solution unlikely. Of the promising new ideas, microperfusion and polyethylene glycol have been found to be very effective for heart preservation yielding for the first time virtually perfect 24-hour preservation. The concept of a terminal rinse to diminish reperfusion injury has strong experimental support and awaits clinical evaluation.

Forty-eight-hour kidney preservation. A comparison of flushing and ice storage with perfusion.

Cold nonperfusional (flushing and ice storage) with Collins or Sacks solution and perfusional preservation with cryoprecipitated plasma or albumin were compared in dog kidneys. All these methods were effective in achieving excellent 48-hour preservation of fresh kidneys. After exposure to 20 minutes of ischemia at 37 C, neither of the flushing solutions yielded kidneys that permitted survival of recipients after 48 hours of preservation, and flushed kidneys functioned poorly after 24 hours of preservation. In contrast, both plasma- and albumin-perfused kidneys exposed to ischemia supported life satisfactorily and with normal function. Therefore, simple and inexpensive flushing and ice storage techniques are entirely satisfactorily for the preservation of ideally harvested cadaver kidneys, while the more complex and expensive perfusional techniques must be employed in preserving ischemia-damaged organs.

Transplant renal artery stenosis occurring in both recipients from a single donor.

Stenosis of the renal artery is increasingly being recognized as a cause of hypertension and renal failure after kidney transplantation. To our knowledge, this is the first report of an almost simultaneous occurrence of this complication in both recipients of kidneys from a single donor. In both cases, surgical correction led to improved renal function and amelioration of the hypertension.

Nonaneurysmal suppurative aortitis.

Two patients had nonaneurysmal suppurative aortitis. In one, the aortic ruptured and the patient died. The second patient had Salmonella sepsis and occlusion of the infrarenal aorta. He was treated with aortic resection and extra-anatomic bypass, but died 20 months later of an unrelated illness. Patients with Salmonella sepsis who are over 50 years of age or who are suspected of having aortic atherosclerosis should be evaluated carefully for aortitis since rupture or aneurysm formation is associated with a dismal prognosis.

Changing patterns of gastrointestinal bleeding.

This study, a retrospective analysis of 351 patients with acute gastrointestinal (GI) hemorrhage, was undertaken to define patterns of disease and age-related operative and mortality rates and to determine changes over time related to changes in management. One third (116 patients) of the admissions had bleeding esophageal varices. Upper GI hemorrhage accounted for 85% (N = 200) and lower GI hemorrhage for 15% (N = 35). Emergency surgical intervention was required in 90 patients (38%), 40% of the upper and 29% of the lower GI hemorrhage patients. Benign ulcer disease accounted for 86% of the cases requiring emergency surgery and was treated with vagotomy and drainage and/or oversewing. Lower GI bleeding is seen in older patients; it has a lower operative intervention rate and a higher mortality. Stress bleeding as a surgical lesion has disappeared since 1979. A more assertive policy for surgical intervention has decreased operative mortality for all age groups. Bleeding duodenal ulcers are decreasing in incidence while gastric lesions appear to be increasing. These population-specific patterns, different from earlier periods, may have implications for training and patient management decisions.

Transplant renal artery thrombosis. Revascularization after 51/2 hours of ischemia.

Restoration of blood flow to a transplanted kidney following renal artery thrombosis should provide a good model for determining the tolerance of the human kidney to normothermic ischemia. Two cases were seen in which function returned after two and 51/2 hours of occlusion. These, together with two other similar cases reported previously, suggest that attempted revascularization is worthwhile even after several hours of ischemia.

Is carotid endarterectomy beneficial in prevention of recurrent stroke?

Of 456 consecutive carotid endarterectomies performed at the University of California, San Diego, 127 were in patients who had sustained a previous completed stroke and had recovered with minimal but permanent neurologic deficits (PNDs). Operative mortality for the entire series was 0.9%, but it was 3.1% for the stroke group. A postoperative PND was observed in 2.1% of patients without neurologic deficits but occurred in 3.9% of the patients after stroke. A 97% one-to-ten-year follow-up was obtained. The total early and late serious morbidity and mortality in this surgically treated series of patients after stroke was 24% at five years. We conclude that carotid endarterectomy for the prevention of recurrent stroke carries a high risk and may not be superior to nonoperative treatment.