Wound ballistics and blast injuries

Wounds due to gunshot and explosions, while usually observed during battlefield combat, are no longer an exceptional occurrence in civilian practice in France. The principles of wound ballistics are based on the interaction between the projectile and the human body as well as the transfer of energy from the projectile to tissues. The treatment of ballistic wounds relies on several principles: extremity wound debridement and absence of initial closure, complementary medical treatment, routine immobilization, revision surgery and secondary closure. Victims of explosions usually present with a complex clinical picture since injuries are directly or indirectly related to the shock wave (blast) originating from the explosion. These injuries depend on the type of explosive device, the environment and the situation of the victim at the time of the explosion, and are classed as primary, secondary, tertiary or quaternary. Secondary injuries due to flying debris and bomb fragments are generally the predominant presenting symptoms while isolated primary injuries (blast) are rare. The resulting complexity of the clinical picture explains why triage of these victims is particularly difficult. Certain myths, such as inevitable necrosis of the soft tissues that are displaced by the formation of the temporary cavitation by the projectile, or sterilization of the wounds by heat generated by the projectile should be forgotten. Ballistic-protective body armor and helmets are not infallible, even when they are not perforated, and can even be at the origin of injuries, either due to missile impact, or to the blast.

Fixed-Distance Model for Balloon Placement During Fluoroscopy-Free Resuscitative Endovascular Balloon Occlusion of the Aorta in a Civilian Population

Importance

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an innovative procedure in the treatment of noncompressible truncal hemorrhage. However, readily available fluoroscopy remains a limiting factor in its widespread implementation. Several methods have been proposed to perform REBOA without fluoroscopic guidance, and these methods were adapted predominantly from the military theater.

Objective

To develop a method for performing REBOA in a civilian population using a standardized distance from a set point of entry.

Design, Setting, and Participants

A retrospective study of whole-body computed tomographic (CT) scans from a cohort of 280 consecutive civilian trauma patients from University Hospitals of Lyon, France, was used to calculate the endovascular distances from both femoral arteries at the level of the upper border of the symphysis pubis to aortic zone I (descending thoracic aorta) and zone III (infrarenal aorta). These whole-body CT scans were performed between 2013 and 2015. Data were analyzed from July 16 to December 7, 2015.

Main Outcomes and Measures

Two segments (1 per zone) common to all CT scans were isolated, and their location, length, prevalence in the cohort, and predicted prevalence in the general population were calculated by inverting 99% certainty tolerance limits.

Results

Among the 280 trauma patients (140 men and 140 women) in this study, the mean (SD) height was 170.7 (8.7) cm, and the mean (SD) age was 38.8 (16.5) years. The common segment in zone I (414-474 mm) existed in all CT scans. The common segment in zone III (236-256 mm) existed in 99.6% and 97.9% of CT scans from the right and left femoral arteries, respectively. These segments are expected to exist in 98.7% (zone I) and 94.9% (zone III) of the general population.

Conclusions and Relevance

Target distances for blind placement of REBOA exist with more than 94% prevalence in a civilian population. These findings support the expanded use of REBOA in emergency department and prehospital settings. Validation for safety and efficacy on cadaveric and clinical models is necessary.

Abbreviated laparotomy or damage control laparotomy: Why, when and how to do it?

The goal of abbreviated laparotomy is to treat severely injured patients whose condition requires an immediate surgical operation but for whom a prolonged procedure would worsen physiological impairment and metabolic failure. Indeed, in severely injured patients, blood loss and tissue injuries enhance the onset of the "bloody vicious circle", triggered by the triad of acidosis-hypothermia-coagulopathy. Abbreviated laparotomy is a surgical strategy that forgoes the completeness of operation in favor of a physiological approach, the overriding preference going to rapidity and limiting the procedure to control the injuries. Management is based on sequential association of the shortest possible preoperative resuscitation with surgery limited to essential steps to control injury (stop the bleeding and contamination), without definitive repair. The latter will be ensured during a scheduled re-operation after a period of resuscitation aiming to correct physiological abnormalities induced by the trauma and its treatment. This strategy necessitates a pre-defined plan and involvement of the entire medical and nursing staff to reduce time loss to a strict minimum.

Kendrick's extrication device and unstable pelvic fractures: Should a trochanteric belt be added? A cadaveric study

INTRODUCTION

Pre-hospital pelvic stabilisation is advised to prevent exsanguination in patients with unstable pelvic fractures (UPFs). Kendrick's extrication device (KED) is commonly used to extricate patients from cars or crevasses. However the KED has not been tested for potential adverse effects in patients with pelvic fractures. The aim of this study was to examine the effect of the KED on pubic symphysis diastasis (SyD) with and without the use of a trochanteric belt (TB) during the extraction process following a MVC.

MATERIALS AND METHODS

Left-sided "open-book" UPFs were created in 18 human cadavers that were placed in seven different positions simulating pre-extraction and extraction positions using the KED with and without a TB in two different positions (through and over the thigh straps). The SyD was measured using anteroposterior radiographs. The effects of the KED with and without TB, on the SyD, were evaluated.

RESULTS

The KED alone resulted in a non-significant increase of the SyD compared to baseline, whereas the addition of a TB to the KED resulted in a significant reduction of the SyD (p<0.001). The TB through the straps provided a significantly better reduction than the TB over the straps in the extracted position (p<0.05).

CONCLUSION

Our study demonstrated that a TB in combination with the KED on UPFs is an effective way to achieve early reduction. The addition of the TB in combination with the KED could be considered for Pre-Hospital Trauma Life Support (PHTLS) training protocols.

Clamshell incision versus left anterolateral thoracotomy. Which one is faster when performing a resuscitative thoracotomy? The tortoise and the hare revisited

BACKGROUND

The clamshell incision (CI) offers a better exposure than the left anterolateral thoracotomy (LAT) as a resuscitative thoracotomy. Most surgeons will have to manage a heart wound only once or twice in their career. The patient's survival depends on how fast the surgeon can control the heart wound; however, it is unclear which of the two incisions allows for faster control in the hands of inexperienced surgeons. The aim of this study was to compare the time needed to access and control a standardized stab wound to the right ventricle, by inexperienced surgical trainees, by LAT or CI; we hypothesized that the CI does not take longer than the LAT.

METHODS

Sixteen residents were shown a video on how to perform both procedures. They were randomly assigned to control a standardized stab wound of the right ventricle on perfused human cadavers by LAT (n = 8) or CI (n = 8). Access time (skin to maximal exposure), control time (maximal exposure until control of the heart wound) and total time (the sum of access and control times) were recorded.

RESULTS

Total time was 6.62 min [3.20-8.14] (median [interquartile range]) for LAT and 4.63 min [3.17-6.73] for CI (p = 0.46). Access time was 2.39 min [1.21-2.76] for LAT and 2.33 min [1.58-4.86] for CI (p = 0.34). Control time was 4.16 min [2.32-5.49] for LAT and 1.85 min [1.38-2.23] for CI (p = 0.018).

CONCLUSIONS

The time needed from skin incision until cardiac wound control via CI was not longer than via LAT and the easier control of the cardiac wound when using CI was confirmed.

Less-lethal hybrid ammunition wounds: a forensic assessment introducing bullet-skin-bone entity

Agencies all around the world now use less-lethal weapons with homogeneous missiles such as bean bag or rubber bullets. Contusions and sometimes significant morbidity have been reported. This study focuses on wounds caused by hybrid ammunition with the pathologists' flap-by-flap procedure. Twenty-four postmortem human subjects were used, and lesions caused on frontal, temporal, sternal, and left tibial regions by a 40-mm hybrid ammunition (33 g weight) were evaluated on various distance range. The 50% risk of fractures occurred at 79.2 m/sec on the forehead, 72.9 m/sec on the temporal, 72.5 m/sec on the sternum, and 76.7 m/sec on the tibia. Skin lesions were not predictors of bone fracture. There was no correlation between soft and bone tissue observed lesions and impact velocity (correlated to distance range). Lesions observed with hybrid ammunition were the result of bullet-skin-bone entity as the interaction of the projectile on skin and bone tissues.

First clinical study of a new virus-inhibiting surgical glove

QUESTION UNDER STUDY

Prospective clinical study to evaluate the tolerance, ergonomics and glove barrier value (mechanical resistance to breach) of a new surgical glove sandwiching droplets of a disinfecting agent between two layers of a synthetic elastomer (G-VIR) able to inactivate viruses when breached.

METHODS

100 surgical procedures were performed by six surgeons wearing G-VIR on 100 patients included after informed consent. Procedures were classified into laparoscopic (n = 28) or open surgery (n = 72); open surgery being subdivided either into superficial (n = 33) and deep (n = 39) or into hernia (n = 32) and non hernia (n = 40). The ergonomics and tolerance of the glove were evaluated by the surgeons using a questionnaire. Patients were clinically evaluated daily during hospitalization and once between the 4th to 6th postoperative week. All used gloves underwent a water leak test to detect any breach.

RESULTS

834 G-VIR gloves were used, 456 by the first surgeon and 378 by the assistant surgeon, resulting in 195 exposures, lasting 288 operator-hours (OH). No adverse effect on patients and/or surgeons linked to G-VIR could be observed. Ergonomics of G-VIR has been evaluated as equivalent as standard double gloving, excepted for donning which was more difficult (P <0.05). The breach rate per glove (BRpG) amounted to 1.8%. According to breach rate per operator-hour (BRpOH), surgical procedures could be categorized in low (laparoscopy), middle (non hernia and hernia superficial) and high (hernia deep) risk procedures.

CONCLUSIONS

G-VIR gloving offers an excellent mechanical protection, is suitable for daily surgical practice and maybe recommended in high risk surgical procedures.

First clinical study of a new virus-inhibiting surgical glove

QUESTION UNDER STUDY

Prospective clinical study to evaluate the tolerance, ergonomics and glove barrier value (mechanical resistance to breach) of a new surgical glove sandwiching droplets of a disinfecting agent between two layers of a synthetic elastomer (G-VIR) able to inactivate viruses when breached.

METHODS

100 surgical procedures were performed by six surgeons wearing G-VIR on 100 patients included after informed consent. Procedures were classified into laparoscopic (n = 28) or open surgery (n = 72); open surgery being subdivided either into superficial (n = 33) and deep (n = 39) or into hernia (n = 32) and non hernia (n = 40). The ergonomics and tolerance of the glove were evaluated by the surgeons using a questionnaire. Patients were clinically evaluated daily during hospitalization and once between the 4th to 6th postoperative week. All used gloves underwent a water leak test to detect any breach.

RESULTS

834 G-VIR gloves were used, 456 by the first surgeon and 378 by the assistant surgeon, resulting in 195 exposures, lasting 288 operator-hours (OH). No adverse effect on patients and/or surgeons linked to G-VIR could be observed. Ergonomics of G-VIR has been evaluated as equivalent as standard double gloving, excepted for donning which was more difficult (P <0.05). The breach rate per glove (BRpG) amounted to 1.8%. According to breach rate per operator-hour (BRpOH), surgical procedures could be categorized in low (laparoscopy), middle (non hernia and hernia superficial) and high (hernia deep) risk procedures.

CONCLUSIONS

G-VIR gloving offers an excellent mechanical protection, is suitable for daily surgical practice and maybe recommended in high risk surgical procedures.

Anticipated detection of imminent surgeon-patient barrier breaches. A prospective randomized controlled trial using an indicator underglove system

The double gloving indicator underglove system (IUS) is based on a colored detection of the outer glove perforation. Our objective was to determine the IUS efficiency to detect outer glove perforations and to reduce the risks of blood and body fluids exposure, warning the surgeon before the breach of the surgeon-patient barrier (SPB). A series of 100 visceral surgical procedures were randomly assigned to either double (IUS) or single gloving. The noticed glove perforations (using the water test method) and the IUS efficiency were analyzed in 99 procedures. In 49 single-gloving procedures, 19 perforations were noticed: one was immediately perceived (perceived accidental exposure, PAE); 3 were discovered as the gloves were being removed, and 15 were undetected before the water test (unperceived prolonged contact, UPC). In 50 double-gloving procedures (IUS), 16 perforations were noticed, all of them involving only the outer glove: the IUS allowed immediate detection of 3 perforations without any blood exposure; 13 other perforations went undetected but without any UPC. In conjunction with the protective quality of double gloving, the IUS allows detection of significant breaches of the outer glove before the breach of the SPB.

[Laparoscopic Janeway gastrostomy: an advantageous solution for self-sufficient enteral feeding]

INTRODUCTION

Laparoscopic gastrostomy according to Janeway (LGJ) is an alternative to percutaneous gastrostomy techniques.

METHODS

A series of 10 LGJ is reported. The laparoscopic technique involves an isoperistaltic tube of 6-7 cm of length and 10-12 mm of diameter is created by 2 applications of linear stapling and cutting device. The tube is led out, opened and fixed to the fascial and cutaneous planes and a Foley catheter is inserted.

RESULTS

Mean operation time was 35 minutes. There was no complication. The LGJ was indicated in 9 patients with tumour of the pharynx and 1 patient with encephalopathy.

CONCLUSION

The main drawback of the LGJ is the need of general anaesthesia. The main advantage is the creation by minimal invasive surgery of a permanent gastrostomy equipped with a removable catheter easily changeable by non specialized health professionals, and even by the patient himself.

Ballistic study of the SAPL GC27 gun: is it really "nonlethal"?

To evaluate the potential dangers of the "nonlethal" 12-gauge single-shot handgun SAPL GC27 with Fun-Tir (FT) and mini-Gomm-Cogne (mGC) ammunition, a ballistic study was performed with both types of ammunition. Nine unembalmed human corpses covered with a cloth sheet were shot through the right and left pectoral regions. With the mGC ammunition, rib fractures were observed when the firing range was less than 2 meters, skin perforation when the range was less than 1.5 meters, with lung injuries at less than 0.2 meter; the heart and the aorta were lacerated at contact range (0 meter). No skin perforation was observed with the FT ammunition, but rib fractures were observed when it was fired at up to 2 meters. Our study shows that the mGC ammunition, shot by the CG27 firearm, can be lethal at contact range and that pellets penetrate the skin at ranges of less than 1 meter. These results led us to conclude that this weapon is too dangerous to be marketed as a "nonlethal" weapon. The term "reduced wounding power weapon" is preferable.

Thoracotomie transverse de réanimation

The technique of resuscitative transverse thoracotomy is for use in case of circulatory arrest in the trauma patient. This technique, performed after orotracheal intubation, is initiated by a 5th intercostal space thoracostomy in each mid-axillary line. If the circulatory arrest is not caused by a tension pneumothorax, bilateral thoracotomies in the 5th intercostal spaces with transverse transsection of the sternum is performed. Middle vertical incision of the pericardium allows the evacuation of a cardiac tamponade. This wide surgical access has proved simple to perform, even by non experienced operators. It allows digital control of a heart wound, cross-clamping of the thoracic descending aorta or of pulmonary hilum, rapid perfusion of warm fluids through the right auricle and the performance of bimanual internal cardiac massage.

Review and evaluation of anatomy sites on the Internet (updated 1999)

In a preceding study, we had reviewed and evaluated the anatomy sites available on the Internet. The evolution of the available sites, the disappearance of certain sites and the appearance of new sites led us to update this list. In addition, the German-speaking sites were included in the study, which previously included only the Anglophone and French-speaking sites. Forty-eight sites were indexed and their addresses are available on the site of the Laboratory of Anatomy of the Faculty of Medicine Lyon-Nord (http://rockefeller.univ-lyon1.fr/Anatomie-Lyon- Nord). Compared to the scores allotted in 1998, we noted in 1999 a significant increase (p = 0.03) in the total score (12.13 +/- 2.98 vs. 11.23 +/- 2.28/20), which shows that the quality of the anatomic sites available on the Internet has improved.

Rat multiple organ blocks: microsurgical technique of removal for ex vivo aerobic organ preservation using a fluorocarbon emulsion

A multiple organ block (MOB) is composed of en bloc removed organs (heart, lungs, liver, pancreas, kidneys, and bowel), connected by the vascular system, of which blood circulation is maintained by the heart and oxygenation by the lungs under artificial ventilation. The aim of this study is the description of a surgical technique of MOB removal in the rat. Ninety-five MOBs were removed from Wistar rats. The rats were anesthetized, a tracheotomy was performed, and the cannula was connected to a pressure-regulated respirator. A colectomy was performed. Ureters, vena cava inferior, aorta, and bile duct were cannulated using an operative microscope. The vessels that joined the MOB to the carcass were tied or coagulated to make removal of the MOBs possible. Once removed, the MOBs were placed in a vaseline oil bath at 37 degrees C and the aorta and vena cava were connected to an accessory vascular circuit to stabilize arterious pressure. Success rate (ex vivo survival of more than 10 min) after the 30th attempt was 90% and after the 60th attempt was 95% (global success rate 82%). Ex vivo survival of MOBs at 37 degrees C ranged from 1 to 450 min. Rat MOBs allows us to study the normothermic preservation of all the organs susceptible of being transplanted in one single series of experiments. We showed that removal of rat MOBs is feasible. This microsurgical technique is codified. Rat MOBs are suitable if perfusion liquids are difficult to obtain or if a great number of experiments are required. As MOBs are composed of synergically functioning organs in the absence of striated muscle, bone, and nervous system, they also could be useful for physiologic and pharmacologic studies.

French mirror site of the NPAC visible human viewer: first year evaluation

The NPAC visible human viewer (NPAC VHV), graphical interface written in JAVA, freely accessible by the Web, allows the display of anatomic cross-sections of the Visible Human Project developed by the National Library of Medicine. In April 1997, the Medical Media Library of Lyons undertook the construction of a French-language mirror site of the NPAC VHV. The aim of this work is to evaluate first year utilisation of this site. From May 1st, 1997 to April 30th, 1998, the mirror site was consulted 34,752 times. In 45.14% of cases, the request came from France, in 4.42% of cases from Belgium, in 3.98% from Canada and in 2.12% from Switzerland. Other connections came either from a country responsible for fewer than 1% of connections or from unidentified computers. Data analysis showed a peak of connections between 15:00 and 17:00, and an increased number of connections from September to March 1998. The NPAC VHV is housed in 5 sites in the world. It is a software very simple to use. As the figures have no legends, it is more appropriate for group teaching than for self-teaching.

Prospecting and evaluation of the anatomy sites on the Internet

The Internet undoubtedly has an important part to play in medical teaching, generally speaking, and particularly in anatomy. We therefore undertook to survey, list, explore and study the various sites written in French or English devoted to anatomy on the Internet in order to evaluate them. Sites were identified from their URL address, by search engine or by hypertext links found in already listed sites. Useless and non-relevant sites were excluded. Fifty-two sites were selected and evaluated as to their navigability, illustrations, text and general presentation. Addresses of theses sites are available on a web page (http:/(/)www.rockefeller.univ-lyon1.fr/Anato mie-Lyon-Nord; section liens, section Galerie Virtuelle). This directory could be a very useful working tool for the use of teachers and students. It will be regularly updated.

[Appendectomy: evaluation of medical record maintenance in a series of 200 cases]

To improve the management of appendicular syndromes, two hundred files of patients undergoing appendectomy in an emergency surgery department between January 1993 and August 1994 were submitted to a retrospective and descriptive study with evaluation of the medical file content. To evaluate clinical and investigations data collecting, a histopathological review protocol was elaborated to obtain an objective and reliable criterion of the degree of inflammation of the appendix. This review was possible only for 197 files that were included. Data collecting rates are inferior than expected rates, particularly for the association of temperature, abdominal defence and white blood cells count that was found in only 159 files (80.7%). Data were less collected for women, patients operated by celioscopy and when histopathologic review concluded to absence of acute inflammation. Rate of acute appendicitis was 73.6% (145/197). Appendectomies without acute inflammation were higher for women (34.6% = 37/107) than for men (16.7% = 15/90) and for patients who underwent celioscopic appendectomy (42.9% = 33/77) than for patients who underwent Mac Burney appendectomy (16% = 19/119). These results highlight the need to improve competition of medical files with better collection of clinical data, which could lead to improve care quality and management of operated appendicular syndromes, first step to a reduction of the number of appendectomies. A global assessment of file completion could be proposed on the basis of clinical audit.

Gastrocolic vein. Definition and report of two cases of avulsion

The gastrocolic v. or Henle's gastrocolic trunk was described in 1868 [9]. We suggest defining this vein as the confluence of the right gastroepiploic and right upper colic vv. We report two original cases of avulsion of the gastrocolic v. occurring during a blunt abdominal trauma. The aim of this paper is a description, based on the literature, of the anatomy of the gastrocolic v. in order to precise the lesional mechanism. The gastrocolic v. is present in 70% of individuals. It is short (less than 25 mm) but of major calibre (3 to 10 mm). The gastrocolic v. is situated close beneath the root of the transverse mesocolon, and travels along the anterior surface of the head of the pancreas. Anatomic variations are detailed and a meta-analysis of interpretable studies was made. Both the supra- and infra-mesocolic surgical approaches are described. The radiologic and surgical importance of the gastrocolic v. is discussed. The lesional mechanism in both our cases of injury of the gastrocolic v. is explained.

[Cryosurgery of liver neoplasms]

Cryosurgery is the in situ destruction of tissue using subzero temperatures. Its use for the treatment of some unresectable liver tumors has been clearly established as a therapeutic option. Experimental studies have demonstrated the feasibility of freezing of large liver volumes without any major metabolic and hemorrhagic complications. Modern cryosurgery has received substantial impetus from the development of automated cryosurgical apparatuses using liquid nitrogen. Intraoperative ultrasound has enhanced the process by enabling visualization of tissue freezing and ensuring precise and optimal treatment of the tumor. Clinical reports of cryosurgery for liver primary tumors and metastases have confirmed the safety of the procedure. Major complications include myoglobinuria, coagulopathy and pleural effusions. The benefit of cryosurgery is that it broadens the number of patients that can be brought to surgery and can potentially become disease-free.

[Diaphragm rupture in closed trauma]

Ruptures of the diaphram occur in approximately 2% of cases of severe thoraco-abdominal trauma. They are present on the left in 80% of cases. The rupture is cupolar, sagittal or transversal, with peripheral desinsertion (the last always observed on the right), or paravertebral and retropericardiac posterior tears. Movement of the abdominal viscera toward the thorax can be progressive, with signs appearing only after 3 or 4 days or more. Any attempt to evacuate an intrathoracic effusion should be made carefully. In half the cases in polytraumatic patients, the lesion is confirmed by clinical suspicion or by appropriate surgical exploration. The first emergency step is repair. In cases of recent occurrence and for reasons of abdominal safety, coeliotomy is preferred. Mortality ranges from 20 to 30% and depends on the polytraumatic state but also on heart and respiratory failure and on infectious complications.

Aerobic preservation of organs using a new perflubron/lecithin emulsion stabilized by molecular dowels

The purpose of the study reported here was to explore a new strategy for the aerobic preservation of transplants using stable concentrated fluorocarbon emulsions as an oxygen delivery system. Fluorocarbons (FCs) are synthetic molecules, chemically and biologically inert, with a high oxygen-dissolving capacity. As they do not mix with water, it is necessary to emulsify them for intra-vascular use. Perfluorooctyl bromide (or perflubron) can be emulsifled with egg-yolk phospholipid (EYP), a nontoxic emulsifiant. The recent adjunction of amphiphilic fluorocarbon-hydrocarbon diblock molecules allows the obtaining of stable emulsions. By contrast with hemoglobin, fluorocarbons release oxygen following Henry's linear law rather than Barcroft's sigmoid curve. Release of oxygen by the FCs is only slightly influenced by temperature, which is an advantage for the preservation of organs. We tested a new 90% w/v fluorocarbon stem emulsion (perflubron/EYL/F6H10) diluted to 36% w/v with a hydroelectrolytic solution containing albumin, on four multiple organ blocks (MOBs; heart-lungs, liver, pancreas, kidneys, small intestine) of rats (EMOBs). Five control MOBs were perfused with a 50% v/v mixture of rat-blood and Krebs solution (KBMOBs). The lungs were ventilated with a FiO2 = 100%. In all cases the survival of the MOBs was greater than 210 min, with stable hemodynamics and preserved hydroelectrolytic and acid-base balances. The levels of lactate, amylase, and CK of the EMOBs were inferior (P < 0.05) to those of the KBMOBs between the first and the second hour. The diuresis of the EMOBs was higher (P < 0.05) than that of the KBMOBs (5.65 +/- 1.76 vs 1.21 +/- 0.28 mg/min). The production of bile, and the AST and ALT levels, were not significantly different. The PaO2 of the EMOBs was higher (P < 0.01) than for the KBMOBs. In normothermy, the maintenance of an aerobic metabolism using the FC emulsion caused less damage to the organs. Aerobic preservation of organs using FC emulsions therefore appears to be an attractive alternative to the presently used cold ischemia.

Hepatic cryosurgery precision: evaluation of ultrasonography, thermometry, and impedancemetry in a pig model

One of the main problems of the use of liver cryosurgery is to be sure that a defined hepatic volume has been completely destroyed. We undertook an experimental pig study to determine histopathological evolution of cryolesions, to evaluate the value of intraoperative sonography, thermometry, and impedancemetry to monitor necrosis and to evaluate clinical and biological repercussions of hepatic cryosurgery. Forty-eight cryolesions were obtained by freezing each liver lobe of 12 experimental pigs during a 5-min contact with a flat cryoprobe cooled with liquid nitrogen. Cryolesions and the surrounding liver were monitored during cryosurgery by six thermocouple electrodes, five impedance electrodes, and intraoperative sonography. Animals were sacrificed immediately, 6 hr and between day 1 and day 32 after the procedure. Cryolesions were excised, and a full size pathological study was carried out. No morbidity or mortality was observed. At the end of the freezing time, cryolesions were hemispheric in shape, and their radius measured by sonography was 17.7 +/- 1.2 mm (mean +/- SD). Microscopic study showed sequential tissue alterations with edema, ischemic necrosis, tissue slough, and granulation. Cryolesions were sharply delineated from the normal liver tissue. The radius of necrosis at days 2 and 3 was 17 +/- 0.3 mm (mean +/- SD). It showed good correlation with the cryolesion size measured by intraoperative sonography. The temperature threshold to obtain complete normal liver necrosis was -15 degrees C. We found impedancemetry too difficult to use and not precise enough to monitor cryonecrosis. We conclude that intraoperative sonography and thermometry are useful means to monitor the extent of cryonecrosis during liver cryosurgery.

Normothermic preservation of "multiple organ blocks" with a new perfluorooctyl bromide emulsion

To evaluate the efficiency of fluorocarbon emulsions as oxygenating media for the normothermic preservation of organs (multiple organ blocks, MOB), a new perfluorooctyl bromide (perflubron) emulsion was compared with a mixture of modified Krebs solution and blood. The fluorocarbon emulsion used (90% w/v of fluorocarbon) contained a low amount of egg yolk phospholipid (EYP, 2% w/v) and was stabilized by a mixed fluorocarbon-hydrocarbon amphiphile C6F13C10H21 (F6H10). Blood of 4 rat MOBs was replaced with a 36% w/v fluorocarbon emulsion which has been complemented with albumin and electrolytes (EMOBs). 5 MOBs were perfused with a mixture of blood and albumin-containing Krebs solution (KBMOBs). Lactate, amylase and creatine kinase were lower (p < 0.05) at 60 and 120 min in EMOBs than in KBMOBs,

Intraportal injection of monoclonal antibody in nude mice bearing hepatic metastases

Using a model for hepatic human colorectal carcinoma metastases in athymic mice, we compared the selective [intraportal (ip)] and systemic [intravenous (iv)] injection of radiolabeled monoclonal antibody (mAb) strongly reactive against the cell line. Percent injected dose of radiolabeled antibody per gram (%id/g) of tumor or normal tissues was measured at selected time points (up to 5 days postinjection) within 3 dose levels: 0.1, 1.0, and 2.0 micrograms (micrograms). At each dose level, 3-9 animals were studied in each of 3 groups: animals receiving ip injection (group HT-29-15 ip), those receiving intravenous injection (group HT-29-15 iv), and those receiving isotype-matched control antibody via the intraportal route (group BL-3 ip). Significantly greater (P < 0.005) %id/g in tumor was seen in group HT-29-15 ip at all time points and dose levels compared to those in groups HT-29-15 iv or BL-3 ip. However, immediately after injection of mAb, there was no difference in tumor %id/g between groups HT-29-15 ip and HT-29-15 iv at the highest dose level. There was no increase in %id/g of mAb in normal liver and blood after ip injection compared to iv injection beyond day 1. Therefore ip injection resulted in higher tumor to liver and tumor to blood ratios compared to iv (P < 0.005). We conclude that delivery of mAb to hepatic metastases can be enhanced by selective injection; this has important implications in the design of future clinical trials utilizing radiolabeled mAb in the diagnosis and treatment of hepatic metastases.