伊澤 祥光

BACKGROUND Inferior vena cava (IVC) injury is a potentially fatal injury with a high mortality rate of 34-70%. In cases in which the patient's condition is stable, diagnosis by computed tomography (CT) is the criterion standard. Findings on CT include retroperitoneal hematoma around the IVC, extravasation of contrast medium, and abnormal morphology of the IVC. We report a case of an IVC injury that could not be diagnosed by preoperative CT examination and could not be immediately detected during laparotomy. CASE REPORT A 73-year-old woman had stabbed herself in the neck and abdomen at home using a knife. When she arrived at our hospital, we found a stab wound several centimeters long on her abdomen and a cut approximately 15 cm long on her neck. We activated the massive transfusion protocol because she was in a condition of hemorrhagic shock. After blood transfusion and blood pressure stabilization, contrast-enhanced computed tomography (CT) revealed a small amount of fluid in the abdominal cavity. An otorhinolaryngologist performed successful drainage and hemostasis, and a laparotomy was performed. Gastric injury and mesentery injury of the transverse colon were identified and repaired with sutures. Subsequent search of the retroperitoneum revealed massive bleeding from an injury to the inferior vena cava (IVC). The IVC was repaired. Postoperative progress was good, and she was discharged from the hospital 65 days after her injuries. CONCLUSIONS We experienced a case of penetrating IVC injury, which is a rare trauma. Occult IVC injury may escape detection by preoperative CT examination or during laparotomy.

Introduction: Traumatic tension gastrothorax is a type of obstructive shock similar to tension pneumothorax. However, tension gastrothorax is not well known among emergency physicians, and no consensus has yet been reached on management during initial trauma care. We present a case of traumatic tension gastrothorax in which tube thoracostomy was performed based solely on clinical findings very similar to tension pneumothorax, followed by emergency laparotomy. Presentation of case: A 24-year-old male motorcyclist was brought to our emergency medical center after being struck by a motor vehicle. He was in respiratory failure and hypotensive shock with findings suggestive of pneumothorax. Although the physical findings were not fully in line with tension pneumothorax, we immediately performed finger thoracostomy. Subsequent radiography revealed left diaphragmatic rupture with hernia. After unsuccessful attempts to decompress the stomach with a nasogastric tube, immediate emergency laparotomy was performed. During the operation, the stomach, which had prolapsed through the ruptured diaphragm into the thoracic cavity, was manually returned to the abdominal cavity. The ruptured diaphragm was repaired with sutures. Discussion: Although distinguishing between tension pneumothorax and tension gastrothorax based on physical examination alone is difficult, tension gastrothorax requires careful attention to avoid intrapleural contamination from gastric injury. In addition, relying solely on stomach decompression with a nasogastric tube or delaying laparotomy could lead to cardiac arrest. Conclusion: When tension pneumothorax is suspected during initial trauma care, tension gastrothorax should also be considered as a differential diagnosis and treated with immediate diaphragmatic repair once identified.

症例は67歳男性。ダンプカーを運転中,他のトラックに追突し受傷した。来院時ショック状態であったが輸血により改善したため外傷パンスキャンCTを施行した。CTでは,腸間膜の血管外漏出像を認めたため緊急開腹止血術を行った。手術では腸間膜に複数の動脈性出血と横行結腸穿孔を認め,止血術と横行結腸部分切除を行った。腹部コンパートメント症候群の危険因子である大量輸血,腹腔内感染,肥満を認めたため,一期的な閉腹は行わずOpen Abdominal Management(OAM)を開始した。初回手術から8日後,4回目の手術を行い炎症による腸管浮腫で閉腹が困難であったことから,陰圧閉鎖療法を併用したMesh mediated fascial tractionを導入し,20日後に一次筋膜閉鎖を達成した。陰圧閉鎖療法を併用したMesh mediated fascial tractionは,重症腹部外傷などでOAMを行い閉腹困難となった症例に対する閉腹方法の選択肢となる術式と考えられた。(著者抄録)

症例は54歳男性。仕事中に鉄パイプの下敷きになり受傷した。CT検査で,鈍的外傷によると思われる左肺ヘルニア,左多発肋骨骨折,左血気胸,左肺挫傷,骨盤および左右大腿骨骨折,左腰椎横突起骨折と診断した。胸部損傷に対して左胸腔ドレーンを挿入して経過をみた。大腿骨骨折と骨盤輪骨折に対して固定術を行い,経過良好で入院50日目に転院した。肺ヘルニアは入院36日目のCT検査では還納されていたが,受傷から約7ヵ月後のCT検査で再発していた。その後の治療方針について呼吸器外科とも協議し,局所症状や呼吸器症状はないため,患者に説明のうえで経過をみる方針となり,受傷後約1年の現在まで無症状に経過している。外傷性肺ヘルニアは比較的まれな損傷形態で,病態によっては脱出と還納を繰り返す可能性から治療方針に苦慮することがある。いまだ定石はないがリスク・ベネフィットを考慮して方針を決める必要があると考えられる。(著者抄録)

BACKGROUND: In recent years, various home-use health devices have gained popularity. The abdominal roller is one of these. Spinal cord injury without radiological abnormality is known to occur even with relatively minor injuries, but there are few reports of such injuries caused by a roller. CASE PRESENTATION: Two cases of spinal cord injuries caused by a roller are reported. In both cases, injuries occurred during the standing rollout by a patient in an inebriated state, and the patients were rushed to an emergency department. CONCLUSION: Because the use of abdominal rollers may result in extremely serious disabilities, it is necessary to emphasize the appropriate use of such equipment.

Blast injuries caused by an improvised explosive device (IED) are becoming more common in civilian settings. However, physicians may not be familiar with the treatment and management of blast-injured victims. To the best of our knowledge, this is the first case report of a blast injury caused by an IED in Japan. A 64-year-old man was admitted to our hospital's emergency department after sustaining a blast injury. His vital signs were stable, but he had multiple small wounds with embedded foreign bodies that were consistent with injuries sustained by IED victims. The patient was treated for his injuries and was moved to another hospital on day 37. Knowledge about blast injuries caused by IEDs and management strategies for mass casualties are both necessary.

BACKGROUND Centipede envenomation is usually mild, but a review of the existing literature revealed a more serious course in a small proportion of patients. In fact, necrotizing soft-tissue infections have been reported following centipede stings in a small number of cases and require early diagnosis and treatment because of a high mortality rate. CASE REPORT A 78-year-old man was stung by a centipede on the left abdomen. Treatment with antimicrobial agents was started due to cellulitis, but extensive erythema developed from the left chest to the left buttock. Six days after being stung, he visited our hospital. Necrotizing soft-tissue infection was diagnosed and treated immediately with antibiotics and debridement on the left side of the abdomen and chest. Group A Streptococcus was detected in the fascia. The wound was left partially open and washed daily, resulting in gradual improvement of the wound condition. On hospitalization day 8, the open wound was able to be closed. Antimicrobial therapy was completed on hospitalization day 16. The patient showed good progress. CONCLUSIONS Centipede stings are not rare in tropical and subtropical regions, and most occurrences of centipede envenomation cause only local symptoms. However, we believe that even wounds caused by centipedes should be monitored, given the possibility of subsequent severe infection, as in the present case. In addition, the causative organisms identified in the present patient with necrotizing soft-tissue infection following a centipede sting were commensal bacteria of the skin. Future research is thus needed to clarify the relationship between these causative organisms and centipedes.

50歳代男性。トラックを運転中, 停車していたトラックに追突して受傷した。精査のComputed tomography (CT) にて両側外傷性気胸・骨盤骨折に加えて左総頸動脈の造影途絶を認めた。左内頸動脈および左外頸動脈は造影されていた。頭蓋内に梗塞所見はないため慎重に経過観察していたが, 来院14時間後に右片麻痺と意識レベルの低下が出現した。magnetic resonance imaging (MRI) で左中大脳動脈領域の脳梗塞を認めた。骨盤骨折の手術後から抗凝固療法を開始した。失語と麻痺は残存したが神経症状は増悪なく経過し, 約2カ月後に転院した。鈍的外傷による総頸動脈閉塞はまれな疾患であるが, 神経症状出現率・死亡率がともに高率である。治療として抗血小板薬の有用性が報告されているが, 多発外傷の患者においては出血増悪によるリスクも加味する必要があり, 治療には今後さらなる検討が必要と考えられた。

35歳、男性。約3mの屋根から墜落し、4×4×80(cm)のアルミ角材が右側腹部に刺入した。呼吸循環動態は安定していたが、創部から持続的な出血を認めた。角材が大きく術前にCT施行できず、やむを得ず単純撮影の情報のみで緊急手術とした。腹部正中切開で開腹したところ、腹壁貫通創と外側区域の肝損傷(日本外傷学会分類II型)を認めた。止血は得られていたので腹腔内の観察・洗浄と刺入部の縫合のみ行い腹部開放管理、翌日に止血を確認後閉腹、経過良好で第11日病日退院とした。杙創は高所墜落や転倒による臀部への体幹垂直方向の受傷が多く、体幹側方からは少数である。刺入物を抜去せず搬送されることが多く、その大きさや性状によりCT撮影が困難もしくは不可能な場合がある。体幹側方の場合はその可能性が高まる。手術には万全の体制で臨むとともに、平時より外傷手術のシミュレーションなどを活用して緊急開腹手術のトレーニングや研修を積む重要性を再認識した。(著者抄録)

骨髄路確保は重度患者に対する処置として重要だが、研修医が学習する機会は少ない。今回、当院救急科で研修した36人の研修医を対象にブタの胸骨に骨髄針を挿入するシミュレーションを行い、その前後にテストとアンケートを実施してその結果を評価した。シミュレーションでの骨髄路確保の成功率は100%だった。理解度テストの結果は、9.2±0.94(平均±標準偏差)から9.6±0.79に改善された(満点10、P=0.017)。骨髄針に関するアンケートの点数は7.4±2.9から14±1.3に増加した(満点15:P<0.0001)。特に自己効力感に関するスコアは1.8±0.91から4.1±0.64に増加した(満点5、P<0.0001)。このシミュレーションで骨髄路確保に関する知識・理解・自己効力感が向上した。本トレーニングにより、骨髄路確保がより良くできる可能性がある。(著者抄録)

BACKGROUND: Unnecessary whole-body computed tomography (CT) may lead to excess radiation exposure. Serum D-dimer levels have been reported to correlate with injury severity. We examined the predictive value of serum D-dimer level for identifying patients with isolated injury that can be diagnosed with selected-region CT rather than whole-body CT. METHODS: This single-center retrospective cohort study included patients with blunt trauma (2014-2017). We included patients whose serum D-dimer levels were measured before they underwent whole-body CT. "Isolated" injury was defined as injury with Abbreviated Injury Scale (AIS) score ≤ 5 to any of five regions of interest or with AIS score ≤ 1 to other regions, as revealed by a CT scan. A receiver operating characteristic curve (ROC) was drawn for D-dimer levels corresponding to isolated injury; the area under the ROC (AUROC) was evaluated. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for several candidate cut-off values for serum D-dimer levels. RESULTS: Isolated injury was detected in 212 patients. AUROC was 0.861 (95% confidence interval [CI]: 0.815-0.907) for isolated injury prediction. Serum D-dimer level ≤ 2.5 μg/mL was an optimal cutoff value for predicting isolated injury with high specificity (100.0%) and positive predictive value (100.0%). Approximately 30% of patients had serum D-dimer levels below this cutoff value. CONCLUSION: D-dimer level ≤ 2.5 μg/mL had high specificity and high positive predictive value in cases of isolated injury, which could be diagnosed with selected-region CT, reducing exposure to radiation associated with whole-body CT.

症例は患者が飼育中のアマゾン産淡水エイPotamotrygon leopoldiの水替え中に手背を刺されて来院したもので,刺傷後から疼痛が激しく,創部の洗浄と消毒に加え,海産エイ毒の解毒方法に準じて40℃の湯に創部を浸漬したところ,疼痛の軽減を図ることができた。その後,疼痛が数日の間は継続したが,広範な壊死を来すことはなく細菌感染などの併発もなく治癒した。エイ毒は複数の蛋白毒で構成され,疼痛・腫脹・壊死を来すほか,ショック症状・呼吸困難を来し,ときに死に至ることもある。一部の海産タンパク毒と同様に高温に弱く,患部を温水に浸漬することで症状を軽減できるといわれるが,種差・性差・成熟度による毒性・毒量を含めて不明な点が多い。本邦では淡水エイによる刺傷の報告が少なく,今回の症例のように後遺症を認めずに治癒する症例がある一方で,後遺症や手術を要した症例も報告されている。淡水エイの毒性については不確定なことが多く,症例および治療経験の蓄積が重要であると考えられた。(著者抄録)

Resuscitative endovascular balloon occlusion of the aorta (REBOA) increases proximal pressure, and simultaneously induces distal ischemia. We aimed to evaluate organ ischemia during partial REBOA (P-REBOA) with computed tomography (CT) perfusion in a swine model. The maximum balloon volume was recorded as total REBOA when the distal pulse pressure ceased. The animals (n = 4) were scanned at each 20% of the maximum balloon volume, and time-density curve (TDC) were analysed at the aorta, portal vein (PV), liver parenchyma, and superior mesenteric vein (SMV, indicating mesenteric perfusion). The area under the TDC (AUTDC), the time to peak (TTP), and four-dimensional volume-rendering images (4D-VR) were evaluated. The TDC of the both upper and lower aorta showed an increased peak and delayed TTP. The TDC of the PV, liver, and SMV showed a decreased peak and delayed TTP. The dynamic 4D-CT analysis suggested that organ perfusion changes according to balloon volume. The AUTDC at the PV, liver, and SMV decreased linearly with balloon inflation percentage to the maximum volume. 4D-VR demonstrated the delay of the washout in the aorta and retrograde flow at the inferior vena cava in the highly occluded status.

症例は40歳代男性で、仕事中、機械で削っていたアルミ塊(重量3kg)が弾き飛ばされ、右胸部にあたり受傷した。当院病着時、バイタルサインは比較的安定していたため胸腹部ダイナミックCTを施行したところ、日本外傷学会分類IIIbの肝損傷と、早期相での血管外漏出像を認めた。経カテーテル動脈塞栓術での加療の方針として、内側区域の肝動脈をn-butyl-2-cyanoacrylateで塞栓して止血が得られた。入院後、全身状態は安定していたが、入院4日目に経口摂取を開始したところ腹部症状が徐々に増悪し、それに伴ってビリルビン値の上昇を認めた。入院6日目に胆汁性腹膜炎を併発し、開腹ドレナージとendoscopic nasoBiliary drainage(ENBD)チューブを留置して手術終了した。術後、症状は消失し、全身状態は改善した。入院16日目のENBDチューブ造影では内側区域枝と外側区域枝の複数の肝内胆管の損傷が疑われた。引き続きドレナージを継続していたが、入院33日目に腹痛・発熱が再燃し、腹部造影CTで肝膿瘍を認めたため経皮的ドレナージを施行した。経皮的ドレナージにより感染はコントロールされたが、依然として胆汁漏は持続していた。持続する胆汁漏が存在し、広範囲肝壊死が感染を繰り返す可能性もあったことから、感染が改善した入院60日目に待機的に肝左葉切除術を施行した。その後の経過は良好で、入院82日目に退院となった。

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a viable resuscitation approach for a subdiaphragmatic injury that can regulate arterial blood flow. On the other hand, the evaluation of venous or portal venous blood flow during REBOA remains insufficient because invasive cannulation or exposure of the vessel may affect the blood flow, and Doppler echography is highly operator-dependent. However, phase contrast magnetic resonance imaging has enabled accurate evaluation and noninvasive measurement. This study aimed to investigate the change of venous and portal venous blood flow during REBOA in a porcine model. METHODS: Seven pigs were anesthetized, and a REBOA catheter was placed. The blood flows of the inferior vena cava (IVC), hepatic vein (HV), portal vein (PV), and superior vena cava (SVC) were measured using phase contrast magnetic resonance imaging, in both the balloon deflated (no-REBOA) and fully balloon inflated (REBOA) states. Mean arterial pressure (MAP), central venous pressure, cardiac index, and systemic vascular resistance index were measured. RESULTS: The blood flows of the suprahepatic, infrahepatic, and distal IVC, HV, and PV in the no-REBOA state were 1.40 ± 0.36 L·min, 0.94 ± 0.16 L·min, 0.50 ± 0.19 L·min, 0.060 ± 0.018 L·min, and 0.32 ± 0.091 L·min, respectively. The blood flow of each section in the REBOA condition was significantly decreased at 0.41 ± 0.078 (33% of baseline), 0.15 ± 0.13 (15%), 0.043 ± 0.034 (9%), 0.029 ± 0.017 (37%), and 0.070 ± 0.034 L·min (21%), respectively. The blood flow of the SVC increased significantly in the REBOA condition (1.4 ± 0.63 L·min vs. 0.53 ± 0.14 L·min [257%]). Mean arterial pressure, central venous pressure, cardiac index, and systemic vascular resistance index were significantly increased after REBOA inflation. CONCLUSION: Resuscitative endovascular balloon occlusion of the aorta decreased blood flows of the IVC, HV, and PV and increased blood flow of the SVC. This result could be explained by the collateral flow from the lower body to the SVC. A better understanding of the effect of REBOA on the venous and portal venous systems may help control liver injury.

BACKGROUND: The management of cardiac trauma requires rapid intervention in the emergency room, facilitated by a surgeon with prior experience to have good outcomes. Many surgeons have little experience in the requisite procedures. We report here 4 patients who suffered cardiac trauma, and all 4 patients survived with good neurologic outcomes. CASE PRESENTATIONS: Patient 1 suffered blunt cardiac trauma from a motor vehicle accident and presented in shock. Cardiac tamponade was diagnosed and a cardiac rupture repaired with staples through a median sternotomy after rapid transport to the operating room. Patient 2 suffered blunt cardiac trauma and presented in shock with cardiac tamponade. Operating room median sternotomy allowed extraction of pericardial clot with recovery of physiologic stability. Patient 3 presented with self-inflicted stab wounds to the chest and was unstable. She was brought to the operating room and thoracotomy allowed identification of a left ventricle wound which was repaired with a suture. Patient 4 presented in cardiac arrest with multiple self-inflicted stab wounds to the chest. Emergency room thoracotomy allowed repair of a right ventricle laceration with recovery of vital signs. CONCLUSIONS: The management of all 4 patients was according to the principles taught in the ATOM course. Three of the 4 surgeons had no prior experience with management of cardiac trauma and credited the good outcomes to taking the ATOM course. These are uncommon injuries and formal training in their management is beneficial to patients.

INTRODUCTION: Resuscitative endovascular balloon occlusion of the aorta (REBOA) increases proximal arterial pressure, but may also induce life-threatening distal ischemia. Partial REBOA (P-REBOA) is thought to mitigate distal ischemia during aortic occlusion. However, feasible indicators of the degree of P-REBOA remain inconsistent. We hypothesised percent balloon volume could be a substitute for pressure measurements of gradients during P- REBOA. This study aimed to compare balloon volume and arterial pressure gradient, and analysed with intra-balloon pressure and balloon shape. METHODS: Proximal (carotid) and distal (femoral) arterial pressures were recorded and a 7-Fr REBOA catheter was placed in four swine. Total REBOA was defined as a cessation of distal pulse pressure and maximum balloon volume was documented. The balloon volume was titrated by 20% increments of maximum capacity to adjust the degree of P-REBOA. The distal/proximal arterial pressure gradient and the intra-balloon pressures were also recorded. The changes in shape and the cross-sectional area of the balloon were evaluated with computed tomography (CT) images. RESULTS: The proximal mean arterial pressure (MAP) plateaued after 60% balloon volume; meanwhile, distal pulse pressure was still left. The balloon pressure was traced with proximal MAP before contact with aortic wall. The balloon shape changed unevenly from "cone" to "spindle" shape, although the balloon cross-sectional area of the mid-segment linearly increased. CONCLUSION: Monitoring distal pressure and titrating percent balloon volume is feasible to manage P-REBOA. In this experiment, 60% balloon volume was enough inflation to elevate central pressure allowing distal perfusion. The intra-balloon pressure was not reliable due to the strong influence of proximal MAP and uneven change of the balloon shape.

症例は94歳女性。右腹痛及び右腹部腫脹で当院を受診した。CT検査で腹腔内の右鼠径部周囲を狭窄起点とするclosedloopを形成する拡張小腸を認め、内ヘルニアと診断し鼠径部前方アプローチ法で緊急手術を行った。ヘルニア内容のない大腿ヘルニア嚢を認め、腹腔内には子宮円靱帯によって絞扼された壊死小腸を認めた。大腿ヘルニアを合併した子宮広間膜裂孔ヘルニアと診断し、子宮円靱帯を切離し壊死小腸を切除・吻合した後にMcVay法にて大腿ヘルニアを修復した。子宮広間膜裂孔ヘルニアはHuntらにより貫通形態でFenestra typeとPouch typeに分類され、Cilleyらにより裂孔の解剖学的部位でType1からType3に分類されている。大腿ヘルニアを合併した子宮広間膜裂孔ヘルニアの報告はなく、Type3の子宮広間膜裂孔ヘルニアは稀な病態であり、その診断には解剖学的分類の理解が必要である。(著者抄録)

ダメージコントロール戦略は全ての損傷の治療を行うのではなく、まず出血と汚染のコントロールに主眼を置き、のちに根治的治療を行う治療戦略であるが、小児においても原則は同様とされる。今回我々は6歳の男児で腹部鈍的外傷受傷後に心停止となり、ダメージコントロール手術を施行した症例を経験した。患児は病着前に自己心拍が再開し、複数回の手術を行い神経学的後遺症なく救命できた。小児患者においてもダメージコントロール戦略を念頭に適切に治療を行うことが救命のために重要である。(著者抄録)