背景與目的 二氧化碳是最常用來增加腹內壓力以提供腹腔鏡手術空間的氣體，但是在心肺功能不佳的病人, 潛藏著使心輸出量減少，及血中二氧化碳溶解量增高的危險。針對這種病人我們設計了一種新的腹腔鏡套管，可減少腹內壓，但仍可安全地操作腹腔鏡手術。
動物與方法 新的腹腔鏡套管有四個可彎曲的葉片，當它們固定在彎折的狀態時，讓套管有如長了四個小翅膀，可以卡在腹壁內面，再利用鋼絲把套管往上拉，便可提高腹壁，提供額外的空間給腹腔鏡操作。我們首先試驗使用這種新的套管進行手術所需之最低腹內壓是多少，結果發現隨著不同區域的器官，所需最低腹內壓也不同。由於腹腔鏡膽囊切除術是目前最盛行的腹腔鏡手術之一，我們用它來比較新式套管及傳統套管在腹腔鏡手術中使用的差別。我們總共使用6隻豬，分成兩組，一組 (C組) 3隻以傳統套管在15mmHg腹壓下，進行常見的腹腔鏡膽囊切除術；另一組 (N組) 3隻，以新式套管在5 mm Hg腹壓下，進行膽囊切除手術。
結果 在整體的手術時間上，N組明顯比較長，但真正進行組織分割的時間，兩組一樣。在這兩組動物的實驗手術過程中，都沒有手術併發症，出血量也很少。因灌二氧化碳而造成的血中二氧化碳溶解量增高量上，N組明顯地比C組低。

Background and purposes: Carbon dioxide is the common gas material to establish pneumoperitoneum to provide working space for laparoscopic surgeries, but possesses risks of reduced cardiac output and hypercarbia in cases with limited cardiopulmonary reserve. For such cases, we design a novel trocar to reduce the intrabdominal pressure, so as to perform the same operation safely.
Animals and Methods: The novel trocar has four flexible leaflets that can be fixed as “extended status” to hold the inner surface of abdominal wall. When the trocar was tracted upward with iron wires, the abdominal wall can be elevated. The lowest pressure of pneumoperitoneum with the usage of the novel trocar was tested first. We found the pressure was dependent on the target organ. Laparoscopic cholecystectomy was performed to compare the advantage of the novel trocar over the conventional trocar because it is one of the most commonly performed surgeries. Totally 6 pigs were used. They were divided into two groups: 3 pigs as the control group receiving operation with the conventional trocars (group C) under 15 mm Hg pneumoperitoneum, and another 3 with the novel trocar (group N) under 5 mm Hg pneumoperitoneum.
Results: The total operation time was significantly longer in group N but the precise dissection time was comparable with group C. No surgical complication was noted in both groups and the blood loss was minimal. The hypercarbia was of a much lesser degree in group N compared to that in group C.
Conclusions: Our preliminary data show that with the novel trocar, the laparoscopic cholecystectomy could be smoothly completed under a lesser pressure of 5 mm Hg CO2 pneumoperitoneum in pigs.

[Abstract] ……………………………………………………………………………… 1
[中文摘要] ……………………………………………………………………………… 3
[Introduction]
Laparoscopy and surgery ………………………………………………………… 4
Pneumoperitoneum during laparoscopy ………………………………………… 6
Physiologic effects of pneumoperitoneum …………………………………… 8
Backgrounds of the novel trocar ……………………………………………… 10
Why, when and how laparoscopic cholecystecotmy was performed ………… 11
[Materials and Methods]
The novel trocar …………………………………………………………………… 13
Pressures in laparoscopic operations ………………………………………… 13
Comparison between the novel trocar and conventional trocar ………… 14
[Results] ………………………………………………………………………………… 17
[Discussions] …………………………………………………………………………… 18
[Conclusion] …………………………………………………………………………… 21
[References] …………………………………………………………………………… 22
[Tables] ………………………………………………………………………………… 24
[Figures and Legends] ………………………………………………………………… 28

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