He aha ka maʻi ʻo Aortoiliac Occlusive? Ke ʻike nei ʻoe i ka emi ʻana o ke kahe koko i kou mau wāwae? E kamaʻilio kākou e pili ana i kēia!

Loaʻa iā ʻoe kekahi manawa ka ʻeha o kou wāwae ke hele ʻoe? Ke emi nei ka ʻeha ma hope o ke kū ʻana no kekahi manawa? A i ʻole ke manaʻo nei ʻoe i ka mae a i ʻole ke anu i kou mau wāwae? He mau hōʻailona paha kēia o kahi mea koʻikoʻi. I kēia lā e kamaʻilio mākou e pili ana i kahi maʻi i kapa ʻia ʻo 'Aortoiliac Occlusive Disease', nona kahi inoa paʻakikī, akā hiki ke hoʻopilikia i nā poʻe he nui. Mai hopohopo, e wehewehe maʻalahi kākou i kēia.

He aha ka maʻi ʻo Aortoiliac Occlusive?

I ka ʻōlelo maʻalahi, he paʻa kēia i loko o ke kīʻaha koko nui e hoʻolako ana i ke koko i ka ʻaoʻao haʻahaʻa o ko mākou kino. No loko kēia ʻano o kahi hui nui o nā maʻi i kapa ʻia ʻo 'Peripheral Artery Disease (PAD),' ʻo ia hoʻi nā kīʻaha koko e hoʻolako ana i ke koko i nā lālā.

Hoʻopilikia nui kēia maʻi i ka ʻaoʻao haʻahaʻa o ka `(Aorta)`, ke kīʻaha koko nui loa o ko kākou kino, a me nā kīʻaha koko i kapa ʻia ʻo `(Iliac arteries)`. ʻO `(Aorta)` ke kīʻaha koko nui e lawe i ke koko mai ka puʻuwai ma o ka umauma a i ka ʻōpū. ʻO `(Iliac arteries)` nā lālā nui ʻelua o kēia `(Aorta)` e māhele ana i ʻelua kokoke i ka ʻōpū a lawe i ke koko i nā wāwae.

I kēia manawa, ʻo ka mea e hana ʻia ana i kēia maʻi , ʻo ia ka mea i kapa ʻia ʻo `(Plaque)` e kūkulu ʻia ana i loko o kēia mau kīʻaha koko. ʻO `(Plaque)` kahi mea pipili i hana ʻia me nā mea e like me ka ʻaila a me ka cholesterol. E noʻonoʻo, he mea kēia e like me ka popo a me ka lepo e kūkulu ana i loko o kahi paipu wai i loko o ko mākou hale i ka hala ʻana o ka manawa.

ʻElua kumu e weliweli ai kēia `(Plaque)`:

• Hoʻēmi i ka hakahaka i loko o nā kīʻaha koko: I ka hōʻiliʻili ʻana o kēia `(Plaque)`, lilo ka hakahaka i loko o nā kīʻaha koko i mea liʻiliʻi. A laila ua ālai ʻia ke kahe o ke koko, e like me ke kaʻa paʻa.
• Hiki ke hana i kahi `(Embolus)`: I kekahi manawa hiki i kahi ʻāpana o kēia `(Plaque)` ke haki a hele pū me ke koko. ʻO kahi ʻāpana e haki ana e like me kēia ua kapa ʻia ʻo `(Embolus).` Inā paʻa kēia `(Embolus)` i kahi o loko o kahi kīʻaha koko liʻiliʻi, e pau loa ke kahe ʻana o ke koko mai laila mai.

Pehea e pili ai kēia i ko mākou kino?

ʻO ka maʻi ʻo Aortoiliac Occlusive kahi kūlana i ālai ʻia ai ke kahe koko ma nā aʻa Aorta a me Iliac. Hoʻoulu kēia i nā pilikia like ʻole no ka mea ʻaʻole hiki ke koko oxygenated i nā ʻiʻo o ko mākou kino i ke ala kūpono. No ka hoʻomaopopo ʻana i kēia, pono ʻoe e ʻike iki e pili ana i kēia mau kīʻaha koko.

Ua like ko kākou `(Aorta)` me ke alanui nui ma ke kūlanakauhale. Mai kēia alanui nui mai, lawe nā alanui ʻaoʻao he nui i ke koko i nā ʻāpana like ʻole o ke kino. No ka laʻana, ʻo nā `(Renal arteries)`, ka mea e hoʻolako ana i ke koko i ko kākou mau puʻupaʻa, ua māhele ʻia mai ka `(Aorta).` ʻO kēia māhele ka palena kiʻekiʻe kahi e hoʻomaka ai ka `(Aortoiliac Occlusive Disease)`. Ua kapa nā kauka i ka ʻāpana o ka `(Aorta)` ma lalo o kēia mau `(Renal arteries)`, a hiki i ka piko, ʻo `(Infrarenal aorta)`.

I kēia manawa, ma ke kumu o ke poʻo, ua māhele ʻia kēia ʻAorta i ʻelua , e like me ka ʻaoʻao Y i luna . ʻO kēia nā kīʻaha koko ʻelua i kapa ʻia ʻo ka ʻākau a me ka hema ʻo ia hoʻi ka ʻaoʻao iliac maʻamau. Hoʻokaʻawale hou kēia mau lālā a hoʻolako i ke koko i nā ʻāpana o ko mākou kino:

• Wahi puʻupuʻu
• Nā wāwae a me nā wāwae
• ʻĀpana ʻūhā
• Nā ʻāpana o ka ʻōnaehana hānau kāne a me ka wahine
• Nā kino o ka lua pelvic (e.g., ʻōpū mimi, akepaʻa)

ʻO ke koʻikoʻi o ka maʻi e pili ana i ka ʻāpana o kēia 'Y' i ālai ʻia a me ke ʻano o kona ālai ʻia ʻana. I kekahi manawa, inā he wahi liʻiliʻi wale nō i ālai ʻia, ʻaʻohe paha he mau hōʻailona nui. ʻO kēia no ka mea hiki i ke koko ke hele i kekahi ʻano ma o nā aʻa liʻiliʻi ʻē aʻe. Akā inā ua ālai nui ʻia, ʻoi aku ka koʻikoʻi o nā hōʻailona a ʻoi aku ka kiʻekiʻe o ka hiki ke loaʻa nā pilikia.

ʻO wai ka mea i loaʻa pinepine i kēia maʻi?

Ua manaʻo ʻia ua hoʻopilikia kēia maʻi ma mua o 6 miliona mau kānaka ma luna o 40 mau makahiki ma ʻAmelika Hui Pū ʻIa wale nō. Piʻi ka pilikia o ka loaʻa ʻana me ka makahiki. No ka laʻana, ma kahi o 5% o ka poʻe i ko lākou mau makahiki 50 i loaʻa iā ia, akā ʻoi aku ma mua o 20% o ka poʻe i ko lākou mau makahiki 80 i loaʻa paha iā ia. Eia kekahi, ʻoi aku ka maʻamau o kēia ʻano i nā kāne a me nā poʻe ʻeleʻele.

Hiki paha i kēia ke hoʻoweliweli i ke ola?

ʻAe, inā ʻaʻole mālama pono ʻia, hiki i ka maʻi ʻo Aortoiliac Occlusive ke alakaʻi i nā pilikia koʻikoʻi, i kekahi manawa e hoʻoweliweli ana i ke ola. Eia nā mea nui e hiki ke hana:

• ʻOki ʻia: ʻO ke ʻoki ʻana a me ka wehe ʻana i kahi ʻāpana o ke kino, e like me ka wāwae. Hana ʻia kēia no ka mea e make ana nā ʻiʻo ke ʻoki ʻia ke kahe koko.
• `(Hoʻouka puʻuwai)` (Hoʻouka puʻuwai): He hoʻouka puʻuwai.
• `(Ka hāʻule ʻana o ka puʻuwai)` (Ka hāʻule ʻana o ka puʻuwai): Ka hāʻule ʻana o ka puʻuwai.
• ʻO ke Gangrene (Gangrene): Ka make ʻana a me ka palaho ʻana o nā ʻiʻo.

No laila, he mea nui loa ia e hoʻolohe i kēia mau hōʻailona.

He aha nā hōʻailona?

ʻAʻole paha i loaʻa i kekahi poʻe kekahi mau hōʻailona. Eia nō naʻe, inā loaʻa iā lākou nā hōʻailona, ​​​​​​hiki iā lākou ke komo pū me:

• ʻO ka hana ʻino o ka erectile (ED): ʻO ka hiki ʻole i nā kāne ke hoʻokō a mālama paha i kahi erection i ka wā o ka moekolohe. Hiki ke pili pū kēia me kēia maʻi.
• `(Intermittent claudication)` (Intermittent claudication): He hōʻailona nui kēia i ʻike ʻia e ka poʻe he nui. I ka wā e hoʻoikaika kino ai, no ka laʻana, i ka wā e hele ana, aia ka ʻeha, ka paʻa, a i ʻole ka ʻoʻoleʻa ma nā puʻupuʻu a i ʻole nā ​​​​wāwae. Hoʻomaha ia ma hope o kekahi manawa o ka hoʻomaha. E noʻonoʻo i ko mākou kauhale, i ka wā e hele ai ʻo ʻAnakala Somapala i ka hale kūʻai, ma hope o ka hele ʻana i kahi mamao pōkole, kū ʻo ia a ʻōlelo, "ʻAuē, koʻu wāwae!", a ma hope o kekahi manawa, hele hou ʻo ia. He kūlana like kēlā.
• ʻEha Hoʻomaha: ʻEha ma nā wāwae e hoʻāla iā ʻoe i ka pō. Hiki ke loaʻa kēia ʻeha ke piʻi aʻe kou mau wāwae, ʻoiai ke hoʻemi nei ka umekaumaha i ke kahe o ke koko i lalo o nā wāwae.
• ʻUlu: ʻO nā ʻeha ho'ōla ʻole ma ka ʻili, i ʻike ʻia he ʻulu, hiki ke ʻike ʻia ma nā wāwae a i ʻole nā ​​​​​​kapuaʻi o nā wāwae.

Inā loaʻa iā ʻoe kekahi o kēia mau hōʻailona, ​​​​pono ʻoe e ʻike i ke kauka. No ka mea, inā ʻike ʻoe i nā hōʻailona o ka 'Aortoiliac Occlusive Disease' i ka wā mua, ʻoi aku ka maʻalahi o ka mālama ʻana.

E nānā pū kāu kauka i nā pilikia me ke kahe koko ma nā wahi ʻē aʻe o kou kino, e like me nā aʻa carotid i kou ʻāʻī a i ʻole nā ​​aʻa coronary i kou puʻuwai. ʻO ka maʻamau, inā hōʻiliʻili ka plaque ma kekahi ʻāpana o kou kino, aia paha ia ma nā wahi ʻē aʻe.

Pilikia: Paʻa ʻana o ke Alanui Koʻikoʻi

Eia nō naʻe, i kekahi manawa, ke lilo ke ʻano i mea koʻikoʻi, hiki ke loaʻa kahi pilikia i kapa ʻia ʻo "Acute arterial occlusion" . ʻO ke ʻano kēia, ua nele kekahi ʻāpana o kou kino, ʻo ka hapa nui he wāwae a he wāwae paha, i ke koko momona i ka oxygen. He pilikia olakino kēia e pono ai ke kōkua koke ʻia e ke kauka! Ua kapa ʻia kēia ʻo 'six Ps' a he mau hōʻailona kona:

• ʻEha: He ʻeha nui a hiki ʻole ke hoʻomanawanui. ʻO kēia ka mea mua āu e manaʻo ai.
• Pallor: Lilo ka ʻili ma ka wāwae i hoʻopilikia ʻia i ke keʻokeʻo loa.
• Ka nele o ka pulse: Ua nāwaliwali loa ka pulse ma ia wahi, a ʻaʻole paha i ʻike iki ʻia.
• Poikilothermia (anu): Ke hoʻopā ʻia, ʻoi aku ke anu o kēlā wāwae ma mua o kekahi.
• Paresthesia (manoʻano): Manaʻo ia me he mea lā ua mano kou wāwae, me he mea lā e holo ana nā ʻanuʻu, a i ʻole e like me nā pine a me nā nila .
• Paralysis: ʻAʻole hiki ke hoʻopā ʻia a hoʻoneʻe ʻia paha ka lālā i hoʻopilikia ʻia.

Inā ʻike ʻoe i kekahi o kēia mau hōʻailona, ​​e kāhea koke i ka 911 a i ʻole e hele i ka keʻena pilikia o ka haukapila kokoke loa! He mea nui kēlā me kēia minuke. ʻO ka lōʻihi o ke ālai ʻia ʻana o ke kahe koko, ʻoi aku ka nui o ka hōʻino ʻia o nā ʻiʻo. I nā hihia koʻikoʻi, hiki ke ʻoki ʻia ke poʻo a make paha.

He aha nā kumu no kēia?

ʻO ke kumu nui o kēia ʻMaʻi ʻAortoiliac Occlusiveʻ he maʻi i kapa ʻia ʻo `(Atherosclerosis)` . I ka ʻōlelo maʻalahi, ʻo ia hoʻi, ʻo ka `(Plaque)` i ʻōlelo ʻia ma mua e hōʻiliʻili mālie ana i loko o nā kīʻaha koko o ke kino. I kēia maʻi, ua waiho ʻia kēlā `(Plaque)` ma ka ʻaoʻao haʻahaʻa o `(Aorta)` a me nā `(Iliac arteries)`.

Ma waho aʻe o kēlā, aia paha kekahi mau kumu ʻē aʻe i loaʻa pinepine ʻole:

• Inā ua loaʻa iā ʻoe ka lāʻau lapaʻau radiation ma ka ʻāpana pelvic.
• ʻO ka mumū ʻana o nā kīʻaha koko, kahi maʻi i kapa ʻia ʻo "Vasculitis".

He aha nā kumu pilikia?

ʻOiai hiki i kekahi ke loaʻa i ka atherosclerosis, hiki i kekahi ke loaʻa i kēia maʻi. Eia nō naʻe, hoʻonui kekahi mau mea i ka pilikia:

• Ka ʻelemakule: Piʻi ka pilikia me ka makahiki.
• Moʻolelo ʻohana: Inā loaʻa i kekahi o kou ʻohana ka maʻi Peripheral Artery (PAD), e haʻi i kāu kauka e pili ana i ia mea.
• Puhipaka: He kumu pilikia nui kēia! ʻO ka puhipaka kahi kumu pilikia nui no kēia maʻi, a me nā maʻi vascular ʻē aʻe. Inā he mea puhipaka ʻoe, he mea nui loa e ʻimi i ke kōkua e haʻalele.
• Kekahi mau kūlana olakino:
• ʻO ka maʻi diabetes
• Ke koko kiʻekiʻe
• ʻO ke kolesterol kiʻekiʻe
• ʻO ka ʻaʻai koko o Takayasu (he maʻi laha ʻole kēia e hoʻopilikia ai i nā kīʻaha koko)

Pehea e ʻike ai i ka maʻi?

Inā loaʻa iā ʻoe kekahi o kēia mau hōʻailona, ​​ʻo ka mea mua āu e hana ai, ʻo ia ke ʻike i ke kauka. E hana kāu kauka i kēia mau mea e ʻike ai i ke kūlana a i ʻole e kāpae i kekahi kumu ʻē aʻe:

1. Nīnau iā ʻoe i nā nīnau:

• He aha kou mau hōʻailona?
• Mai ka manawa hea mai kēia mau mea a puni?
• I ka manawa hea ʻoe e manaʻo nui ai i kēia?
• Ke emi nei anei ia ke hana ʻoe i kekahi mea?
• Ke ʻino aʻe nei nā hōʻailona?
• Aia kekahi o kou ʻohana i loaʻa i kēia ʻano maʻi?
• He aha nā maʻi ʻē aʻe āu e loaʻa nei?

2. Hana i kahi hoʻokolokolo kino: E nānā i kou olakino holoʻokoʻa.

3. Hana i kekahi mau hoʻokolohua:

• Kuhikuhi kuʻekuʻe wāwae-brachial (ABI): He hoʻāʻo maʻalahi kēia, ʻaʻohe ʻeha. Ana ʻia a hoʻohālikelike ʻia ke koko i loko o kou mau lima a me kou mau wāwae. Hāʻawi kēia i kahi manaʻo maʻamau o ke kahe maikaʻi ʻana o ke koko i kou mau wāwae a me kou mau wāwae.
• Nā hoʻāʻo koko: Hiki i kēia ke kōkua iā ʻoe e nānā i nā mea e like me ka cholesterol a me nā pae kō, a me kāu mau mea pilikia no ka maʻi puʻuwai a me nā kīʻaha koko, a me kou olakino holoʻokoʻa.
• `(Computed tomography angiogram (CTA))`: He `CT scan` kūikawā kēia. Hiki iā ia ke ʻike maopopo i nā mea e like me kahi `(plaque)` i loko o nā kīʻaha koko a pehea lākou i ālai ʻia ai.
• ʻO ke ultrasound vascular (i kapa ʻia hoʻi ʻo Doppler scan): Hoʻohana pū kēia i nā nalu ultrasound e nānā i ke ʻano o ke kahe ʻana o ke koko i loko o nā kīʻaha koko a e ʻike inā he mau mea e ālai ana.

He aha nā lāʻau lapaʻau?

Aia ka lāʻau lapaʻau i ke koʻikoʻi o kou kūlana. I kekahi manawa hiki i nā loli o ke ʻano o ka nohona a me nā lāʻau lapaʻau ke kōkua i ka kaohi ʻana i ke kūlana a hoʻolohi i ka holomua o ka maʻi. Hiki i kāu kauka ke ʻōlelo i kēia mau mea:

• Lāʻau antihypertensive .
• ʻO ka lāʻau antiplatelet, e like me ka aspirin a i ʻole clopidogrel, he lāʻau ia e hōʻemi ai i ka pilikia o nā ʻaʻa koko .
• Nā hoʻololi ʻana i ka meaʻai: Ma muli o ka ʻai olakino, e like me ka ʻai Mediterranean a i ʻole ka ʻai DASH, hiki ke kōkua i ka kaohi ʻana i nā mea pilikia e like me ka maʻi diabetes a me ka cholesterol.
• Hoʻoikaika Kino: ʻO ka hoʻoikaika kino mau e like me ke kuhikuhi a kāu kauka hiki ke hōʻemi i nā kumu pilikia he nui a hoʻomaikaʻi i ke kahe koko i kou mau wāwae.
• Nā lāʻau lapaʻau kūikawā (e.g., Cilostazol) no ka ʻeha o ka wāwae e kū mai ana i ka wā e hele ana ('Intermittent claudication').
• Nā lāʻau hoʻohaʻahaʻa kolesterol ('Statins').
• He mea pono ke haʻalele loa i ka puhipaka a me ka hoʻohana ʻana i nā huahana paka .

Inā ʻaʻole hiki i kēia mau mea ke kaohi i ka maʻi, pono paha ʻoe i nā mea e like me:

• ʻO ke ʻoki ʻana i ke alahaka: Hana ʻia kahi ala hou e kāpae i ke kīʻaha koko i paʻa. Ua like kēia me ke ʻano o ka bypass artery coronary. ʻOkoʻa paha kahi o ka paʻa a me kahi e hoʻomaka ai a pau ai ke bypass ma muli o kou kūlana olakino.
• `(Ka hoʻokomo ʻana i ka stent)`: Hoʻokomo ʻia kahi `(Stent)` liʻiliʻi e like me ka ʻupena i loko o ke kīʻaha koko i paʻa e hoʻonui iā ia. Hoʻomaikaʻi kēia i ke kahe ʻana o ke koko. Hiki i nā kauka ke hoʻohana i nā ʻano `(Endovascular)`, ʻo ia hoʻi ke hoʻokomo ʻana i kēia `(Stent)` ma o kahi lua liʻiliʻi me ka ʻole o ka hana ʻana i kahi ʻoki nui.

Loaʻa i kēlā me kēia lāʻau lapaʻau kona mau pono a me nā pōʻino, no laila ʻoi aku ka maikaʻi o ke kūkākūkā ʻana i kēia mau mea āpau me kāu kauka a hoʻoholo i ke koho lapaʻau kūpono loa iā ʻoe.

Hiki ke pale ʻia kēia maʻi?

ʻAʻole paha hiki ke pale loa ʻia, akā he nui nā mea hiki iā mākou ke hana e hōʻemi i ka pilikia:

• E haʻalele i ka puhipaka a me nā huahana paka āpau.
• E ʻai i ka meaʻai olakino no ka puʻuwai haʻahaʻa i ka momona momona, cholesterol, paʻakai, a me ke kō.
• E hoʻoikaika kino mau e like me ke kuhikuhi a kāu kauka.
• E kāohi i kou koko, ke kō koko, a me nā pae cholesterol.
• E lawe i ka lāʻau lapaʻau i kauoha ʻia e ke kauka i ka manawa kūpono.
• E hana i kahi hoʻokolohua lapaʻau ma ka liʻiliʻi i hoʻokahi manawa i ka makahiki.

Inā he mau kumu pilikia kou no kēia maʻi a i ʻole atherosclerosis, e kamaʻilio me kāu kauka. ʻO ka wikiwiki o kou hoʻomaka ʻana e kaohi i kāu mau kumu pilikia, ʻoi aku ka maikaʻi o kou kūlana e pale aku ai i nā pilikia koʻikoʻi ma hope.

He aha ka mea e hana ai inā loaʻa iaʻu kēia maʻi?

I mea e ʻike pono ai i kou kūlana, pono ʻoe e kamaʻilio me kāu kauka. ʻO nā lāʻau lapaʻau e like me ke "ʻoki ʻana o Bypass" a me ke "hoʻokomo ʻana o Stent" he kūleʻa pinepine a lōʻihi nā hopena. E haʻi aku kāu kauka iā ʻoe i nā mea hou aʻe e pili ana i ka mea e manaʻo ai mai kāu hoʻolālā lapaʻau.

Pehea wau e mālama ai iaʻu iho?

He mea nui e hahai pono i nā ʻōlelo a kāu kauka e pili ana i nā loli o ke ʻano o ka nohona a me nā lāʻau lapaʻau. He mea nui hoʻi e hana pū me kāu kauka i kāu mālama ʻana. ʻO ia hoʻi:

• E nīnau i kāu kauka no nā kikoʻī e pili ana i kou kūlana a e hoʻomaopopo pono iā ia.
• Inā he mea āu e maopopo ʻole ai, e nīnau i nā nīnau. Mai makaʻu, aia ke kauka ma laila e kōkua iā ʻoe.
• E ʻike i ka mea hiki iā ʻoe ke hana e pale aku i ka maʻi mai ka lilo ʻana i mea ʻino.
• E ʻike i nā hōʻailona a me nā mea e hana ai inā loaʻa.
• E makaʻala i nā koho lapaʻau.
• E nīnau i kāu kauka e pili ana i nā kumuwaiwai a me nā hui kākoʻo e hiki ke kōkua iā ʻoe. E kōkua kēia iā ʻoe e hālāwai me nā poʻe ʻē aʻe i ke kūlana like me ʻoe a kaʻana like i kāu mau ʻike.

Āhea wau e ʻike ai i ke kauka?

E hana i nā hoʻokolohua lapaʻau ma ka liʻiliʻi hoʻokahi manawa i ka makahiki. E hōʻoia e hele i nā manawa hoʻopaʻa a kāu kauka i hāʻawi ai iā ʻoe. E haʻi aku kāu kauka iā ʻoe i ka pinepine o kou hele ʻana mai a me nā hoʻokolohua āu e pono ai.

Eia kekahi, inā loaʻa iā ʻoe kekahi mau hōʻailona hou a inā paha e loli kāu mau hōʻailona e kū nei, e kāhea koke aku i kāu kauka .

E hoʻomanaʻo ma ke ʻano he hōʻuluʻulu manaʻo

ʻO ka maʻi ʻo Aortoiliac Occlusive kahi ʻano maʻi ʻaʻai peripheral. Hiki iā ia ke hoʻopilikia i kou ʻano ola a hiki ke alakaʻi i nā pilikia koʻikoʻi. Akā ʻo ka nūhou maikaʻi , hiki iā ʻoe ke hana i kekahi mea i kēlā me kēia lā e hōʻemi i kou pilikia a kāohi i ka holomua o ka maʻi. E kamaʻilio me kāu kauka e pili ana i ke ʻano o ka mālama ʻana i kou kūlana a me nā mea e manaʻo ai i ka wā e hiki mai ana. ʻAʻole ʻoe hoʻokahi, a mai makaʻu e noi i ke kōkua.

ʻO ka maʻi ʻokiʻoki o ka ʻōpū o ka ʻōpū, ka maʻi ʻaʻai peripheral, ka PAD, ka paʻa ʻana o ke kīʻaha koko, ka ʻeha o ka wāwae, ka Atherosclerosis, ka plaque, ka embolus, ka intermittent claudication, ka stent, ke ʻoki ʻana o ka bypass