Carboxytherapy: effects on microcirculation and its use in the … · 2017-11-06 · the effects on microcirculation bed and lymphatic drainage are here analyzed to show how Carboxytherapy

114—ACTA/Casi clinici ACTA PHLEBOL 2007;8:000-000

Carboxytherapy: effects on microcirculation and its usein the treatment of severe lymphedema

A review

Carboxytherapy refers to the administration of CO2 for ther-apeutic purposes. It has been shown that, because of the inter-action between CO2 and regulating factors of tissue perfusion,Carboxytherapy acts on the microcirculation at the level ofmetarterioles, arterioles and precapillary shpincteres by increas-ing tissue flow velocity and consequently, by improving lym-phatic drainage. Analysis of literature data shows a wide rangeof today applications for this treatment involving either phle-bology or non-phlebology fields. Specifically, the positive effecton the increase of lymphatic drainage has more recently madeCarboxytherapy useful for treatment of lymphatic stasis. Basichemodynamic, histologyc and biochemical principles that explainthe effects on microcirculation bed and lymphatic drainage arehere analyzed to show how Carboxytherapy can be useful inthe treatment of diseases such as severe lymphedema.

KEY WORDS: Carboxytherapy - Microcirculation - Lymphedema.

Carboxytherapy refers to the administration ofCO2 for therapeutic purposes.1 Although this

treatment originated in France in 1932 and was thenintroduced in Italy in 1990 by Belotti and DeBernardi,2 it was only in 1995 that the term“Carboxytherapy” was coined by Luigi Parassoniduring the XVI National Meeting of EstheticalMedicine, promoted at Rome by the Italian Societyof Esthetical Medicine.3-13 Indeed, this therapy wasalso known as “carbon dioxide therapy” because ofthe CO2 molecular configuration including two oxy-gen and one hydrogen atoms.

The microcirculation

Hemodynamic essentials

The role of cardiovascular system is to provide oxy-gen, nutrients and hormones to, as well as remove car-bon dioxide and wasted from the cells and to ensure“body homeostasis” by keeping the concentration ofdissolved participles, the temperature, the volume andthe pH level largely constant. The circulatory systemcan be subdivided into a pulmonary circulation and asystemic circulation, the last providing to the perfusionfor all the tissues except for lungs and also called “bigcirculation” or “peripheral circulation”.5

Due to dissimilarities concerning development andfunction, blood vessels are differentiated in arterials,arterioles, metarterioles, capillaries,venules and veins.In the “microcirculation” arterial tree divides intomunerous arterioles which again divide into capillar-ies and sinusoids. Components of Microcirculation,that refers to the smallest blood vessels in the body, areshown in Figure 1.

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V. VARLARO 1, G. MANZO 1, F. MUGNAINI 1, C. BISACCI 1, P. FIORUCCI 1, P. DE RANGO 2, R. BISACCI 1

Vol. 8 - N. ACTA PHLEBOLOGICA 1

1Interuniversitary Center for the Educationand the Research on PhlebologyDepartment of Surgical Sciences

University of Perugia, Perugia, Italy2Department of Vascular and Endovascular Surgery

University of Perugia, Perugia, Italy

VARLARO CARBOXYTHERAPY

2 ACTA PHLEBOLOGICA Mese 2007

Arterial vessels supply high pressure blood flowfrom the heart to body tissues. The function of arteri-oles and metarterioles is to regulate blood flow throughcapillary bed and to ensure a “vis a tergo” that allowsflow in the microcirculation. The principal functionof capillaries is to permit the exchange of substances(water, electrolytes, nutrients, hormones) between tis-sues and blood. The venules collect blood from capil-lary bed and finally, the veins transport the blood backto heart and also serve as capacity vessels of large vol-ume.

A common characteristic for all the types of circu-latory vessels is the “distensible” property. In the arte-rial district, distensibility allows vessels to receive

high pressure, pulsatile blood flow from the heartpump and to deliver while buffering these pulsatileexcessive pressure and flow towards the small periph-eral vessels. The highest distensibility is a propertyof the venous systems. Due to the large expansibilitythe veins represent a temporary reservoir of large bloodvolumes which are stored but can be utilized, whennecessary, in whichever body district.5

The heart is filled with low pressure blood flowfrom the venous systems. By the contraction of theheart muscle, the blood is then driven rhythmically(at each systole) and at high pressure through arterieswhich, due to their elastic properties, represent a “pres-sure chamber”. The most important function of largearteries is to reduce the impedance (dynamic resis-tance to the oscillatory components of pulsatile flow)to left ventricular outflow. This is accomplished direct-ly by arterial expansion during systole and storage ofblood for run-off in diastole. The elastic retractionsof the arterial walls push and dampen the flow from thelarge arteries towards the microcirculation. Blood flowis subsequently collected into the low pressure sys-tem of the venules and veins.

Histology essentials

Elastic retraction is an essential property of arteri-al vessels in order to ensure a continuous blood flowin the microcirculation. Without this retraction, theblood could reach peripheral bed (microcirculation)exclusively during the systolic phase due to the propul-sive heart force. Properties and functions of arterials areexplained by the structure of the arterial wall.5

The wall of arterial vessels is quite thick and strongand is structured in a typical well distinct three-layerconfiguration that is common for all the arteries: an inti-mae layer (tunica intima) made up of endothelial cells,a medium layer (tunica media) mainly represented bytransverse-oriented smooth muscle fibro cells and anadventitial external layer (tunica adventitia) formedby bundles of fibroblastic cells and collagen fibresmostly oriented with longitudinal direction. An inter-nal elastic membrane is mostly present at the borderbetween tunica intima and media. The external elasticmembrane demarcates the border to the tunica adven-titia (Figure 2). According to the wall compositiontwo types of arteries, elastic (conductive arteries) andmuscular (distributive arteries), can be identified.Inelastic arteries, which include the largest arteries ofthe body, the borders between intima, media and adven-

ArteriolaMuscolo liscio

Sfinteriprecapillari

Metarteriole

Anastomosiartero-venosa(shunt)

Capillarecostituito daun singolo

stratodi endotelio

Venule

Figure 1.—Components of Microcirculation: arterioles, metarterioles,capillaries, precapillary sphincters, capillary shunt, venules.

Media

Avventizia

Endotelio

Elastica esterna

LumeElastica interna

Figure 2.—Three-layer structure of arterial wall (microscopic view).


CARBOXYTHERAPY VARLARO

titia are less distinct compared to muscular arteries,due to the presence of numerous fenestrated elasticlamellae in all three layers. In the medium layer up to70 lamina of elastin with large fenestration can befound. Close to the heart, elasticity of the arteries is ofgreat functional importance: during systole, the aortaand the elastic arteries dilate and then, during dias-tole, gradually return to their original size due to theirelastic properties. By this means, the pulsatile bloodflow is turned into a more steady flow, reducing bloodpressure requirements.

The most common type of arterial vessels is repre-sented by muscular arteries. In these, the medium lay-er is composed by variable strata of smooth musclefibro cells (“myofibroblast”), ranging from 3-4 in thesmallest arteries to 30-40 strata in the largest.

Arterioles and metarterioles are small muscular ves-sels (an endothelium surrounded by one or more lay-ers of smooth muscle cells) and represent a major sitefor regulating systemic vascular resistance in the micro-circulatory bed. These vessels are named as the “heart”of the microcirculatory system and provide the “vis atergo” for microcirculation flow. Indeed, rhythmicalcontractions and relaxations in the arterioles walls arethe source of the force (“vis a tergo”) that drives andregulates the blood flow into the microcirculation bed.Fluctuations in systemic pressure are almost com-pletely damped out by the arterioles at the level ofmicrocirculatory flow (Figure 3).

Finally, in vein vessels the wall is quite thin but con-tains a muscular layer of smooth myocytes that allowsthe vessels to expand or to contract and therefore, tocollect or release large blood volumes into the circu-latory bed.

Microcirculation regulation

Under normal circumstances, continued adequateperfusion of individual vascular beds is assured by thecapacity of blood vessels and heart contraction. Bloodvessels are regulated by nervous, hormonal and localstimuli.5

Neurogenic regulation of blood circulation, pro-vided by the autonomic nervous system, affects gen-eral functions such as the distribution of flow to dif-ferent organs of the body, the strength the heart pumpand the rapid regulation of blood pressure.

The autonomic regulation of circulatory vessels ismainly due to sympathetic adrenergic fibres, whilethe parasympathetic nerves mainly act on the heart

functions and exert only a minor effect on the vessels.Sympathetic vasomotor fibres originated in the spinalcord travel with the thoracic nerves and the two upperlumbar nerves to reach the ganglia of sympatheticchain from which they depart using two different waysto innervate the circulatory system: 1. “specific sym-pathetic nerves” to supply the heart and the major ves-sels 2. “spinal nerves” to regulate peripheral territories.5

The Sympathetic system provides innervations forall the vascular systems (including arterial and venoussystems) with the only exception of capillaries, pre-capillary sphincters and the majority of metarterioleswhich are mostly regulated by humoral local factors(Figure 4).

The vasomotor centre (located in the reticular areaof the medulla and in the third inferior of the pons )repeatedly transmits signals to the sympathetic vaso-constrictive fibres at a rate of 0.5-2 per second. Thiscontinuous discharge is called as sympathetic vaso-motor tone and allows a persistent partial contractionof the vessels wall.

Any increase in sympathetic autonomic system out-put enhances wall vessel contractility (vasomotoreffect), peripheral resistance and cardiac filling pres-sure and decreases vessel capacitance and circulatingblood mass. The nervous autonomic system plays a

VISA

TERGO

ARTERIOLEMETARTERIOLE

Figure 3.—Microcirculatory arterioles and metarterioles: vis a tergo.Arterioles and metarterioles represent a major site for regulating systemicvascular resistance in the microcirculatory bed. These vessels are the“heart” of the microcirculatory system and provide the “vis a tergo” formicrocirculation flow. Indeed, rhythmical contractions and relaxations inthe arterioles walls are the source of the force (“vis a tergo”) that drives andregulates the blood flow into the microcirculation bed. Fluctuations insystemic pressure are completely damped out by the arterioles at the lev-el of microcirculatory flow.



main regulatory function by inducing significantchanges in filling and capacity.

However, autonomic system is only just involved inthe changes of tissue blood flow, the main regulation oftissue perfusion being driven by local factors (Figure 5).

An essential principle of the circulatory function isthe ability for each circulatory district to regulate localperfusion according to the specific metabolic necessity.Since in each tissue metabolic requirements vary overthe time, local flow accordingly changes. Indeed, localflow needs depend from variable tissue metabolicrequirements such as O2 provision, nutrients supply(glucose, lipid, amino acid….), CO2 removal, preser-vation of an appropriate ionic tissue concentration andhormones transportation.

Furthermore, there are some tissues with specificfunctions and requirements. Blood vessels of the skinneed to fulfil at least two functions: nourishment andthermoregulation. By regulating skin capillary perfu-sion, heat loss may significantly vary. At the renal lev-el, local circulation allows the removal of metabolicwasted contributing to the emunctories (depurative)function.

As a general rule, the higher the metabolic tissueactivity, the higher the local blood flow requirement.At rest, in the muscle tissue there is little metabolicactivity and consequently, the basic flow is very low (4ml/minute/100 g). However, with strong physical activ-ity, muscle metabolic requirements can increase formore than 60 folds and blood flow can increase formore than 20 folds (up to 80 ml/minute per 100 g).5

Tissue flow is regulated by the release of severallocal factors (Figure 5).

All these local factors contribute to regulate local per-fusion in short and long term.

Factors regulating short term local perfusion include:CO2 (carbon dioxide), lactic acid, adenosine derivates,phosphates, histamine, potassium, hydrogen ions.

Local factors regulating tissue flow in the long terminclude endothelial growth factors, fibro cells growthfactors and angiogenine.

Short term regulation of tissue perfusion (by CO2and adenosine) is determined by the enhancement inrhythmic dilations and constrictions of vessel wall at thelevel of arterioles, metarterioles and precapillary sphinc-ters (“increased vasomotion”) with correspondent flowmodifications. These changes of local flow occur with-in few seconds or minutes with the purpose to maintainperfusion appropriate to local metabolic requirements.

Long term regulation of local flow (mediated bygrowth factors) is managed by the expansion of themicrocirculatory bed (“true” and “false” angiogenesis).This vascular bed increase may require few days,weeks or some months.

Vasomotion

A single metarteriola, a single capillary and the sur-rounding tissue form a tissue unit. Precapillary sphinc-ters are located at the proximal level of the capillaryvessels while several smooth muscle fibrocells sur-round the metarteriola.

Sympatheticnervous system

Arteriola

Metarteriole

Venule

Capillare

Localfactors

Arteriola

Sfinteriprecapillari

Figure 4.—Interaction between Sympathetic innervations and local factorsin vessels regulation.

Figure 5.—Microcirculatory network and regulating factors. Top, left:shortterm regulating factors. Bottom on the right: long term regulating factors.

Arteriole

Venule

CARBON DIOXIDE, ADENO-SINE, ADENOSINE DERIVATES,PHOSPHATES, HISTAMINE,PATASSIUMIONS, HYDRO-GENESIONS- LACTIC ACID

ENDOTHELIAL CELLS GROWTH FACTORS,FIBRO-CELLS GROWTH FACTORS, ANGIOGENINE



Experimental models on wing bat under microscopymagnification, have shown that precapillary sphinctersmay be opened or closed and the metarteriole tone(persistent basal contraction of muscle cells in vesselwall) may change over the time. At a definite time,the number of opened precapillary sphincters corre-sponds to the tissue requirements for oxygen and nutri-ents in that time. Furthermore, sphincters and metar-terioles can open and close cyclically, several timesper minutes. This rhythmic (at regular intervals) open-ing and closing of metarterioles and precapillarysphincters is named vasomotion.

Since smooth muscle cells require oxygen to beginand maintain contraction, the contractile strength ofprecapillary sphincters increases when oxygen avail-ability rises.

Therefore, when oxygen concentration increasesabove a threshold level, precapillary sphincters andmetarterioles close down and tissue flow slows until theexcess of oxygen is completely utilized by the tissuecells. On the contrary, any decrease in oxygen con-centration causes the release and complete openingof metarterioles and precapillary sphincters with asubsequent enhancement in flow velocity and tissueperfusion.

Short term local flow regulation

Short term regulation of tissue flow is mainly deter-mined by local factors: CO2, adenosine, lactic acid,phosphates, histamine, potassium, hydrogen ions.

This short term regulation is mediated by vasodi-latation at metarterioles and arterioles level due to therelaxation of smooth muscle cells in the vessels walland the enhanced vasomotion. These adjustments occurwithin few seconds or minutes to rapidly adapt localflow to tissue requirements. Short term regulationcauses abrupt modification of local perfusion due to avery consistent change in the contractile tone of arte-rioles, metarterioles and precapillary sphincters.

Several factors interact for short term regulation,including tissue metabolism, oxygen and nutrientsavailability.

Tissue metabolism: It has been shown that 8 foldsincrease in tissue metabolism is followed by 4 timesincrease in the local flow.

Consequences of Oxygen and metabolic availabil-ity on local flow: at any time local oxygen availabili-ty decreases, such as in the altitudes, during pneumo-nia and in poisoning from carbon monoxide (that

reduces haemoglobin ability of carrying oxygen) orcyanides (that reduce oxygen utilization from tissues),as a consequence local blood flow significantly increas-es.

Two different theories are suggested to explain flowchanges due to metabolic or oxygen variations:

— Flow dependent regulation (Vasodilatationhypothesis);

— Oxygen requirement hypothesis.

THE FLOW DEPENDENT REGULATION OF VASOMOTOR TONE

(VASODILATATION HYPOTHESIS)

According with the vasodilatation theory, the greaterthe metabolism or the lower the oxygen availability, thehigher the release of strong vasodilator factors thatact by increasing arterioles, metarterioles and pre-capillary sphincters relaxation. This allows substantialvasodilatation and enhanced flow. Several factors havebeen described as putative mediators of the couplingbetween oxygen consumption, metabolism increaseand vasomotor tone (vasodilatation stimulating fac-tors, released in condition of increased metabolism ordecreased oxygen availability) such as adenosine, CO2,lactic acid, adenosine derivates, phosphates, hista-mine, potassium and hydrogen ions.5

Recently, particular attention has been paid to therole of adenosine as one of the most powerful vasodila-tors acting directly (via the A2 receptors) upon thesmooth muscle cells of coronary arteries. The hypoth-esis that adenosine could represent a major signal cou-pling the myocardial metabolism and the coronaryflow is supported by the observation that its actualconcentration in myocardial interstitium is indeedwithin the range of its vasoactive effect. When coronaryflow is reduced, interstitial adenosine levels increase:this is followed by active coronary artery vasodilata-tion and re-established coronary normal flow. Similarly,in cases of heart hyperactivity and increased metabo-lites and oxygen consumption, an increase in tissueATP degradation with increased adenosine produc-tion has been observed. It has been hypothesized thatthe released adenosine, in part, passes outside the mus-cle cell and stimulates coronary arteries vasodilata-tion in order to adapt coronary flow to the increasedoxygen requirements due to the increased heart activ-ity.5

Many Authors suppose that the CO2 promotesvasodilatation at arterioles and metarterioles levels



using a mechanism similar to that of adenosine.Increase in interstitial CO2 tension has indeed beenconsidered a potential signal responsible for the meta-bolic control of the coronary blood flow. The CO2 pro-duced during increased myocardial activity directlystimulates coronary vasodilatation in order to increasethe coronary flow and to adapt this to the increasedcardiac oxygen requirements consequence of theincreased activity.

Both, adenosine and CO2, are physiologic factorsused for the “autoregulation” of local flow, that is theadjustment of local perfusion to metabolic and oxygentissue requirements.

THE OXYGEN REQUIREMENT HYPOTHESIS

The flow dependent regulation of vasomotor tone isaccepted by many Authors. However, Others supporta different mechanism to explain changes in tissueflow: the hypothesis of “the oxygen requirement”, orbetter, “the nutrients requirement” since besides oxy-gen, many other local nutrients may be probablyinvolved in local flow regulation.5

Oxygen (such as other nutrients) is needed to main-tain the contraction of smooth muscle cells of the arte-rial wall (vasomotor tone). In situations of scarce avail-ability of oxygen (and other nutrients), arterial ves-sels tend to relax and dilate. Similarly, during increasedmetabolic activity, the augmented oxygen consumptioncould cause a decrease in oxygen availability for ves-sels smooth muscle fibro cells with consequent localarterial vasodilatation.

Long term tissue flow regulation

The regulation of tissue flow in the long term isbased on the enlargement of the microcirculatory vas-cular bed. A “true Angiogenesis” and a “falseAngiogenesis” are involved in obtaining the expan-sion of microcirculatory bed.9

True angiogenesis

The term “angiogenesis” refers to the growth, expan-sion and remodelling of vessels. This process occursas a consequence of various angiogenic factors thatmay be released from ischemic tissues, rapid grow-ing tissues or tissues with increased metabolic activi-ty.

Today more than 12 angiogenesis factors have been

individuated. All of these are small peptides. The threemost known factors being:

— endothelial cell growth factors;— fibroblast growth factors;— angiogenine.These factors have been isolated from tumoral cells

or ischemic tissues. It has been hypothesized that thelack of tissue oxygen is the main cause for the pro-duction of angiogenic factors. Each of these factorspromotes development of new vessels by the samemechanism of sprouting, growing and remodellingfrom venules and, more rarely, from capillaries. Newarterioles and metarterioles are indeed generated.5

Hypoxia is a strong stimulus for angiogenesis andtherefore, for the regulation of flow in the long term.Indeed, an increase in microcirculatory bed has beenfound in several animals living in altitudes whereatmosphere oxygen concentration is low. Other exper-imental studies have been performed in chickenembryos incubated in low oxygen atmospheres: devel-opment of microcirculatory bed has been doubled withrespect to normal animals.

Furthermore, in immature neonates who undergooxygentherapy it has been shown that the increase inoxygen availability causes a rapid interruption in thephysiologic process of retinal vessels neoformation,and even the degeneration of some formed capillaries.Subsequently, when the cycle of oxygen-therapy iscompleted and the newborn returns to a normal oxy-gen atmosphere concentration, the new condition of rel-ative hypoxia provokes an impulsive fast growth ofnew vessels. In some circumstances this growth maybe excessively chaotic to cause invasion of the vitre-ous from the neogenerated vessels and consequentlyblindness (retrolenticular fibroplasias).

The Angiogenesis process can be stimulated bydecreased availability of oxygen and, consequentlyby an excess of CO2. CO2 may promote the release oflocal growth factors able to stimulate angiogenesis.

The extend of tissue vascularization (angiogenesis)can increase or decrease according with the metabol-ic activity of the same tissue. If metabolism increases(and therefore the release of CO2 is high), tissue vas-cularization expands; vice versa, when metabolic activ-ity decreases (and the CO2 concentration is low), tis-sue vascularization concurrently shrinks. In conclu-sion, in true angiogenesis there is a constant remodelingof microcirculatory vessels according with tissue meta-bolic requirements.



False angiogenesis

The theory of “false angiogenesis” was ideated byCurri.11 The Author suggested that CO2 promotes theexpansion of microcirculatory bed by the recanaliza-tion of virtual capillaries. This “false angiogenesis”is not directly stimulated by CO2 but is the conse-quence of the increased tissue flow. The term “falseangiogenesis” was used because the increase in vas-cular bed was not due to neoformation of new vesselspromoted by growth factors, but for the recanaliza-tion of pre-existent virtual capillaries.

True and False angiogenesis might cooperate indetermining the increase of microcirculatory vascularbed. Indeed this expansion in vascularization may beconsequence from the combination of:

— a true angiogenesis (vessels neoformation) stim-ulated by endothelial and fibroblast growth factorsand angiogenine;5

— a false angiogenesis, that is the recanalizationof virtual capillaries stimulated by the notably increasedlocal flow velocity and volume.9

Carbon DIOXIDE (CO2)metabolism and excretion: biochemical essentials

Carbon dioxide (CO2) formed during cellular metab-olism moves across the cell wall (from inside to out-side) in a gaseous status to be removed. This is becauseonly a very small amount of CO2 can diffuse as bicar-bonate ions that are almost completely impermeable tothe cell wall.7 After entering into the capillary bed,CO2 undergoes several physical and biochemical reac-tions that allow its transformation and delivery to tis-sues.

— A small fraction (~7%) of the overall plasmaticCO2 is carried to the lungs as a dissolved gas (in solu-tion).

— The majority (~70%) of CO2 reacts with plas-matic water to form carbonic acid : CO2+H2O →H2CO3. This reaction, naturally occurs so slowly (1-3minutes) in the plasma to loose any relevance. At theopposite, the Erythrocytes contain a specific catalyticenzyme, the “carbonic anhydrase”, that is able toincrease for about 5000 times the reaction speedy. Dueto carbonic anhydrase the reaction becomes so fast toreach the steady state in less than 1 second. 7 Therefore,a large fraction of CO2 is already transformed in car-

bonic acid into the red cells before to leave the capillarybed. Within another fraction of a second, carbonic aciddissociates by loosing a proton to become bicarbon-ate: H2CO3 → H+ + HCO3

-. Most of the protons(Hydrogen ions) then combine with haemoglobin inone of the main buffer systems of the red cells.Bicarbonate is rapidly carried outside the red cells withthe help of a carrier protein located on the cell wallthat allows rapid exchange, in opposite directions,between bicarbonate ions that are expelled and Chlorideions that are carried in (“Chloride ions exchange”).Therefore, chloride ions concentration in the red cellsof venous blood is lower that in the red cells of thearterial blood. This reversible binding between CO2and water within the erythrocytes is the main carrierused in human body to carry 70% of CO2 from tissuesto lungs. It has been shown in experimental modelsthat by using an inhibitor (e.g., acetazolamide) to blockcarbonic anhydrase activity in the red cells, the CO2removal is significantly lowered and levels of tissuePCO2 can increase from 45mmHg to 80 mmHg!.

— Another fraction of CO2 binds to the ammineradicals (heme sites) of haemoglobin to form car-bamylhemoglobin (CO2Hb). This is a weak andreversible binding that allows the rapid release of CO2in the pulmonary alveoli where PCO2 is lower than inthe capillary bed.

— Finally, a small fraction of CO2 combines withplasmatic proteins by the same bindings used withhaemoglobin. However, these reactions between CO2and plasmatic proteins are significantly slower thanthat catalyzed in erythrocytes by carbonic anhydraseand can contribute for only 20% of CO2 transporta-tion.

At the capillary level, carbonic acid produced fromCO2 dissociation decreases the pH of the blood.However, the interaction between this acid and plas-matic buffers prevents the excessive increase in bloodprotons level and therefore, avoids acidosis.

The effects of carboxytherapyon the microcirculation

The purpose of Carboxytherapy is to improve orrestore microcirculation function when damaged. Thefinal effect is that of a rehabilitation therapy for micro-circulation.

The results of CO2 administration are not only due



to the improvement of local parameters of circulationand tissue perfusion but also to the instigation of apartial increase in oxygen tension as a consequence of: a hypercapnia-induced rise in capillary blood flow;a drop in cutaneous oxygen consumption; or a rightshift of the O2 dissociation curve (Bohr effect).

The effects of Carboxytherapy in instigating vasodi-lation are due to interactions between the released CO2and factors regulating tissue flow either in short orlong term. It has been shown that CO2 administrationcan determine:

Improvement in local tissue blood flow velocity; Increase in microcirculatory vascular bed (angio-

genesis).1) The increase in tissue blood flow velocity are due

to the effects of CO2 at different levels:— CO2 interferes with the “vis a tergo” of the micro-

circulatory system by increasing the elastic retractionin arterioles/metartaerioles and indeed by inducingvasodilatation;14

— CO2 relaxes smooth muscle fibro cells of pre-capillary sphincters allowing opening of sphinctersand therefore an increase in tissue flow velocity;

— CO2 enhances erythrocytes deformability.10, 11

The contraction of smooth muscle cells within themuscular layer of vessel wall requires oxygen.Therefore, oxygen provokes contraction of the metar-terioles and precapillary sphincters with a consequentvessel narrowing and a decrease in tissue blood veloc-ity and flow.

On the contrary, CO2 administration determinesrelaxation of the smooth muscle cells in the metarte-rioles and precapillary sphincters with a consequentincrease in the flow velocity and an overall improve-ment in the tissue perfusion. This enhanced vasomo-tion is the critical factor in determining the increase inlocal tissue perfusion. Indeed, this vasomotion repre-sents the “vis a tergo” of the microcirculation that dri-ves blood flow towards the capillary bed.

2) The effect of CO2 as a main regulating factorinducing true and false angiogenesis has been detailedabove.

Carboxytherapy:contraindications and side effects

Side effects from Carboxytherapy include minorpain, aches, ecchymoses, and local crackling or burn-

ing sensation. Major adverse events are uncommon.Indeed, it has been demonstrated in studies on gynae-cologic laparoscopic surgery that even large amountsof CO2 can be used to expand abdominal cavity (even2-4 liters of CO2) without any toxic effect. At rest,with normal ventilation (ventilation 6 l/min) the humanbody consumes 250 mL/min of Oxygen (transportedfrom lungs to tissues) and exhales 200 mL/min of CO2(removed from tissues and excreted through pulmonaryalveoli). In condition of hyperventilation, Oxygen con-sumption can increase up to 4000-5000 ml /minuteand CO2 can be formed up to 4000-4500 ml/minute. (5)During carboxytherapy an average of 30-50 ml/minuteCO2 are administrated per session: the mild increase inCO2 levels are easily and therefore promptly resolvableby a mild hyperventilation at the end of treatmentwithout risk of hypercapnia and respiratory acidosis.10

Nevertheless, in patients with severe respiratoryinsufficiency, severe renal failure or chronic congestiveheart failure Carboxytherapy should be contraindi-cated. The main excretion of CO2 and protons (H+) isperformed by the kidneys and the lungs. Severe dam-ages of these organs (renal or respiratory failure) maycause excessive accumulation of CO2. Furthermore, incongestive heart failure, vessel circulations markedlyslow down and consequently, the amount of CO2removal from tissues is significantly lowered. Chroniccongestive heart failure is another pathophysiologiccondition causing CO2 accumulation in which car-boxytherapy is questionable.14

Carboxytherapy should be also avoided in patientsunder treatment with carbonic anhydrase inhibitors(acetazolamide, diclofenamide, etc..). Indeed, the useof the inhibitor obstacles the main process by whichCO2 can be carried to be excreted trough lungs andkidneys. Therefore, an excessive increase in CO2 lev-els during carboxytherapy might occur.

Severe anaemia might be another contraindication.This is because the significant reduction in erythro-cytes and haemoglobin levels of anaemic conditionstranslate into a significant deficit of two of the mainphysiologic systems used for CO2 elimination: thebinding with water at the level of the erythrocytes andthe direct interaction with plasmatic haemoglobin. 1.Severe anaemia implies a significant decrease in redcells number, therefore a significant decline in theavailability of the main carrier by which CO2 can beusually transferred to the lungs and kidneys to be elim-inated 2. Severe anaemia implies also a decrease in



the haemoglobin levels and this reduces also the pos-sibility of CO2 binding to form carbamylhemoglobinplasmatic, the second most relevant CO2 carrier fromtissues to lungs and kidneys. Therefore, in condition ofsevere anaemia, CO2 administration to perform car-boxytherapy can further and dangerously increase CO2levels and cause severe hypercapnia and acidosis.14

A decrease in plasmatic protein levels (and conse-quently in carbamylhemoglobin and plasmatic pro-teins) may be caused by chronic liver insufficiencythat, indeed, constitutes another contraindication forcarboxytherapy.

Other contraindication is the presence of gaseousgangrene. This severe infectious disease is caused byanaerobic bacteria entered in the body through skinwounds and is characterized by extensive tissue dam-ages, necrosis, oedema, and severe generalised dete-riorated conditions. The infection from anaerobic bac-teria (Welchia perfringens, Clostridium septicum,Clostridium novyi, Clostridium sporogenes, Clostri-dium hystoliticum) may be further enhanced by theincreasing in CO2 level that favours anaerobic envi-ronment (because of the concomitant decrease in O2concentration).

In conclusion, in physiological status any mild hyper-capnia is rapidly compensated by an increase in the pul-monary ventilation that increases CO2 excretion.Therefore, severe hypercapnia and acidosis never occuralso after an excessive CO2 administration. In normalcondition (health patients) there is no possibility tocause severe hypercapnia by carboxytherapy.

Hypercapnia occurs when the lungs are unable toexcrete CO2 and therefore pCO2 significantly increas-es at the alveoli level. When alveolar PCO2 reaches60-75 mmHg the patient experiences severe dyspnoea.With further increase up to 80-100mmHg he becomesdrowsy and lethargic (hypercapnic coma). With PCO2alveolar levels of 120-150mmHg the excessive CO2dampens respiratory bulbar center (normally smallconstant CO2 levels are necessary to stimulate the cen-tre) and can cause death.5

Carboxytherapy:clinical indications in phlebology

For all the effects on the microcirculation Carboxy-therapy can be used to treat:

— chronic venous insufficiency (CVI);

— chronic veno-lymphatic insufficiency (CVLI);— venous ulcers.

Other indications

— Localized adiposities (cellulitis);— psoriasis;— arterial vascular pathologies (Buerger disease,

diabetic ulcers, acrocyanosis, atherosclerotic ulcers);— aesthetic body disease (skin laxity, skin aging);— rheumatism (acute or chronic).

Carboxytherapy: administration techniques

Two methods for CO2 administration are employed:— percutaneous;— subcutaneous injection.

Percuteneous administration

Includes: gaseous baths and gaseous shower.For gaseous baths CO2 may be by administered as:— true gas spring (carbon dioxide fumarole);— carbonated water (carbon dioxide water).Gaseous baths may be generalized or partial. For

generalized administration, the patient lies supine orsit down. The entire lower body of the patient is drawnin a hermetically closed plastic bag where CO2 is insuf-flated in order to create a saturated CO2 atmospherearound the patient’ legs. These generalized true gassessions are usually applied for 20-30 minutes per dayand repeated per 20-30 days.

Partial administration technique is applied in casesof localized functional or organic, arterial or lym-phatic, disease: a single limb (or part of this) is drawnin the plastic bag that is then hermetically ensuredaround the limb and insufflated with CO2.

An example of ambulatory gas bath application is theHydrocarboxytherapy (Figure 6).

Carbonated water baths are applied with the fullimmersion of the patient in carbonated water at a tem-perature of 34°. It can be used natural carbonated wateror water artificially enriched with CO2 jets. Treatmentis applied for mean of about 20-30 minutes per day andrepeated for about 20-30 consecutive days.11

Gaseous showers are usually applied for the treat-ment of lower limbs dystrophic ulcers and include:



— point gas showers: CO2 is released throw a smallhole at the tip of a pipe. This technique is used fortreatment of isolated small ulcers;

— loco-regional gas showers: CO2 jets are provid-ed from a multi –holes spring ramp where the limb islocated after being draped and closed in a plastic bag.

Gas showers are applied for a mean of 20-30 min-utes per day in cycles of 20-30 days.

Subcutaneous injections

The most common employed method to administrateCarboxytherapy is by subcutaneous injection (hypo-dermic injection). While CO2 baths and showers (eithergaseous or carbonated water) are applied as thermaltherapeutic practice (balneotherapy), CO2 injection canbe administered exclusively in medical settings suchas ambulatory practice. Since its first introduction, tech-nology has evolved: in the first times gas bottles andsyringes were used. Today, electronic programmabledevices are available that allow accurate release of puri-fied and precise CO2 volumes. A number of filters,located inside the device, separate CO2 from contami-nates such as Clostridium sporogenes spores. Perfectlymeasured volumes of CO2 gas are indeed released in awell depurated form to reach the delivery system pro-vided with 30 G (13 mm) terminal needle.Once theCO2 supply starts, few seconds are needed to completelyfill the device and to ensure a saturated CO2 atmos-phere within the delivery system. Therefore, the needleis introduced into the hypodermic layer and the CO2

injections causes subcutaneous emphysema. The nee-dle is ensured to the skin with a bandage, while CO2continues to spread within the subcutaneous tissue fol-lowing virtual routes until the achievement of the pre-definite volume. CO2 diffusion and velocity of hypo-dermic dispersion strictly depends on the laxity of sub-cutaneous tissues and may vary from patient to patient.

Dosage

From few mL up to 2000 mL of CO2 are adminis-trated in each carboxytherapy session. Usually themedium CO2 flow is of 30-50 mL/minute. But, in thefirst 2-3 minutes lower flows can be used (10-20ml/min) in order to reduce the itchiness or pain sen-sation that could be evocated when CO2 starts to pushthe way through the subcutaneous layer. After this firstphase (about 2-5 minutes) CO2 flow can be safelyincreased to 30-50 ml/minutes.9

Sites of injection

In condition of lower limbs severe lymphatic sta-sis, subcutaneous injections are applied at sub-trochanteres levels: anteriorly and posteriorly, at themedium, medial and lateral thirds of the thigh (Figure7). Needles are ensured to the skin and the CO2 isrealeased to reach the established dosage.

Literature data and personal experience

Recent studies have confirmed the vasomotor effectsof CO2, in addition to the absence of relevant side-

Figure 6.—Hydrocarboxytherapy (ME.DI.TER).

Figure 7.—Subcutaneous injection: Subtrochanteric site.



effects and toxicity. Curri et al.,1, 4 by using Doppler andLaser Doppler and Albergati and Parassoni et al.1 byusing optic video capillaroscopy (VCSO) verified theincreased vasodilatation in the arterioles and metarte-rioles and the increased vasomotion. An increase infemoral blood flow of te lower limbs, as well as animprovement in treadmill test perimeters were observedby Hartmann and Savin who proposed this treatmentfor obliterating arteriopathies.6, 12 Brandi et al.3 foundthat the effect of Carboxytherapy on microcirculationwas a positive tool in the physiological oxidative lipoly-tic process and therefore suggested this gas for thetreatment of localized adiposities. Indeed local adi-posities are commonly associated with alterations inblood and lymphatic drainage. They reported signifi-cant variations in the maximum circumference of low-er limbs, in the microcirculation studied by oxygentension (tcPO2) and Laser Doppler, and in the histo-logical analysis of adipose and connective tissues,after this treatment.3

More recently, studies have focused on the effectof Carboxytherapy on lymphatic drainage. Indeed, thepositive effect of Carboxytherapy in improving micro-circulatory flow was found to translate into a similarbenefit in increasing the lymphatic drainage. In 2006,Manzo, Villeggia and Verlaro showed by lym-phoscintigraphy the improvement in local parametersof circulation and tissue perfusion caused by Carboxy-therapy in patients with severe lymphatic stasis.8 Asignificant decrease of lymphatic stasis and a docu-

mented re-establishment of the physiological lym-phatic drainage was found in the treated cases.Furthermore, there was a clinical improvement dueto a significant limb volume and circumference reduc-tion. The Authors experience is detailed here follow-ing.

Figure 8.—Lymphoscintigraphy: basal radionuclide scan. Top, left: legs,anterior view. Top, right: legs by posterior view. Bottom, left: thighs ante-rior view. Bottom, right: thighs, posterior view.

Figure 9.—Lymphoscintigraphy: radionuclide scan after walking (30 min-utes). Top, left : legs, anterior view. Top, right: legs by posterior view.Bottom, left: thighs, anterior view. Bottom, right: thighs, posterior view.

Figure 10.—Carbomed CDT Evolution (Carboxytherapy Italian device).



In a two years period (2004-2006) a total of 15female patients affected by severe limphedema weretreated by Carboxytherapy: the effects on the lym-phatic flow were analysed. Before treatment, all thepatients were evaluated by clinical examination, echo-color Doppler and lymphoscintigraphy. Lymphoscinti-graphy was performed using computerised gammacamera with double rectangular head (GE Xeleris) byadministrating 0.1 ml 99mTc-Albumin monocolloidthrough the 1st interdigital dorsal space of the foot(Figures 8, 9). For each patient 10 weekly sessionsof subcutaneous Carboxytherapy using a program-

mable CO2 apparatus (Carbomed CDT Evolution byLED SpA, CE0051- classe IIb-ISO 9001-csq-csq med -Iqnet; Figure 10) were applied. The totalquantity of CO2 administrated by week was of 1000mlper side. In all the patients elastic compression wasalso applied before treatment and maintained for allthe period of the study and thereafter. After a weekfrom the last Carboxy-therapy session patients under-went a new lymphoscintigraphy examination.According with the final radionuclide scan imaging inall the patients the physiologic lymphatic flow wasrestored in lower limbs. This result was associatedwith a decrease in limb volume and lymphedemareduction. Post-treatment radionuclide results areshown in Figures 11, 12.

Conclusions

Due to the vasomotor effects of CO2 and the absenceof relevant major side-effects and toxicity, Carboxhy-therapy has become increasingly diffused for the treat-ment of a variety of microcirculatory diseases.Specifically, the positive effect on lymphatic drainagein microcirculation let to use Carboxytherapy as aneffective therapy for patients with lymphatic stasis.

Riassunto

Carbossiterapia: effetti sulla microcircolazione e suo uso neltrattamento dell’edema linfatico grave. Una review

Per carbossiterapia si intende l’utilizzo dell’anidride car-bonica allo stato gassoso a scopo terapeutico. La carbossiter-apia esplica i suoi effetti interferendo con i fattori che regolanoa breve e a lungo termine il flusso ematico tessutale locale.La carbossiterapia esplica i suoi effetti a livello di microcir-colazione: a livello delle metarteriole, delle arteriole, deglisfinteri precapillari determinando un aumento della velocità delflusso ematico tessutale locale e quindi un aumento del flus-so linfatico. Una revisione della letteratura mostra come oggila Carbossiterapia rappresenti un campo in continua espan-sione per il trattamento di patologie sia flebologiche che nonflebologiche. Vengono qui riportati i principi fondamentali diemodinamica, istologia e biochimica che spiegano l’effettodella Carbossiterapia sul microcircolo e sul drenaggio linfati-co. In particolare l’effetto positivo della Carbossiterapia sul-l’incremento del drenaggio linfatico tissutale (a livello delmicrocircolo) ha portato ad una sua rivalutazione nel trattamentodell’edema linfatico degli arti inferiori.

Parole chiave: Carbossiterapia - Microcircolo - Linfedema.

Figure 11.—Lymphoscintigraphy: radionuclide scan after 10 sessions ofsubcutaneous Carboxytherapy (1000 mL CO2 by side). Top, left : legs, ante-rior view. Top, right: legs by posterior view. Bottom, left: thighs anteriorview. Bottom, right: thighs, posterior view.

Figure 12.—Lymphoscintigraphy: final radionuclide scan after walking (30minutes) + 10 sessions of subcutaneous Carboxytherapy (1000 mL CO2by side). Top, left : legs, anterior view. Top, right: legs by posterior view.Bottom, left: thighs, anterior view. Bottom, right: thighs, posterior view.



References

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2. Belotti E, De Bernardi M. Utilizzazione della CO2 termale nellaPEFS. Riv. La Medicina Estetica, anno 16, n.1-2 gennaio-giugno1992. Editrice Salus Internazionale, Roma.

3. Brandic C, D’Aniello C, Grimaldi L, Bosi B, Dei I, Lattarulo P,Alessandrini C. Carbon dioxide therapy in the treatment of localizedadiposities: clinical study and histopathological correlations. Aesth PlastSurg 2001;25:170-4.

4. Curri SB, Bombardelli E. Local lipodystrophy and districtual micro-circulation: proposed etiology and therapeutic management. CosmetToilet 1994;109:51.

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application of carbon dioxide in intermittent claudication: results ofa controlled trial. Angiology 1997;48:957

7. Lehninger AL. Principi di biochimica, 1992. Zanichelli Editore,Bologna.

8. Manzo G, Villeggia P, Varlaro V. La carbossiterapia utilizzata in situ-azioni cliniche di linfostasi a carico degli arti inferiori: valutazione deglieffetti mendiante linfoscintigrafia – Abstract Book- XXVII CongressoNazionale della Società Italiana di Medicina Estetica – Riv. LaMedicina Estetica, anno 30, n. 1, gennaio-marzo 2006. Editrice SalusInternazionale, Roma.

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10. Parassoni L,Albergati F, Varlaro V, Curri SB. La carbossiterapia in temadi meccanismi d’azione. Riv. La Medicina Estetica, anni 21, n.1, gen-naio-marzo 1997. Editrice Salus Internazionale, Roma.

11. Parassoni L, Lattarulo P, Albergati F, Varlaro V, Guidi F.Carbossiterapia. Da Bartoletti C.A: Medicina Estetica, 1998. EditriceSalus Internazionale, Roma.

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13. Varlaro V, Parassoni L, Bartoletti CA. La carbossiterapia nella PEFSe nell’adiposità localizzata. Riv. La Medicina Estetica, anno 19, n.1,gennaio-marzo 1995. Editrice Salus Internazionale, Roma.

14. Varlaro V, Bartoletti CA. La carbossiterapia. Riv. La Medicina Estetica,anno 29, n.3, luglio-settembre 2005. Editrice Salus Internazionale,Roma. Pagg. 417-438.

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Carboxytherapy: effects on microcirculation and its use in the … · 2017-11-06 · the effects on microcirculation bed and lymphatic drainage are here analyzed to show how Carboxytherapy