Sugical Anatomy of Liver Simplified for General Surgeons

I feel that the only reason general surgeons fear from liver is because lack of understanding or poor understanding of its anatomy.

And complicated segmental anatomy given in general surgery text books without proper explanation.(though very important and every surgeon should read it before reading my post.)

First forget about segments. You will be doing segmentectomies very rarely.

Just remember following terminologies:

1.     Right lobe

a.     Right anterior sector

b.     Right posterior sector

2.     Left lobe.

a.     Left Letral segment

b.     Segment 4

3.  Caudate lobe

Vascular structures that you can dissect extrahepatically in porta. (Dissect slowly and carefully you just need to denude porta and you can do each type of liver surgery)

Ø  Hepatic artery proper (hepatic artery after gastroduodenal artery before that it is called common hepatic artery)

o   Right hepatic artery (mostly branch from hepatic artery proper or lie posterior to the bile duct when arises from SMA)

§  Right anterior sector artery

§  Right posterior sector artery

o   Left hepatic artery

§  Segment 4 artery (some time it arises from right)

Ø  Bile Duct:

o   CBD

o   Right hepatic duct

o   Left hepatic duct

                                

Technically You can see these structures in the porta outside liver but my plan in liver resections generally is quite simple dissect all the vascular structures and rest is bile ducts. Cut it in the end after parenchymal transection.

Ø  Hepatic veins: (at the top when you dissect falciform ligament)

·      Right hepatic vein

·      Middle left vein together

Inititally dissect falciform ligament until you can see right and left-middle vein insert in to IVC and dissect groove between right and middle- left.

·      Inferior hepatic veins: draining directly from right lobe to IVC on right side and caudate vein found on left side.

Now Few Simplified Anatomical Definitions of Liver lobes according to venous drainage

Right lobe: Liver tissue right to middle hepatic veini

Left lobe : Liver tissue left to middle hepatic vein.

Most people say middle hepatic vein is a part of left lobe but for me as a surgeon for better understanding I take middle hepatic vein as no man’s land. Like Indo China border dispute and I act as U.N. so I give land according to the need.

If middle hepatic vein is involved with tumor or tumor is very close my right hepatectomy will include middle hepatic vein also or in case of transplantation when graft volume is border line or CT shows right anterior sector is draining mostly in to middle vein.I will take middle hepatic with the right lobe.

If tumor is far away from middle hepatic I will keep middle hepatic vein with the left side. Or in case of transplantation when right vein is dominantly draining anterior or graft volume is adequate I will keep middle vein with the left lobe.

Same goes with left hepatectomy in transplantation when you are taking left lobe middle hepatic vein almost always remains with the left lobe.

Right anterior sector: area between middle hepatic and right hepatic vein.

Right posterior sector: area Right to right hepatic vein including right hepatic vein area.

Left lateral sector liver tissue left to falciform ligament

Segment 4 area between facifom ligament and middle hepatic vein.

Caudate lobe is a seprate entity.

With these facts in the next part I will try to right simplified techniques of different hepatectomies.

A revolution in the treatment of Hepatitis C.FDA approves single tablet treatment (fixed dose combination of Sofosbuvir and ledispavir) In Genotype 1

Hepatitis C – days of interferon based treatment are gone.

Hepatitis C will be treated by single oral tablet.

Sofosbuvir alone or in combination with ladispavir – A revolution in the treatment of Hepatitis C

New England journal of medicine published 3-research article in april – may 2014.

Shows result of fixed dose combinations of two drugs (fixed dose combination means they will be available as single tablets)

 (See my previous blog in Hepatitis C for current recommendation with sofosbuvir)

In this post I will be posting about fix dose combination of Sofosbuvir with Ledispavir which got FDA approval recently.

1.     Previously Treated but failed with interferon.

·      In patients without cirrhosis this new drug combination gave Sustained Virological response (see my previous blog) in 95% of patient with 12 week therapy and 99% in 24 week therapy

·      With cirrhosis It gave response rates of 86% at 12 week and 99% at 24 week.

·      If we add ribavirin (another drug see my previous posts), It gave response rates of almost 100% without cirrhosis at 12 and 24 week without cirrhosis

·      With cirrhosis if we add ribavirin than response rates were 82% at 12 weeks and 99% at 24 weeks.

2.     Long term Hepatitis without Cirrhosis.

·      94% sustained virological response at 8 weeks and 95% at 12 weeks without ribavirin

·      93% with ribavirin at 8 weeks and 97.5 % at 12 weeks.

3.     Untreated Hepatitis C

·      95% Sustained virological response at 12 week and 98% at 24 week in sofosbuvir-ladispavir  fixed dose combination (single tablet).

·      97% at 12 week with ribavirin and 99% at 24 week.

Ø  TAKE HOME POINTS:

·      NEED OF INTERFERON WILL BE LESS AND LESS AFTER THIS DRUG AND SO WE WILL BE ABLE TO AVOID ITS TOXICITY

·      EXCELLENT RESULT IN PATIENT OF CIRRHOSIS. THIS GROUP IS LIKELY TO BENEFIT THE MOST.

·      SINGLE TABLET SO TREATMENT WILL BE EASY FOR PATIENT

·      MAY BE HELPFUL IN POST TRANSPLANT PATIENTS TO AVOID RECURRENCE. (TRIALS ARE GOING ON)

·      COST NEED TO BE DECREASED.

My newly published research article

My research article in october issue of internationally renowned  journal "experimental and clinical transplantation".

CURRENT MANAGEMENT OF BILE DUCT CANCER. HOW IT CAN BE TREATED??

Cholangiocarcinoma or bile duct cancer: how to Manage???

Cholangiocarcinoma or bile duct cancer is a cancer of bile duct. In the past it was considered as untreatable but now due to improvement in surgical techniques, it can be cured if it is diagnosed and treated in time.

Most patients are diagnosed after the age of 65, with a peak incidence occurring during the eighth decade of life. Unlike gallbladder cancer, men appear to have cholangiocarcinoma slightly more frequently than women. Known risk factors include

·      primary sclerosing cholangitis

·       choledochal cyst disease

·      chronic biliary parasitic infestation

·      and numerous chemicals, including thorotrast, asbestos, dioxin, and nitrosamines.

Bile duct cancers are usually of three types:

1.     Intrahepatic or those who arise from bile ducts insider the liver.

2.     Hilar cholangiocarcinoma or klatskin tumor which arise generally from the junction of right and left sided bile ducts.

3.     Lower bile duct cancer.

Out of these 3 types hilar cholangiocarcinoma are most common and most difficult to treat and today we will discuss mostly hilar cholangiocarcinoma

For hilar cholangiocarcinoma most commonly following classification system suggested by bismuth is used.

Type 1; Tumor below junction of right and left bile duct

Type 2: Tumor at the junction of right and left bile duct but not involvement them

Type 3 A: Tumor at the junction of right and left bile duct plus involving right

Type 3B: Tumor at the junction of right and left plus involving left

Type 4L tumor involving right and left bile duct as well as junction

Presentation or clinical features:

Symptoms associated with intrahepatic cholangiocarcinomas are nonspecific, including malaise and abdominal pain. Unlike hilar and distal cholangiocarcinomas, a minority of patients develop jaundice. Hilar and distal cholangiocarcinomas can present with nonspecific symptoms of pain, anorexia, and weight loss. Itching is a common symptom for patients with extrahepatic cholangiocarcinoma, and it typically precedes clinically apparent jaundice.

It is jaundice or the presence of abnormal liver enzymes that usually prompts medical attention.

The level of jaundice can be informative in distinguishing benign from malignant biliary obstruction; benign causes of obstructive jaundice typically produce bilirubin levels ranging from 2 to 4 mg/dL (rarely exceeding 15 mg/dL), whereas biliary obstruction from cholangiocarcinoma usually results in serum bilirubin levels greater than 10 mg/dL (with a mean level of approximately 18 mg/dL).

Diagnosis:

Apart from abovementioned clinical features diagnosis is usually achieved by imaging modalities suc as CT scan  and MRI with MRCP. Some times endoscopic ultrasound or ERCP are necessary.

Preoperative MRCP:

Treatment:

Surgical treatment is the only hope for cure in cases of cholangiocarcinoma.

ALL the cholangiocarcinoma except mentioned in following table are operable.

Criteria for Unresectability for Cholangiocarcinoma

Medical contraindication to surgical intervention

Advanced cirrhosis/portal hypertension

Bilateral second-order biliary

Main portal vein involvement

Liver Lobar atrophy with other side second-order biliary radicle involvement

 Liver Lobar atrophy with other side portal vein involvement

Advanced lymphnode involvement

Distant spread.

Surgery:

The goal of surgical therapy for cholangiocarcinoma is complete R0 resection. Complete resection has consistently proven to correlate well with survival.

Hilar Cholangiocarcinoma:

partial liver resection is often necessary in addition to extrahepatic biliary excision for complete resection of extrahepatic cholangiocarcinoma.  Review of the relevant literature suggests that the rate of negative-margin resection (no cancer remaining in the body) closely approximates the frequency with which liver resection is performed. That means that chances of completely removing the cancer increase when liver resection done along with cholangiocarcinoma.The proximity of the caudate lobe of liver to the cancer often mandates concomitant caudate lobe removal; this is particularly evident for left-sided hilar tumors, as the major caudate lobe bile ducts drain into the left hepatic bile duct.

Patients undergoing resection exhibited an overall median survival of 35 months; predictors of improved survival were

·      well-differentiated tumors (good cancer biology)

·      negative resection margin (no cancer remaining)

·      the performance of a concomitant liver resection.

The importance of obtaining negative resection margins is underscored by the observation that patients with histologically positive margins (microscopic cancer inside the body ) of resection demonstrated poor survival outcomes indistinguishable from those with locally advanced tumors undergoing operative exploration without attempted resection.

It appears that the performance of liver resection at the time of resection of hilar cholangiocarcinoma is critical for optimizing outcome.

 Indeed, the 5-year actuarial survival among those patients undergoing partial liver resection was 37%, compared with 0% for those treated with bile duct excision alone.

Liver Transplant

Orthotopic liver transplant for cholangiocarcinoma, often done for patients with underlying primary sclerosing cholangitis, has traditionally been associated with suboptimal survival outcomes. Recently, the Mayo Clinic has demonstrated promising results among a select cohort of patients undergoing neoadjuvant chemoradiation followed by cadaveric or living donor liver transplant.

Role of preoperative biliary drainage:

For optimal results and to safely perform major liver resection particularly in cases of cholangiocarcinoma preoperative biliary drainage should be done to decrease bilirubin level less than 5.

Because when bilirubin is higher than than it means that liver is not functioning properly so there are increase chances of infection and post operative liver failure in this group of patients.

Preoperative biliary drainage:

Management of cholangiocarcinoma according to bismuth classification:

Intra Hepatic+ Upper third

Cholangiocarcinomas

without vascular involvement

Type I, II, IIIA

Extended right lobe liver resection with

Caudate lobe

Type III B

Left /Extended left liver resection

preferably with caudate resection

For TYPE IV consider liver transplantation according to mayo protocol

Intra Hepatic+ Upper Third

Cholangiocarcinomas

with vascular involvement :

Liver Resection with Blood vessels resection and reconstruction (if artery/vein inseparable from tumor and achieves margin –ve resection)

Initially it was thought that if tumor involves vessels surgical treatment should not be offered but now it has been proven that with vessles involvement also surgical resection can be offered. With these approaches we can achieve 5 year survival of around 40-50% in these advanced cases also.

Details mentioned in subsequent figures.

Extended right hepatectomy

Here I am posting some pics of extended right liver resection with vascular reconstruction to give you some idea how extensive surgical approach can save life.